Validate screen before constraining window

[MacVim.git] / src / screen.c

/* vi:set ts=8 sts=4 sw=4:
 *
 * VIM - Vi IMproved    by Bram Moolenaar
 *
 * Do ":help uganda"  in Vim to read copying and usage conditions.
 * Do ":help credits" in Vim to see a list of people who contributed.
 * See README.txt for an overview of the Vim source code.
 */

/*
 * screen.c: code for displaying on the screen
 *
 * Output to the screen (console, terminal emulator or GUI window) is minimized
 * by remembering what is already on the screen, and only updating the parts
 * that changed.
 *
 * ScreenLines[off]  Contains a copy of the whole screen, as it is currently
 *                   displayed (excluding text written by external commands).
 * ScreenAttrs[off]  Contains the associated attributes.
 * LineOffset[row]   Contains the offset into ScreenLines*[] and ScreenAttrs[]
 *                   for each line.
 * LineWraps[row]    Flag for each line whether it wraps to the next line.
 *
 * For double-byte characters, two consecutive bytes in ScreenLines[] can form
 * one character which occupies two display cells.
 * For UTF-8 a multi-byte character is converted to Unicode and stored in
 * ScreenLinesUC[].  ScreenLines[] contains the first byte only.  For an ASCII
 * character without composing chars ScreenLinesUC[] will be 0.  When the
 * character occupies two display cells the next byte in ScreenLines[] is 0.
 * ScreenLinesC[][] contain up to 'maxcombine' composing characters
 * (drawn on top of the first character).  They are 0 when not used.
 * ScreenLines2[] is only used for euc-jp to store the second byte if the
 * first byte is 0x8e (single-width character).
 *
 * The screen_*() functions write to the screen and handle updating
 * ScreenLines[].
 *
 * update_screen() is the function that updates all windows and status lines.
 * It is called form the main loop when must_redraw is non-zero.  It may be
 * called from other places when an immediate screen update is needed.
 *
 * The part of the buffer that is displayed in a window is set with:
 * - w_topline (first buffer line in window)
 * - w_topfill (filler line above the first line)
 * - w_leftcol (leftmost window cell in window),
 * - w_skipcol (skipped window cells of first line)
 *
 * Commands that only move the cursor around in a window, do not need to take
 * action to update the display.  The main loop will check if w_topline is
 * valid and update it (scroll the window) when needed.
 *
 * Commands that scroll a window change w_topline and must call
 * check_cursor() to move the cursor into the visible part of the window, and
 * call redraw_later(VALID) to have the window displayed by update_screen()
 * later.
 *
 * Commands that change text in the buffer must call changed_bytes() or
 * changed_lines() to mark the area that changed and will require updating
 * later.  The main loop will call update_screen(), which will update each
 * window that shows the changed buffer.  This assumes text above the change
 * can remain displayed as it is.  Text after the change may need updating for
 * scrolling, folding and syntax highlighting.
 *
 * Commands that change how a window is displayed (e.g., setting 'list') or
 * invalidate the contents of a window in another way (e.g., change fold
 * settings), must call redraw_later(NOT_VALID) to have the whole window
 * redisplayed by update_screen() later.
 *
 * Commands that change how a buffer is displayed (e.g., setting 'tabstop')
 * must call redraw_curbuf_later(NOT_VALID) to have all the windows for the
 * buffer redisplayed by update_screen() later.
 *
 * Commands that change highlighting and possibly cause a scroll too must call
 * redraw_later(SOME_VALID) to update the whole window but still use scrolling
 * to avoid redrawing everything.  But the length of displayed lines must not
 * change, use NOT_VALID then.
 *
 * Commands that move the window position must call redraw_later(NOT_VALID).
 * TODO: should minimize redrawing by scrolling when possible.
 *
 * Commands that change everything (e.g., resizing the screen) must call
 * redraw_all_later(NOT_VALID) or redraw_all_later(CLEAR).
 *
 * Things that are handled indirectly:
 * - When messages scroll the screen up, msg_scrolled will be set and
 *   update_screen() called to redraw.
 */

#include "vim.h"

/*
 * The attributes that are actually active for writing to the screen.
 */
static int      screen_attr = 0;

/*
 * Positioning the cursor is reduced by remembering the last position.
 * Mostly used by windgoto() and screen_char().
 */
static int      screen_cur_row, screen_cur_col; /* last known cursor position */

#ifdef FEAT_SEARCH_EXTRA
static match_T search_hl;       /* used for 'hlsearch' highlight matching */
#endif

#ifdef FEAT_FOLDING
static foldinfo_T win_foldinfo; /* info for 'foldcolumn' */
#endif

/*
 * Buffer for one screen line (characters and attributes).
 */
static schar_T  *current_ScreenLine;

static void win_update __ARGS((win_T *wp));
static void win_draw_end __ARGS((win_T *wp, int c1, int c2, int row, int endrow, hlf_T hl));
#ifdef FEAT_FOLDING
static void fold_line __ARGS((win_T *wp, long fold_count, foldinfo_T *foldinfo, linenr_T lnum, int row));
static void fill_foldcolumn __ARGS((char_u *p, win_T *wp, int closed, linenr_T lnum));
static void copy_text_attr __ARGS((int off, char_u *buf, int len, int attr));
#endif
static int win_line __ARGS((win_T *, linenr_T, int, int, int nochange));
static int char_needs_redraw __ARGS((int off_from, int off_to, int cols));
#ifdef FEAT_RIGHTLEFT
static void screen_line __ARGS((int row, int coloff, int endcol, int clear_width, int rlflag));
# define SCREEN_LINE(r, o, e, c, rl)    screen_line((r), (o), (e), (c), (rl))
#else
static void screen_line __ARGS((int row, int coloff, int endcol, int clear_width));
# define SCREEN_LINE(r, o, e, c, rl)    screen_line((r), (o), (e), (c))
#endif
#ifdef FEAT_VERTSPLIT
static void draw_vsep_win __ARGS((win_T *wp, int row));
#endif
#ifdef FEAT_STL_OPT
static void redraw_custum_statusline __ARGS((win_T *wp));
#endif
#ifdef FEAT_SEARCH_EXTRA
#define SEARCH_HL_PRIORITY 0
static void start_search_hl __ARGS((void));
static void end_search_hl __ARGS((void));
static void prepare_search_hl __ARGS((win_T *wp, linenr_T lnum));
static void next_search_hl __ARGS((win_T *win, match_T *shl, linenr_T lnum, colnr_T mincol));
#endif
static void screen_start_highlight __ARGS((int attr));
static void screen_char __ARGS((unsigned off, int row, int col));
#ifdef FEAT_MBYTE
static void screen_char_2 __ARGS((unsigned off, int row, int col));
#endif
static void screenclear2 __ARGS((void));
static void lineclear __ARGS((unsigned off, int width));
static void lineinvalid __ARGS((unsigned off, int width));
#ifdef FEAT_VERTSPLIT
static void linecopy __ARGS((int to, int from, win_T *wp));
static void redraw_block __ARGS((int row, int end, win_T *wp));
#endif
static int win_do_lines __ARGS((win_T *wp, int row, int line_count, int mayclear, int del));
static void win_rest_invalid __ARGS((win_T *wp));
static void msg_pos_mode __ARGS((void));
#if defined(FEAT_WINDOWS)
static void draw_tabline __ARGS((void));
#endif
#if defined(FEAT_WINDOWS) || defined(FEAT_WILDMENU) || defined(FEAT_STL_OPT)
static int fillchar_status __ARGS((int *attr, int is_curwin));
#endif
#ifdef FEAT_VERTSPLIT
static int fillchar_vsep __ARGS((int *attr));
#endif
#ifdef FEAT_STL_OPT
static void win_redr_custom __ARGS((win_T *wp, int draw_ruler));
#endif
#ifdef FEAT_CMDL_INFO
static void win_redr_ruler __ARGS((win_T *wp, int always));
#endif

#if defined(FEAT_CLIPBOARD) || defined(FEAT_VERTSPLIT)
/* Ugly global: overrule attribute used by screen_char() */
static int screen_char_attr = 0;
#endif

/*
 * Redraw the current window later, with update_screen(type).
 * Set must_redraw only if not already set to a higher value.
 * e.g. if must_redraw is CLEAR, type NOT_VALID will do nothing.
 */
    void
redraw_later(type)
    int         type;
{
    redraw_win_later(curwin, type);
}

    void
redraw_win_later(wp, type)
    win_T       *wp;
    int         type;
{
    if (wp->w_redr_type < type)
    {
        wp->w_redr_type = type;
        if (type >= NOT_VALID)
            wp->w_lines_valid = 0;
        if (must_redraw < type) /* must_redraw is the maximum of all windows */
            must_redraw = type;
    }
}

/*
 * Force a complete redraw later.  Also resets the highlighting.  To be used
 * after executing a shell command that messes up the screen.
 */
    void
redraw_later_clear()
{
    redraw_all_later(CLEAR);
#ifdef FEAT_GUI
    if (gui.in_use)
        /* Use a code that will reset gui.highlight_mask in
         * gui_stop_highlight(). */
        screen_attr = HL_ALL + 1;
    else
#endif
        /* Use attributes that is very unlikely to appear in text. */
        screen_attr = HL_BOLD | HL_UNDERLINE | HL_INVERSE;
}

/*
 * Mark all windows to be redrawn later.
 */
    void
redraw_all_later(type)
    int         type;
{
    win_T       *wp;

    FOR_ALL_WINDOWS(wp)
    {
        redraw_win_later(wp, type);
    }
}

/*
 * Mark all windows that are editing the current buffer to be updated later.
 */
    void
redraw_curbuf_later(type)
    int         type;
{
    redraw_buf_later(curbuf, type);
}

    void
redraw_buf_later(buf, type)
    buf_T       *buf;
    int         type;
{
    win_T       *wp;

    FOR_ALL_WINDOWS(wp)
    {
        if (wp->w_buffer == buf)
            redraw_win_later(wp, type);
    }
}

/*
 * Changed something in the current window, at buffer line "lnum", that
 * requires that line and possibly other lines to be redrawn.
 * Used when entering/leaving Insert mode with the cursor on a folded line.
 * Used to remove the "$" from a change command.
 * Note that when also inserting/deleting lines w_redraw_top and w_redraw_bot
 * may become invalid and the whole window will have to be redrawn.
 */
/*ARGSUSED*/
    void
redrawWinline(lnum, invalid)
    linenr_T    lnum;
    int         invalid;        /* window line height is invalid now */
{
#ifdef FEAT_FOLDING
    int         i;
#endif

    if (curwin->w_redraw_top == 0 || curwin->w_redraw_top > lnum)
        curwin->w_redraw_top = lnum;
    if (curwin->w_redraw_bot == 0 || curwin->w_redraw_bot < lnum)
        curwin->w_redraw_bot = lnum;
    redraw_later(VALID);

#ifdef FEAT_FOLDING
    if (invalid)
    {
        /* A w_lines[] entry for this lnum has become invalid. */
        i = find_wl_entry(curwin, lnum);
        if (i >= 0)
            curwin->w_lines[i].wl_valid = FALSE;
    }
#endif
}

/*
 * update all windows that are editing the current buffer
 */
    void
update_curbuf(type)
    int         type;
{
    redraw_curbuf_later(type);
    update_screen(type);
}

/*
 * update_screen()
 *
 * Based on the current value of curwin->w_topline, transfer a screenfull
 * of stuff from Filemem to ScreenLines[], and update curwin->w_botline.
 */
    void
update_screen(type)
    int         type;
{
    win_T       *wp;
    static int  did_intro = FALSE;
#if defined(FEAT_SEARCH_EXTRA) || defined(FEAT_CLIPBOARD)
    int         did_one;
#endif

    if (!screen_valid(TRUE))
        return;

    if (must_redraw)
    {
        if (type < must_redraw)     /* use maximal type */
            type = must_redraw;

        /* must_redraw is reset here, so that when we run into some weird
         * reason to redraw while busy redrawing (e.g., asynchronous
         * scrolling), or update_topline() in win_update() will cause a
         * scroll, the screen will be redrawn later or in win_update(). */
        must_redraw = 0;
    }

    /* Need to update w_lines[]. */
    if (curwin->w_lines_valid == 0 && type < NOT_VALID)
        type = NOT_VALID;

    if (!redrawing())
    {
        redraw_later(type);             /* remember type for next time */
        must_redraw = type;
        if (type > INVERTED_ALL)
            curwin->w_lines_valid = 0;  /* don't use w_lines[].wl_size now */
        return;
    }

    updating_screen = TRUE;
#ifdef FEAT_SYN_HL
    ++display_tick;         /* let syntax code know we're in a next round of
                             * display updating */
#endif

    /*
     * if the screen was scrolled up when displaying a message, scroll it down
     */
    if (msg_scrolled)
    {
        clear_cmdline = TRUE;
        if (msg_scrolled > Rows - 5)        /* clearing is faster */
            type = CLEAR;
        else if (type != CLEAR)
        {
            check_for_delay(FALSE);
            if (screen_ins_lines(0, 0, msg_scrolled, (int)Rows, NULL) == FAIL)
                type = CLEAR;
            FOR_ALL_WINDOWS(wp)
            {
                if (W_WINROW(wp) < msg_scrolled)
                {
                    if (W_WINROW(wp) + wp->w_height > msg_scrolled
                            && wp->w_redr_type < REDRAW_TOP
                            && wp->w_lines_valid > 0
                            && wp->w_topline == wp->w_lines[0].wl_lnum)
                    {
                        wp->w_upd_rows = msg_scrolled - W_WINROW(wp);
                        wp->w_redr_type = REDRAW_TOP;
                    }
                    else
                    {
                        wp->w_redr_type = NOT_VALID;
#ifdef FEAT_WINDOWS
                        if (W_WINROW(wp) + wp->w_height + W_STATUS_HEIGHT(wp)
                                <= msg_scrolled)
                            wp->w_redr_status = TRUE;
#endif
                    }
                }
            }
            redraw_cmdline = TRUE;
#ifdef FEAT_WINDOWS
            redraw_tabline = TRUE;
#endif
        }
        msg_scrolled = 0;
        need_wait_return = FALSE;
    }

    /* reset cmdline_row now (may have been changed temporarily) */
    compute_cmdrow();

    /* Check for changed highlighting */
    if (need_highlight_changed)
        highlight_changed();

    if (type == CLEAR)          /* first clear screen */
    {
        screenclear();          /* will reset clear_cmdline */
        type = NOT_VALID;
    }

    if (clear_cmdline)          /* going to clear cmdline (done below) */
        check_for_delay(FALSE);

#ifdef FEAT_LINEBREAK
    /* Force redraw when width of 'number' column changes. */
    if (curwin->w_redr_type < NOT_VALID
           && curwin->w_nrwidth != (curwin->w_p_nu ? number_width(curwin) : 0))
        curwin->w_redr_type = NOT_VALID;
#endif

    /*
     * Only start redrawing if there is really something to do.
     */
    if (type == INVERTED)
        update_curswant();
    if (curwin->w_redr_type < type
            && !((type == VALID
                    && curwin->w_lines[0].wl_valid
#ifdef FEAT_DIFF
                    && curwin->w_topfill == curwin->w_old_topfill
                    && curwin->w_botfill == curwin->w_old_botfill
#endif
                    && curwin->w_topline == curwin->w_lines[0].wl_lnum)
#ifdef FEAT_VISUAL
                || (type == INVERTED
                    && VIsual_active
                    && curwin->w_old_cursor_lnum == curwin->w_cursor.lnum
                    && curwin->w_old_visual_mode == VIsual_mode
                    && (curwin->w_valid & VALID_VIRTCOL)
                    && curwin->w_old_curswant == curwin->w_curswant)
#endif
                ))
        curwin->w_redr_type = type;

#ifdef FEAT_WINDOWS
    /* Redraw the tab pages line if needed. */
    if (redraw_tabline || type >= NOT_VALID)
        draw_tabline();
#endif

#ifdef FEAT_SYN_HL
    /*
     * Correct stored syntax highlighting info for changes in each displayed
     * buffer.  Each buffer must only be done once.
     */
    FOR_ALL_WINDOWS(wp)
    {
        if (wp->w_buffer->b_mod_set)
        {
# ifdef FEAT_WINDOWS
            win_T       *wwp;

            /* Check if we already did this buffer. */
            for (wwp = firstwin; wwp != wp; wwp = wwp->w_next)
                if (wwp->w_buffer == wp->w_buffer)
                    break;
# endif
            if (
# ifdef FEAT_WINDOWS
                    wwp == wp &&
# endif
                    syntax_present(wp->w_buffer))
                syn_stack_apply_changes(wp->w_buffer);
        }
    }
#endif

    /*
     * Go from top to bottom through the windows, redrawing the ones that need
     * it.
     */
#if defined(FEAT_SEARCH_EXTRA) || defined(FEAT_CLIPBOARD)
    did_one = FALSE;
#endif
#ifdef FEAT_SEARCH_EXTRA
    search_hl.rm.regprog = NULL;
#endif
    FOR_ALL_WINDOWS(wp)
    {
        if (wp->w_redr_type != 0)
        {
            cursor_off();
#if defined(FEAT_SEARCH_EXTRA) || defined(FEAT_CLIPBOARD)
            if (!did_one)
            {
                did_one = TRUE;
# ifdef FEAT_SEARCH_EXTRA
                start_search_hl();
# endif
# ifdef FEAT_CLIPBOARD
                /* When Visual area changed, may have to update selection. */
                if (clip_star.available && clip_isautosel())
                    clip_update_selection();
# endif
#ifdef FEAT_GUI
                /* Remove the cursor before starting to do anything, because
                 * scrolling may make it difficult to redraw the text under
                 * it. */
                if (gui.in_use)
                    gui_undraw_cursor();
#endif
            }
#endif
            win_update(wp);
        }

#ifdef FEAT_WINDOWS
        /* redraw status line after the window to minimize cursor movement */
        if (wp->w_redr_status)
        {
            cursor_off();
            win_redr_status(wp);
        }
#endif
    }
#if defined(FEAT_SEARCH_EXTRA)
    end_search_hl();
#endif

#ifdef FEAT_WINDOWS
    /* Reset b_mod_set flags.  Going through all windows is probably faster
     * than going through all buffers (there could be many buffers). */
    for (wp = firstwin; wp != NULL; wp = wp->w_next)
        wp->w_buffer->b_mod_set = FALSE;
#else
        curbuf->b_mod_set = FALSE;
#endif

    updating_screen = FALSE;
#ifdef FEAT_GUI
    gui_may_resize_shell();
#endif

    /* Clear or redraw the command line.  Done last, because scrolling may
     * mess up the command line. */
    if (clear_cmdline || redraw_cmdline)
        showmode();

    /* May put up an introductory message when not editing a file */
    if (!did_intro && bufempty()
            && curbuf->b_fname == NULL
#ifdef FEAT_WINDOWS
            && firstwin->w_next == NULL
#endif
            && vim_strchr(p_shm, SHM_INTRO) == NULL)
        intro_message(FALSE);
    did_intro = TRUE;

#ifdef FEAT_GUI
    /* Redraw the cursor and update the scrollbars when all screen updating is
     * done. */
    if (gui.in_use)
    {
        out_flush();    /* required before updating the cursor */
        if (did_one)
            gui_update_cursor(FALSE, FALSE);
        gui_update_scrollbars(FALSE);
    }
#endif
}

#if defined(FEAT_SIGNS) || defined(FEAT_GUI)
static void update_prepare __ARGS((void));
static void update_finish __ARGS((void));

/*
 * Prepare for updating one or more windows.
 */
    static void
update_prepare()
{
    cursor_off();
    updating_screen = TRUE;
#ifdef FEAT_GUI
    /* Remove the cursor before starting to do anything, because scrolling may
     * make it difficult to redraw the text under it. */
    if (gui.in_use)
        gui_undraw_cursor();
#endif
#ifdef FEAT_SEARCH_EXTRA
    start_search_hl();
#endif
}

/*
 * Finish updating one or more windows.
 */
    static void
update_finish()
{
    if (redraw_cmdline)
        showmode();

# ifdef FEAT_SEARCH_EXTRA
    end_search_hl();
# endif

    updating_screen = FALSE;

# ifdef FEAT_GUI
    gui_may_resize_shell();

    /* Redraw the cursor and update the scrollbars when all screen updating is
     * done. */
    if (gui.in_use)
    {
        out_flush();    /* required before updating the cursor */
        gui_update_cursor(FALSE, FALSE);
        gui_update_scrollbars(FALSE);
    }
# endif
}
#endif

#if defined(FEAT_SIGNS) || defined(PROTO)
    void
update_debug_sign(buf, lnum)
    buf_T       *buf;
    linenr_T    lnum;
{
    win_T       *wp;
    int         doit = FALSE;

# ifdef FEAT_FOLDING
    win_foldinfo.fi_level = 0;
# endif

    /* update/delete a specific mark */
    FOR_ALL_WINDOWS(wp)
    {
        if (buf != NULL && lnum > 0)
        {
            if (wp->w_buffer == buf && lnum >= wp->w_topline
                                                      && lnum < wp->w_botline)
            {
                if (wp->w_redraw_top == 0 || wp->w_redraw_top > lnum)
                    wp->w_redraw_top = lnum;
                if (wp->w_redraw_bot == 0 || wp->w_redraw_bot < lnum)
                    wp->w_redraw_bot = lnum;
                redraw_win_later(wp, VALID);
            }
        }
        else
            redraw_win_later(wp, VALID);
        if (wp->w_redr_type != 0)
            doit = TRUE;
    }

    if (!doit)
        return;

    /* update all windows that need updating */
    update_prepare();

# ifdef FEAT_WINDOWS
    for (wp = firstwin; wp; wp = wp->w_next)
    {
        if (wp->w_redr_type != 0)
            win_update(wp);
        if (wp->w_redr_status)
            win_redr_status(wp);
    }
# else
    if (curwin->w_redr_type != 0)
        win_update(curwin);
# endif

    update_finish();
}
#endif


#if defined(FEAT_GUI) || defined(PROTO)
/*
 * Update a single window, its status line and maybe the command line msg.
 * Used for the GUI scrollbar.
 */
    void
updateWindow(wp)
    win_T       *wp;
{
    update_prepare();

#ifdef FEAT_CLIPBOARD
    /* When Visual area changed, may have to update selection. */
    if (clip_star.available && clip_isautosel())
        clip_update_selection();
#endif

    win_update(wp);

#ifdef FEAT_WINDOWS
    /* When the screen was cleared redraw the tab pages line. */
    if (redraw_tabline)
        draw_tabline();

    if (wp->w_redr_status
# ifdef FEAT_CMDL_INFO
            || p_ru
# endif
# ifdef FEAT_STL_OPT
            || *p_stl != NUL || *wp->w_p_stl != NUL
# endif
            )
        win_redr_status(wp);
#endif

    update_finish();
}
#endif

/*
 * Update a single window.
 *
 * This may cause the windows below it also to be redrawn (when clearing the
 * screen or scrolling lines).
 *
 * How the window is redrawn depends on wp->w_redr_type.  Each type also
 * implies the one below it.
 * NOT_VALID    redraw the whole window
 * SOME_VALID   redraw the whole window but do scroll when possible
 * REDRAW_TOP   redraw the top w_upd_rows window lines, otherwise like VALID
 * INVERTED     redraw the changed part of the Visual area
 * INVERTED_ALL redraw the whole Visual area
 * VALID        1. scroll up/down to adjust for a changed w_topline
 *              2. update lines at the top when scrolled down
 *              3. redraw changed text:
 *                 - if wp->w_buffer->b_mod_set set, update lines between
 *                   b_mod_top and b_mod_bot.
 *                 - if wp->w_redraw_top non-zero, redraw lines between
 *                   wp->w_redraw_top and wp->w_redr_bot.
 *                 - continue redrawing when syntax status is invalid.
 *              4. if scrolled up, update lines at the bottom.
 * This results in three areas that may need updating:
 * top: from first row to top_end (when scrolled down)
 * mid: from mid_start to mid_end (update inversion or changed text)
 * bot: from bot_start to last row (when scrolled up)
 */
    static void
win_update(wp)
    win_T       *wp;
{
    buf_T       *buf = wp->w_buffer;
    int         type;
    int         top_end = 0;    /* Below last row of the top area that needs
                                   updating.  0 when no top area updating. */
    int         mid_start = 999;/* first row of the mid area that needs
                                   updating.  999 when no mid area updating. */
    int         mid_end = 0;    /* Below last row of the mid area that needs
                                   updating.  0 when no mid area updating. */
    int         bot_start = 999;/* first row of the bot area that needs
                                   updating.  999 when no bot area updating */
#ifdef FEAT_VISUAL
    int         scrolled_down = FALSE;  /* TRUE when scrolled down when
                                           w_topline got smaller a bit */
#endif
#ifdef FEAT_SEARCH_EXTRA
    matchitem_T *cur;           /* points to the match list */
    int         top_to_mod = FALSE;    /* redraw above mod_top */
#endif

    int         row;            /* current window row to display */
    linenr_T    lnum;           /* current buffer lnum to display */
    int         idx;            /* current index in w_lines[] */
    int         srow;           /* starting row of the current line */

    int         eof = FALSE;    /* if TRUE, we hit the end of the file */
    int         didline = FALSE; /* if TRUE, we finished the last line */
    int         i;
    long        j;
    static int  recursive = FALSE;      /* being called recursively */
    int         old_botline = wp->w_botline;
#ifdef FEAT_FOLDING
    long        fold_count;
#endif
#ifdef FEAT_SYN_HL
    /* remember what happened to the previous line, to know if
     * check_visual_highlight() can be used */
#define DID_NONE 1      /* didn't update a line */
#define DID_LINE 2      /* updated a normal line */
#define DID_FOLD 3      /* updated a folded line */
    int         did_update = DID_NONE;
    linenr_T    syntax_last_parsed = 0;         /* last parsed text line */
#endif
    linenr_T    mod_top = 0;
    linenr_T    mod_bot = 0;
#if defined(FEAT_SYN_HL) || defined(FEAT_SEARCH_EXTRA)
    int         save_got_int;
#endif

    type = wp->w_redr_type;

    if (type == NOT_VALID)
    {
#ifdef FEAT_WINDOWS
        wp->w_redr_status = TRUE;
#endif
        wp->w_lines_valid = 0;
    }

    /* Window is zero-height: nothing to draw. */
    if (wp->w_height == 0)
    {
        wp->w_redr_type = 0;
        return;
    }

#ifdef FEAT_VERTSPLIT
    /* Window is zero-width: Only need to draw the separator. */
    if (wp->w_width == 0)
    {
        /* draw the vertical separator right of this window */
        draw_vsep_win(wp, 0);
        wp->w_redr_type = 0;
        return;
    }
#endif

#ifdef FEAT_SEARCH_EXTRA
    /* Setup for match and 'hlsearch' highlighting.  Disable any previous
     * match */
    cur = wp->w_match_head;
    while (cur != NULL)
    {
        cur->hl.rm = cur->match;
        if (cur->hlg_id == 0)
            cur->hl.attr = 0;
        else
            cur->hl.attr = syn_id2attr(cur->hlg_id);
        cur->hl.buf = buf;
        cur->hl.lnum = 0;
        cur->hl.first_lnum = 0;
# ifdef FEAT_RELTIME
        /* Set the time limit to 'redrawtime'. */
        profile_setlimit(p_rdt, &(cur->hl.tm));
# endif
        cur = cur->next;
    }
    search_hl.buf = buf;
    search_hl.lnum = 0;
    search_hl.first_lnum = 0;
    /* time limit is set at the toplevel, for all windows */
#endif

#ifdef FEAT_LINEBREAK
    /* Force redraw when width of 'number' column changes. */
    i = wp->w_p_nu ? number_width(wp) : 0;
    if (wp->w_nrwidth != i)
    {
        type = NOT_VALID;
        wp->w_nrwidth = i;
    }
    else
#endif

    if (buf->b_mod_set && buf->b_mod_xlines != 0 && wp->w_redraw_top != 0)
    {
        /*
         * When there are both inserted/deleted lines and specific lines to be
         * redrawn, w_redraw_top and w_redraw_bot may be invalid, just redraw
         * everything (only happens when redrawing is off for while).
         */
        type = NOT_VALID;
    }
    else
    {
        /*
         * Set mod_top to the first line that needs displaying because of
         * changes.  Set mod_bot to the first line after the changes.
         */
        mod_top = wp->w_redraw_top;
        if (wp->w_redraw_bot != 0)
            mod_bot = wp->w_redraw_bot + 1;
        else
            mod_bot = 0;
        wp->w_redraw_top = 0;   /* reset for next time */
        wp->w_redraw_bot = 0;
        if (buf->b_mod_set)
        {
            if (mod_top == 0 || mod_top > buf->b_mod_top)
            {
                mod_top = buf->b_mod_top;
#ifdef FEAT_SYN_HL
                /* Need to redraw lines above the change that may be included
                 * in a pattern match. */
                if (syntax_present(buf))
                {
                    mod_top -= buf->b_syn_sync_linebreaks;
                    if (mod_top < 1)
                        mod_top = 1;
                }
#endif
            }
            if (mod_bot == 0 || mod_bot < buf->b_mod_bot)
                mod_bot = buf->b_mod_bot;

#ifdef FEAT_SEARCH_EXTRA
            /* When 'hlsearch' is on and using a multi-line search pattern, a
             * change in one line may make the Search highlighting in a
             * previous line invalid.  Simple solution: redraw all visible
             * lines above the change.
             * Same for a match pattern.
             */
            if (search_hl.rm.regprog != NULL
                                        && re_multiline(search_hl.rm.regprog))
                top_to_mod = TRUE;
            else
            {
                cur = wp->w_match_head;
                while (cur != NULL)
                {
                    if (cur->match.regprog != NULL
                                           && re_multiline(cur->match.regprog))
                    {
                        top_to_mod = TRUE;
                        break;
                    }
                    cur = cur->next;
                }
            }
#endif
        }
#ifdef FEAT_FOLDING
        if (mod_top != 0 && hasAnyFolding(wp))
        {
            linenr_T    lnumt, lnumb;

            /*
             * A change in a line can cause lines above it to become folded or
             * unfolded.  Find the top most buffer line that may be affected.
             * If the line was previously folded and displayed, get the first
             * line of that fold.  If the line is folded now, get the first
             * folded line.  Use the minimum of these two.
             */

            /* Find last valid w_lines[] entry above mod_top.  Set lnumt to
             * the line below it.  If there is no valid entry, use w_topline.
             * Find the first valid w_lines[] entry below mod_bot.  Set lnumb
             * to this line.  If there is no valid entry, use MAXLNUM. */
            lnumt = wp->w_topline;
            lnumb = MAXLNUM;
            for (i = 0; i < wp->w_lines_valid; ++i)
                if (wp->w_lines[i].wl_valid)
                {
                    if (wp->w_lines[i].wl_lastlnum < mod_top)
                        lnumt = wp->w_lines[i].wl_lastlnum + 1;
                    if (lnumb == MAXLNUM && wp->w_lines[i].wl_lnum >= mod_bot)
                    {
                        lnumb = wp->w_lines[i].wl_lnum;
                        /* When there is a fold column it might need updating
                         * in the next line ("J" just above an open fold). */
                        if (wp->w_p_fdc > 0)
                            ++lnumb;
                    }
                }

            (void)hasFoldingWin(wp, mod_top, &mod_top, NULL, TRUE, NULL);
            if (mod_top > lnumt)
                mod_top = lnumt;

            /* Now do the same for the bottom line (one above mod_bot). */
            --mod_bot;
            (void)hasFoldingWin(wp, mod_bot, NULL, &mod_bot, TRUE, NULL);
            ++mod_bot;
            if (mod_bot < lnumb)
                mod_bot = lnumb;
        }
#endif

        /* When a change starts above w_topline and the end is below
         * w_topline, start redrawing at w_topline.
         * If the end of the change is above w_topline: do like no change was
         * made, but redraw the first line to find changes in syntax. */
        if (mod_top != 0 && mod_top < wp->w_topline)
        {
            if (mod_bot > wp->w_topline)
                mod_top = wp->w_topline;
#ifdef FEAT_SYN_HL
            else if (syntax_present(buf))
                top_end = 1;
#endif
        }

        /* When line numbers are displayed need to redraw all lines below
         * inserted/deleted lines. */
        if (mod_top != 0 && buf->b_mod_xlines != 0 && wp->w_p_nu)
            mod_bot = MAXLNUM;
    }

    /*
     * When only displaying the lines at the top, set top_end.  Used when
     * window has scrolled down for msg_scrolled.
     */
    if (type == REDRAW_TOP)
    {
        j = 0;
        for (i = 0; i < wp->w_lines_valid; ++i)
        {
            j += wp->w_lines[i].wl_size;
            if (j >= wp->w_upd_rows)
            {
                top_end = j;
                break;
            }
        }
        if (top_end == 0)
            /* not found (cannot happen?): redraw everything */
            type = NOT_VALID;
        else
            /* top area defined, the rest is VALID */
            type = VALID;
    }

    /* Trick: we want to avoid clearing the screen twice.  screenclear() will
     * set "screen_cleared" to TRUE.  The special value MAYBE (which is still
     * non-zero and thus not FALSE) will indicate that screenclear() was not
     * called. */
    if (screen_cleared)
        screen_cleared = MAYBE;

    /*
     * If there are no changes on the screen that require a complete redraw,
     * handle three cases:
     * 1: we are off the top of the screen by a few lines: scroll down
     * 2: wp->w_topline is below wp->w_lines[0].wl_lnum: may scroll up
     * 3: wp->w_topline is wp->w_lines[0].wl_lnum: find first entry in
     *    w_lines[] that needs updating.
     */
    if ((type == VALID || type == SOME_VALID
                                  || type == INVERTED || type == INVERTED_ALL)
#ifdef FEAT_DIFF
            && !wp->w_botfill && !wp->w_old_botfill
#endif
            )
    {
        if (mod_top != 0 && wp->w_topline == mod_top)
        {
            /*
             * w_topline is the first changed line, the scrolling will be done
             * further down.
             */
        }
        else if (wp->w_lines[0].wl_valid
                && (wp->w_topline < wp->w_lines[0].wl_lnum
#ifdef FEAT_DIFF
                    || (wp->w_topline == wp->w_lines[0].wl_lnum
                        && wp->w_topfill > wp->w_old_topfill)
#endif
                   ))
        {
            /*
             * New topline is above old topline: May scroll down.
             */
#ifdef FEAT_FOLDING
            if (hasAnyFolding(wp))
            {
                linenr_T ln;

                /* count the number of lines we are off, counting a sequence
                 * of folded lines as one */
                j = 0;
                for (ln = wp->w_topline; ln < wp->w_lines[0].wl_lnum; ++ln)
                {
                    ++j;
                    if (j >= wp->w_height - 2)
                        break;
                    (void)hasFoldingWin(wp, ln, NULL, &ln, TRUE, NULL);
                }
            }
            else
#endif
                j = wp->w_lines[0].wl_lnum - wp->w_topline;
            if (j < wp->w_height - 2)           /* not too far off */
            {
                i = plines_m_win(wp, wp->w_topline, wp->w_lines[0].wl_lnum - 1);
#ifdef FEAT_DIFF
                /* insert extra lines for previously invisible filler lines */
                if (wp->w_lines[0].wl_lnum != wp->w_topline)
                    i += diff_check_fill(wp, wp->w_lines[0].wl_lnum)
                                                          - wp->w_old_topfill;
#endif
                if (i < wp->w_height - 2)       /* less than a screen off */
                {
                    /*
                     * Try to insert the correct number of lines.
                     * If not the last window, delete the lines at the bottom.
                     * win_ins_lines may fail when the terminal can't do it.
                     */
                    if (i > 0)
                        check_for_delay(FALSE);
                    if (win_ins_lines(wp, 0, i, FALSE, wp == firstwin) == OK)
                    {
                        if (wp->w_lines_valid != 0)
                        {
                            /* Need to update rows that are new, stop at the
                             * first one that scrolled down. */
                            top_end = i;
#ifdef FEAT_VISUAL
                            scrolled_down = TRUE;
#endif

                            /* Move the entries that were scrolled, disable
                             * the entries for the lines to be redrawn. */
                            if ((wp->w_lines_valid += j) > wp->w_height)
                                wp->w_lines_valid = wp->w_height;
                            for (idx = wp->w_lines_valid; idx - j >= 0; idx--)
                                wp->w_lines[idx] = wp->w_lines[idx - j];
                            while (idx >= 0)
                                wp->w_lines[idx--].wl_valid = FALSE;
                        }
                    }
                    else
                        mid_start = 0;          /* redraw all lines */
                }
                else
                    mid_start = 0;              /* redraw all lines */
            }
            else
                mid_start = 0;          /* redraw all lines */
        }
        else
        {
            /*
             * New topline is at or below old topline: May scroll up.
             * When topline didn't change, find first entry in w_lines[] that
             * needs updating.
             */

            /* try to find wp->w_topline in wp->w_lines[].wl_lnum */
            j = -1;
            row = 0;
            for (i = 0; i < wp->w_lines_valid; i++)
            {
                if (wp->w_lines[i].wl_valid
                        && wp->w_lines[i].wl_lnum == wp->w_topline)
                {
                    j = i;
                    break;
                }
                row += wp->w_lines[i].wl_size;
            }
            if (j == -1)
            {
                /* if wp->w_topline is not in wp->w_lines[].wl_lnum redraw all
                 * lines */
                mid_start = 0;
            }
            else
            {
                /*
                 * Try to delete the correct number of lines.
                 * wp->w_topline is at wp->w_lines[i].wl_lnum.
                 */
#ifdef FEAT_DIFF
                /* If the topline didn't change, delete old filler lines,
                 * otherwise delete filler lines of the new topline... */
                if (wp->w_lines[0].wl_lnum == wp->w_topline)
                    row += wp->w_old_topfill;
                else
                    row += diff_check_fill(wp, wp->w_topline);
                /* ... but don't delete new filler lines. */
                row -= wp->w_topfill;
#endif
                if (row > 0)
                {
                    check_for_delay(FALSE);
                    if (win_del_lines(wp, 0, row, FALSE, wp == firstwin) == OK)
                        bot_start = wp->w_height - row;
                    else
                        mid_start = 0;          /* redraw all lines */
                }
                if ((row == 0 || bot_start < 999) && wp->w_lines_valid != 0)
                {
                    /*
                     * Skip the lines (below the deleted lines) that are still
                     * valid and don't need redrawing.  Copy their info
                     * upwards, to compensate for the deleted lines.  Set
                     * bot_start to the first row that needs redrawing.
                     */
                    bot_start = 0;
                    idx = 0;
                    for (;;)
                    {
                        wp->w_lines[idx] = wp->w_lines[j];
                        /* stop at line that didn't fit, unless it is still
                         * valid (no lines deleted) */
                        if (row > 0 && bot_start + row
                                 + (int)wp->w_lines[j].wl_size > wp->w_height)
                        {
                            wp->w_lines_valid = idx + 1;
                            break;
                        }
                        bot_start += wp->w_lines[idx++].wl_size;

                        /* stop at the last valid entry in w_lines[].wl_size */
                        if (++j >= wp->w_lines_valid)
                        {
                            wp->w_lines_valid = idx;
                            break;
                        }
                    }
#ifdef FEAT_DIFF
                    /* Correct the first entry for filler lines at the top
                     * when it won't get updated below. */
                    if (wp->w_p_diff && bot_start > 0)
                        wp->w_lines[0].wl_size =
                            plines_win_nofill(wp, wp->w_topline, TRUE)
                                                              + wp->w_topfill;
#endif
                }
            }
        }

        /* When starting redraw in the first line, redraw all lines.  When
         * there is only one window it's probably faster to clear the screen
         * first. */
        if (mid_start == 0)
        {
            mid_end = wp->w_height;
            if (lastwin == firstwin)
            {
                /* Clear the screen when it was not done by win_del_lines() or
                 * win_ins_lines() above, "screen_cleared" is FALSE or MAYBE
                 * then. */
                if (screen_cleared != TRUE)
                    screenclear();
#ifdef FEAT_WINDOWS
                /* The screen was cleared, redraw the tab pages line. */
                if (redraw_tabline)
                    draw_tabline();
#endif
            }
        }

        /* When win_del_lines() or win_ins_lines() caused the screen to be
         * cleared (only happens for the first window) or when screenclear()
         * was called directly above, "must_redraw" will have been set to
         * NOT_VALID, need to reset it here to avoid redrawing twice. */
        if (screen_cleared == TRUE)
            must_redraw = 0;
    }
    else
    {
        /* Not VALID or INVERTED: redraw all lines. */
        mid_start = 0;
        mid_end = wp->w_height;
    }

    if (type == SOME_VALID)
    {
        /* SOME_VALID: redraw all lines. */
        mid_start = 0;
        mid_end = wp->w_height;
        type = NOT_VALID;
    }

#ifdef FEAT_VISUAL
    /* check if we are updating or removing the inverted part */
    if ((VIsual_active && buf == curwin->w_buffer)
            || (wp->w_old_cursor_lnum != 0 && type != NOT_VALID))
    {
        linenr_T    from, to;

        if (VIsual_active)
        {
            if (VIsual_active
                    && (VIsual_mode != wp->w_old_visual_mode
                        || type == INVERTED_ALL))
            {
                /*
                 * If the type of Visual selection changed, redraw the whole
                 * selection.  Also when the ownership of the X selection is
                 * gained or lost.
                 */
                if (curwin->w_cursor.lnum < VIsual.lnum)
                {
                    from = curwin->w_cursor.lnum;
                    to = VIsual.lnum;
                }
                else
                {
                    from = VIsual.lnum;
                    to = curwin->w_cursor.lnum;
                }
                /* redraw more when the cursor moved as well */
                if (wp->w_old_cursor_lnum < from)
                    from = wp->w_old_cursor_lnum;
                if (wp->w_old_cursor_lnum > to)
                    to = wp->w_old_cursor_lnum;
                if (wp->w_old_visual_lnum < from)
                    from = wp->w_old_visual_lnum;
                if (wp->w_old_visual_lnum > to)
                    to = wp->w_old_visual_lnum;
            }
            else
            {
                /*
                 * Find the line numbers that need to be updated: The lines
                 * between the old cursor position and the current cursor
                 * position.  Also check if the Visual position changed.
                 */
                if (curwin->w_cursor.lnum < wp->w_old_cursor_lnum)
                {
                    from = curwin->w_cursor.lnum;
                    to = wp->w_old_cursor_lnum;
                }
                else
                {
                    from = wp->w_old_cursor_lnum;
                    to = curwin->w_cursor.lnum;
                    if (from == 0)      /* Visual mode just started */
                        from = to;
                }

                if (VIsual.lnum != wp->w_old_visual_lnum
                                        || VIsual.col != wp->w_old_visual_col)
                {
                    if (wp->w_old_visual_lnum < from
                                                && wp->w_old_visual_lnum != 0)
                        from = wp->w_old_visual_lnum;
                    if (wp->w_old_visual_lnum > to)
                        to = wp->w_old_visual_lnum;
                    if (VIsual.lnum < from)
                        from = VIsual.lnum;
                    if (VIsual.lnum > to)
                        to = VIsual.lnum;
                }
            }

            /*
             * If in block mode and changed column or curwin->w_curswant:
             * update all lines.
             * First compute the actual start and end column.
             */
            if (VIsual_mode == Ctrl_V)
            {
                colnr_T fromc, toc;

                getvcols(wp, &VIsual, &curwin->w_cursor, &fromc, &toc);
                ++toc;
                if (curwin->w_curswant == MAXCOL)
                    toc = MAXCOL;

                if (fromc != wp->w_old_cursor_fcol
                        || toc != wp->w_old_cursor_lcol)
                {
                    if (from > VIsual.lnum)
                        from = VIsual.lnum;
                    if (to < VIsual.lnum)
                        to = VIsual.lnum;
                }
                wp->w_old_cursor_fcol = fromc;
                wp->w_old_cursor_lcol = toc;
            }
        }
        else
        {
            /* Use the line numbers of the old Visual area. */
            if (wp->w_old_cursor_lnum < wp->w_old_visual_lnum)
            {
                from = wp->w_old_cursor_lnum;
                to = wp->w_old_visual_lnum;
            }
            else
            {
                from = wp->w_old_visual_lnum;
                to = wp->w_old_cursor_lnum;
            }
        }

        /*
         * There is no need to update lines above the top of the window.
         */
        if (from < wp->w_topline)
            from = wp->w_topline;

        /*
         * If we know the value of w_botline, use it to restrict the update to
         * the lines that are visible in the window.
         */
        if (wp->w_valid & VALID_BOTLINE)
        {
            if (from >= wp->w_botline)
                from = wp->w_botline - 1;
            if (to >= wp->w_botline)
                to = wp->w_botline - 1;
        }

        /*
         * Find the minimal part to be updated.
         * Watch out for scrolling that made entries in w_lines[] invalid.
         * E.g., CTRL-U makes the first half of w_lines[] invalid and sets
         * top_end; need to redraw from top_end to the "to" line.
         * A middle mouse click with a Visual selection may change the text
         * above the Visual area and reset wl_valid, do count these for
         * mid_end (in srow).
         */
        if (mid_start > 0)
        {
            lnum = wp->w_topline;
            idx = 0;
            srow = 0;
            if (scrolled_down)
                mid_start = top_end;
            else
                mid_start = 0;
            while (lnum < from && idx < wp->w_lines_valid)      /* find start */
            {
                if (wp->w_lines[idx].wl_valid)
                    mid_start += wp->w_lines[idx].wl_size;
                else if (!scrolled_down)
                    srow += wp->w_lines[idx].wl_size;
                ++idx;
# ifdef FEAT_FOLDING
                if (idx < wp->w_lines_valid && wp->w_lines[idx].wl_valid)
                    lnum = wp->w_lines[idx].wl_lnum;
                else
# endif
                    ++lnum;
            }
            srow += mid_start;
            mid_end = wp->w_height;
            for ( ; idx < wp->w_lines_valid; ++idx)             /* find end */
            {
                if (wp->w_lines[idx].wl_valid
                        && wp->w_lines[idx].wl_lnum >= to + 1)
                {
                    /* Only update until first row of this line */
                    mid_end = srow;
                    break;
                }
                srow += wp->w_lines[idx].wl_size;
            }
        }
    }

    if (VIsual_active && buf == curwin->w_buffer)
    {
        wp->w_old_visual_mode = VIsual_mode;
        wp->w_old_cursor_lnum = curwin->w_cursor.lnum;
        wp->w_old_visual_lnum = VIsual.lnum;
        wp->w_old_visual_col = VIsual.col;
        wp->w_old_curswant = curwin->w_curswant;
    }
    else
    {
        wp->w_old_visual_mode = 0;
        wp->w_old_cursor_lnum = 0;
        wp->w_old_visual_lnum = 0;
        wp->w_old_visual_col = 0;
    }
#endif /* FEAT_VISUAL */

#if defined(FEAT_SYN_HL) || defined(FEAT_SEARCH_EXTRA)
    /* reset got_int, otherwise regexp won't work */
    save_got_int = got_int;
    got_int = 0;
#endif
#ifdef FEAT_FOLDING
    win_foldinfo.fi_level = 0;
#endif

    /*
     * Update all the window rows.
     */
    idx = 0;            /* first entry in w_lines[].wl_size */
    row = 0;
    srow = 0;
    lnum = wp->w_topline;       /* first line shown in window */
    for (;;)
    {
        /* stop updating when reached the end of the window (check for _past_
         * the end of the window is at the end of the loop) */
        if (row == wp->w_height)
        {
            didline = TRUE;
            break;
        }

        /* stop updating when hit the end of the file */
        if (lnum > buf->b_ml.ml_line_count)
        {
            eof = TRUE;
            break;
        }

        /* Remember the starting row of the line that is going to be dealt
         * with.  It is used further down when the line doesn't fit. */
        srow = row;

        /*
         * Update a line when it is in an area that needs updating, when it
         * has changes or w_lines[idx] is invalid.
         * bot_start may be halfway a wrapped line after using
         * win_del_lines(), check if the current line includes it.
         * When syntax folding is being used, the saved syntax states will
         * already have been updated, we can't see where the syntax state is
         * the same again, just update until the end of the window.
         */
        if (row < top_end
                || (row >= mid_start && row < mid_end)
#ifdef FEAT_SEARCH_EXTRA
                || top_to_mod
#endif
                || idx >= wp->w_lines_valid
                || (row + wp->w_lines[idx].wl_size > bot_start)
                || (mod_top != 0
                    && (lnum == mod_top
                        || (lnum >= mod_top
                            && (lnum < mod_bot
#ifdef FEAT_SYN_HL
                                || did_update == DID_FOLD
                                || (did_update == DID_LINE
                                    && syntax_present(buf)
                                    && (
# ifdef FEAT_FOLDING
                                        (foldmethodIsSyntax(wp)
                                                      && hasAnyFolding(wp)) ||
# endif
                                        syntax_check_changed(lnum)))
#endif
                                )))))
        {
#ifdef FEAT_SEARCH_EXTRA
            if (lnum == mod_top)
                top_to_mod = FALSE;
#endif

            /*
             * When at start of changed lines: May scroll following lines
             * up or down to minimize redrawing.
             * Don't do this when the change continues until the end.
             * Don't scroll when dollar_vcol is non-zero, keep the "$".
             */
            if (lnum == mod_top
                    && mod_bot != MAXLNUM
                    && !(dollar_vcol != 0 && mod_bot == mod_top + 1))
            {
                int             old_rows = 0;
                int             new_rows = 0;
                int             xtra_rows;
                linenr_T        l;

                /* Count the old number of window rows, using w_lines[], which
                 * should still contain the sizes for the lines as they are
                 * currently displayed. */
                for (i = idx; i < wp->w_lines_valid; ++i)
                {
                    /* Only valid lines have a meaningful wl_lnum.  Invalid
                     * lines are part of the changed area. */
                    if (wp->w_lines[i].wl_valid
                            && wp->w_lines[i].wl_lnum == mod_bot)
                        break;
                    old_rows += wp->w_lines[i].wl_size;
#ifdef FEAT_FOLDING
                    if (wp->w_lines[i].wl_valid
                            && wp->w_lines[i].wl_lastlnum + 1 == mod_bot)
                    {
                        /* Must have found the last valid entry above mod_bot.
                         * Add following invalid entries. */
                        ++i;
                        while (i < wp->w_lines_valid
                                                  && !wp->w_lines[i].wl_valid)
                            old_rows += wp->w_lines[i++].wl_size;
                        break;
                    }
#endif
                }

                if (i >= wp->w_lines_valid)
                {
                    /* We can't find a valid line below the changed lines,
                     * need to redraw until the end of the window.
                     * Inserting/deleting lines has no use. */
                    bot_start = 0;
                }
                else
                {
                    /* Able to count old number of rows: Count new window
                     * rows, and may insert/delete lines */
                    j = idx;
                    for (l = lnum; l < mod_bot; ++l)
                    {
#ifdef FEAT_FOLDING
                        if (hasFoldingWin(wp, l, NULL, &l, TRUE, NULL))
                            ++new_rows;
                        else
#endif
#ifdef FEAT_DIFF
                            if (l == wp->w_topline)
                            new_rows += plines_win_nofill(wp, l, TRUE)
                                                              + wp->w_topfill;
                        else
#endif
                            new_rows += plines_win(wp, l, TRUE);
                        ++j;
                        if (new_rows > wp->w_height - row - 2)
                        {
                            /* it's getting too much, must redraw the rest */
                            new_rows = 9999;
                            break;
                        }
                    }
                    xtra_rows = new_rows - old_rows;
                    if (xtra_rows < 0)
                    {
                        /* May scroll text up.  If there is not enough
                         * remaining text or scrolling fails, must redraw the
                         * rest.  If scrolling works, must redraw the text
                         * below the scrolled text. */
                        if (row - xtra_rows >= wp->w_height - 2)
                            mod_bot = MAXLNUM;
                        else
                        {
                            check_for_delay(FALSE);
                            if (win_del_lines(wp, row,
                                            -xtra_rows, FALSE, FALSE) == FAIL)
                                mod_bot = MAXLNUM;
                            else
                                bot_start = wp->w_height + xtra_rows;
                        }
                    }
                    else if (xtra_rows > 0)
                    {
                        /* May scroll text down.  If there is not enough
                         * remaining text of scrolling fails, must redraw the
                         * rest. */
                        if (row + xtra_rows >= wp->w_height - 2)
                            mod_bot = MAXLNUM;
                        else
                        {
                            check_for_delay(FALSE);
                            if (win_ins_lines(wp, row + old_rows,
                                             xtra_rows, FALSE, FALSE) == FAIL)
                                mod_bot = MAXLNUM;
                            else if (top_end > row + old_rows)
                                /* Scrolled the part at the top that requires
                                 * updating down. */
                                top_end += xtra_rows;
                        }
                    }

                    /* When not updating the rest, may need to move w_lines[]
                     * entries. */
                    if (mod_bot != MAXLNUM && i != j)
                    {
                        if (j < i)
                        {
                            int x = row + new_rows;

                            /* move entries in w_lines[] upwards */
                            for (;;)
                            {
                                /* stop at last valid entry in w_lines[] */
                                if (i >= wp->w_lines_valid)
                                {
                                    wp->w_lines_valid = j;
                                    break;
                                }
                                wp->w_lines[j] = wp->w_lines[i];
                                /* stop at a line that won't fit */
                                if (x + (int)wp->w_lines[j].wl_size
                                                           > wp->w_height)
                                {
                                    wp->w_lines_valid = j + 1;
                                    break;
                                }
                                x += wp->w_lines[j++].wl_size;
                                ++i;
                            }
                            if (bot_start > x)
                                bot_start = x;
                        }
                        else /* j > i */
                        {
                            /* move entries in w_lines[] downwards */
                            j -= i;
                            wp->w_lines_valid += j;
                            if (wp->w_lines_valid > wp->w_height)
                                wp->w_lines_valid = wp->w_height;
                            for (i = wp->w_lines_valid; i - j >= idx; --i)
                                wp->w_lines[i] = wp->w_lines[i - j];

                            /* The w_lines[] entries for inserted lines are
                             * now invalid, but wl_size may be used above.
                             * Reset to zero. */
                            while (i >= idx)
                            {
                                wp->w_lines[i].wl_size = 0;
                                wp->w_lines[i--].wl_valid = FALSE;
                            }
                        }
                    }
                }
            }

#ifdef FEAT_FOLDING
            /*
             * When lines are folded, display one line for all of them.
             * Otherwise, display normally (can be several display lines when
             * 'wrap' is on).
             */
            fold_count = foldedCount(wp, lnum, &win_foldinfo);
            if (fold_count != 0)
            {
                fold_line(wp, fold_count, &win_foldinfo, lnum, row);
                ++row;
                --fold_count;
                wp->w_lines[idx].wl_folded = TRUE;
                wp->w_lines[idx].wl_lastlnum = lnum + fold_count;
# ifdef FEAT_SYN_HL
                did_update = DID_FOLD;
# endif
            }
            else
#endif
            if (idx < wp->w_lines_valid
                    && wp->w_lines[idx].wl_valid
                    && wp->w_lines[idx].wl_lnum == lnum
                    && lnum > wp->w_topline
                    && !(dy_flags & DY_LASTLINE)
                    && srow + wp->w_lines[idx].wl_size > wp->w_height
#ifdef FEAT_DIFF
                    && diff_check_fill(wp, lnum) == 0
#endif
                    )
            {
                /* This line is not going to fit.  Don't draw anything here,
                 * will draw "@  " lines below. */
                row = wp->w_height + 1;
            }
            else
            {
#ifdef FEAT_SEARCH_EXTRA
                prepare_search_hl(wp, lnum);
#endif
#ifdef FEAT_SYN_HL
                /* Let the syntax stuff know we skipped a few lines. */
                if (syntax_last_parsed != 0 && syntax_last_parsed + 1 < lnum
                                                       && syntax_present(buf))
                    syntax_end_parsing(syntax_last_parsed + 1);
#endif

                /*
                 * Display one line.
                 */
                row = win_line(wp, lnum, srow, wp->w_height, mod_top == 0);

#ifdef FEAT_FOLDING
                wp->w_lines[idx].wl_folded = FALSE;
                wp->w_lines[idx].wl_lastlnum = lnum;
#endif
#ifdef FEAT_SYN_HL
                did_update = DID_LINE;
                syntax_last_parsed = lnum;
#endif
            }

            wp->w_lines[idx].wl_lnum = lnum;
            wp->w_lines[idx].wl_valid = TRUE;
            if (row > wp->w_height)     /* past end of screen */
            {
                /* we may need the size of that too long line later on */
                if (dollar_vcol == 0)
                    wp->w_lines[idx].wl_size = plines_win(wp, lnum, TRUE);
                ++idx;
                break;
            }
            if (dollar_vcol == 0)
                wp->w_lines[idx].wl_size = row - srow;
            ++idx;
#ifdef FEAT_FOLDING
            lnum += fold_count + 1;
#else
            ++lnum;
#endif
        }
        else
        {
            /* This line does not need updating, advance to the next one */
            row += wp->w_lines[idx++].wl_size;
            if (row > wp->w_height)     /* past end of screen */
                break;
#ifdef FEAT_FOLDING
            lnum = wp->w_lines[idx - 1].wl_lastlnum + 1;
#else
            ++lnum;
#endif
#ifdef FEAT_SYN_HL
            did_update = DID_NONE;
#endif
        }

        if (lnum > buf->b_ml.ml_line_count)
        {
            eof = TRUE;
            break;
        }
    }
    /*
     * End of loop over all window lines.
     */


    if (idx > wp->w_lines_valid)
        wp->w_lines_valid = idx;

#ifdef FEAT_SYN_HL
    /*
     * Let the syntax stuff know we stop parsing here.
     */
    if (syntax_last_parsed != 0 && syntax_present(buf))
        syntax_end_parsing(syntax_last_parsed + 1);
#endif

    /*
     * If we didn't hit the end of the file, and we didn't finish the last
     * line we were working on, then the line didn't fit.
     */
    wp->w_empty_rows = 0;
#ifdef FEAT_DIFF
    wp->w_filler_rows = 0;
#endif
    if (!eof && !didline)
    {
        if (lnum == wp->w_topline)
        {
            /*
             * Single line that does not fit!
             * Don't overwrite it, it can be edited.
             */
            wp->w_botline = lnum + 1;
        }
#ifdef FEAT_DIFF
        else if (diff_check_fill(wp, lnum) >= wp->w_height - srow)
        {
            /* Window ends in filler lines. */
            wp->w_botline = lnum;
            wp->w_filler_rows = wp->w_height - srow;
        }
#endif
        else if (dy_flags & DY_LASTLINE)        /* 'display' has "lastline" */
        {
            /*
             * Last line isn't finished: Display "@@@" at the end.
             */
            screen_fill(W_WINROW(wp) + wp->w_height - 1,
                    W_WINROW(wp) + wp->w_height,
                    (int)W_ENDCOL(wp) - 3, (int)W_ENDCOL(wp),
                    '@', '@', hl_attr(HLF_AT));
            set_empty_rows(wp, srow);
            wp->w_botline = lnum;
        }
        else
        {
            win_draw_end(wp, '@', ' ', srow, wp->w_height, HLF_AT);
            wp->w_botline = lnum;
        }
    }
    else
    {
#ifdef FEAT_VERTSPLIT
        draw_vsep_win(wp, row);
#endif
        if (eof)                /* we hit the end of the file */
        {
            wp->w_botline = buf->b_ml.ml_line_count + 1;
#ifdef FEAT_DIFF
            j = diff_check_fill(wp, wp->w_botline);
            if (j > 0 && !wp->w_botfill)
            {
                /*
                 * Display filler lines at the end of the file
                 */
                if (char2cells(fill_diff) > 1)
                    i = '-';
                else
                    i = fill_diff;
                if (row + j > wp->w_height)
                    j = wp->w_height - row;
                win_draw_end(wp, i, i, row, row + (int)j, HLF_DED);
                row += j;
            }
#endif
        }
        else if (dollar_vcol == 0)
            wp->w_botline = lnum;

        /* make sure the rest of the screen is blank */
        /* put '~'s on rows that aren't part of the file. */
        win_draw_end(wp, '~', ' ', row, wp->w_height, HLF_AT);
    }

    /* Reset the type of redrawing required, the window has been updated. */
    wp->w_redr_type = 0;
#ifdef FEAT_DIFF
    wp->w_old_topfill = wp->w_topfill;
    wp->w_old_botfill = wp->w_botfill;
#endif

    if (dollar_vcol == 0)
    {
        /*
         * There is a trick with w_botline.  If we invalidate it on each
         * change that might modify it, this will cause a lot of expensive
         * calls to plines() in update_topline() each time.  Therefore the
         * value of w_botline is often approximated, and this value is used to
         * compute the value of w_topline.  If the value of w_botline was
         * wrong, check that the value of w_topline is correct (cursor is on
         * the visible part of the text).  If it's not, we need to redraw
         * again.  Mostly this just means scrolling up a few lines, so it
         * doesn't look too bad.  Only do this for the current window (where
         * changes are relevant).
         */
        wp->w_valid |= VALID_BOTLINE;
        if (wp == curwin && wp->w_botline != old_botline && !recursive)
        {
            recursive = TRUE;
            curwin->w_valid &= ~VALID_TOPLINE;
            update_topline();   /* may invalidate w_botline again */
            if (must_redraw != 0)
            {
                /* Don't update for changes in buffer again. */
                i = curbuf->b_mod_set;
                curbuf->b_mod_set = FALSE;
                win_update(curwin);
                must_redraw = 0;
                curbuf->b_mod_set = i;
            }
            recursive = FALSE;
        }
    }

#if defined(FEAT_SYN_HL) || defined(FEAT_SEARCH_EXTRA)
    /* restore got_int, unless CTRL-C was hit while redrawing */
    if (!got_int)
        got_int = save_got_int;
#endif
}

#ifdef FEAT_SIGNS
static int draw_signcolumn __ARGS((win_T *wp));

/*
 * Return TRUE when window "wp" has a column to draw signs in.
 */
    static int
draw_signcolumn(wp)
    win_T *wp;
{
    return (wp->w_buffer->b_signlist != NULL
# ifdef FEAT_NETBEANS_INTG
                            || usingNetbeans
# endif
                    );
}
#endif

/*
 * Clear the rest of the window and mark the unused lines with "c1".  use "c2"
 * as the filler character.
 */
    static void
win_draw_end(wp, c1, c2, row, endrow, hl)
    win_T       *wp;
    int         c1;
    int         c2;
    int         row;
    int         endrow;
    hlf_T       hl;
{
#if defined(FEAT_FOLDING) || defined(FEAT_SIGNS) || defined(FEAT_CMDWIN)
    int         n = 0;
# define FDC_OFF n
#else
# define FDC_OFF 0
#endif

#ifdef FEAT_RIGHTLEFT
    if (wp->w_p_rl)
    {
        /* No check for cmdline window: should never be right-left. */
# ifdef FEAT_FOLDING
        n = wp->w_p_fdc;

        if (n > 0)
        {
            /* draw the fold column at the right */
            if (n > W_WIDTH(wp))
                n = W_WIDTH(wp);
            screen_fill(W_WINROW(wp) + row, W_WINROW(wp) + endrow,
                    W_ENDCOL(wp) - n, (int)W_ENDCOL(wp),
                    ' ', ' ', hl_attr(HLF_FC));
        }
# endif
# ifdef FEAT_SIGNS
        if (draw_signcolumn(wp))
        {
            int nn = n + 2;

            /* draw the sign column left of the fold column */
            if (nn > W_WIDTH(wp))
                nn = W_WIDTH(wp);
            screen_fill(W_WINROW(wp) + row, W_WINROW(wp) + endrow,
                    W_ENDCOL(wp) - nn, (int)W_ENDCOL(wp) - n,
                    ' ', ' ', hl_attr(HLF_SC));
            n = nn;
        }
# endif
        screen_fill(W_WINROW(wp) + row, W_WINROW(wp) + endrow,
                W_WINCOL(wp), W_ENDCOL(wp) - 1 - FDC_OFF,
                c2, c2, hl_attr(hl));
        screen_fill(W_WINROW(wp) + row, W_WINROW(wp) + endrow,
                W_ENDCOL(wp) - 1 - FDC_OFF, W_ENDCOL(wp) - FDC_OFF,
                c1, c2, hl_attr(hl));
    }
    else
#endif
    {
#ifdef FEAT_CMDWIN
        if (cmdwin_type != 0 && wp == curwin)
        {
            /* draw the cmdline character in the leftmost column */
            n = 1;
            if (n > wp->w_width)
                n = wp->w_width;
            screen_fill(W_WINROW(wp) + row, W_WINROW(wp) + endrow,
                    W_WINCOL(wp), (int)W_WINCOL(wp) + n,
                    cmdwin_type, ' ', hl_attr(HLF_AT));
        }
#endif
#ifdef FEAT_FOLDING
        if (wp->w_p_fdc > 0)
        {
            int     nn = n + wp->w_p_fdc;

            /* draw the fold column at the left */
            if (nn > W_WIDTH(wp))
                nn = W_WIDTH(wp);
            screen_fill(W_WINROW(wp) + row, W_WINROW(wp) + endrow,
                    W_WINCOL(wp) + n, (int)W_WINCOL(wp) + nn,
                    ' ', ' ', hl_attr(HLF_FC));
            n = nn;
        }
#endif
#ifdef FEAT_SIGNS
        if (draw_signcolumn(wp))
        {
            int     nn = n + 2;

            /* draw the sign column after the fold column */
            if (nn > W_WIDTH(wp))
                nn = W_WIDTH(wp);
            screen_fill(W_WINROW(wp) + row, W_WINROW(wp) + endrow,
                    W_WINCOL(wp) + n, (int)W_WINCOL(wp) + nn,
                    ' ', ' ', hl_attr(HLF_SC));
            n = nn;
        }
#endif
        screen_fill(W_WINROW(wp) + row, W_WINROW(wp) + endrow,
                W_WINCOL(wp) + FDC_OFF, (int)W_ENDCOL(wp),
                c1, c2, hl_attr(hl));
    }
    set_empty_rows(wp, row);
}

#ifdef FEAT_FOLDING
/*
 * Display one folded line.
 */
    static void
fold_line(wp, fold_count, foldinfo, lnum, row)
    win_T       *wp;
    long        fold_count;
    foldinfo_T  *foldinfo;
    linenr_T    lnum;
    int         row;
{
    char_u      buf[51];
    pos_T       *top, *bot;
    linenr_T    lnume = lnum + fold_count - 1;
    int         len;
    char_u      *text;
    int         fdc;
    int         col;
    int         txtcol;
    int         off = (int)(current_ScreenLine - ScreenLines);
    int         ri;

    /* Build the fold line:
     * 1. Add the cmdwin_type for the command-line window
     * 2. Add the 'foldcolumn'
     * 3. Add the 'number' column
     * 4. Compose the text
     * 5. Add the text
     * 6. set highlighting for the Visual area an other text
     */
    col = 0;

    /*
     * 1. Add the cmdwin_type for the command-line window
     * Ignores 'rightleft', this window is never right-left.
     */
#ifdef FEAT_CMDWIN
    if (cmdwin_type != 0 && wp == curwin)
    {
        ScreenLines[off] = cmdwin_type;
        ScreenAttrs[off] = hl_attr(HLF_AT);
#ifdef FEAT_MBYTE
        if (enc_utf8)
            ScreenLinesUC[off] = 0;
#endif
        ++col;
    }
#endif

    /*
     * 2. Add the 'foldcolumn'
     */
    fdc = wp->w_p_fdc;
    if (fdc > W_WIDTH(wp) - col)
        fdc = W_WIDTH(wp) - col;
    if (fdc > 0)
    {
        fill_foldcolumn(buf, wp, TRUE, lnum);
#ifdef FEAT_RIGHTLEFT
        if (wp->w_p_rl)
        {
            int         i;

            copy_text_attr(off + W_WIDTH(wp) - fdc - col, buf, fdc,
                                                             hl_attr(HLF_FC));
            /* reverse the fold column */
            for (i = 0; i < fdc; ++i)
                ScreenLines[off + W_WIDTH(wp) - i - 1 - col] = buf[i];
        }
        else
#endif
            copy_text_attr(off + col, buf, fdc, hl_attr(HLF_FC));
        col += fdc;
    }

#ifdef FEAT_RIGHTLEFT
# define RL_MEMSET(p, v, l)  if (wp->w_p_rl) \
                                for (ri = 0; ri < l; ++ri) \
                                   ScreenAttrs[off + (W_WIDTH(wp) - (p) - (l)) + ri] = v; \
                             else \
                                for (ri = 0; ri < l; ++ri) \
                                   ScreenAttrs[off + (p) + ri] = v
#else
# define RL_MEMSET(p, v, l)   for (ri = 0; ri < l; ++ri) \
                                 ScreenAttrs[off + (p) + ri] = v
#endif

    /* Set all attributes of the 'number' column and the text */
    RL_MEMSET(col, hl_attr(HLF_FL), W_WIDTH(wp) - col);

#ifdef FEAT_SIGNS
    /* If signs are being displayed, add two spaces. */
    if (draw_signcolumn(wp))
    {
        len = W_WIDTH(wp) - col;
        if (len > 0)
        {
            if (len > 2)
                len = 2;
# ifdef FEAT_RIGHTLEFT
            if (wp->w_p_rl)
                /* the line number isn't reversed */
                copy_text_attr(off + W_WIDTH(wp) - len - col,
                                        (char_u *)"  ", len, hl_attr(HLF_FL));
            else
# endif
                copy_text_attr(off + col, (char_u *)"  ", len, hl_attr(HLF_FL));
            col += len;
        }
    }
#endif

    /*
     * 3. Add the 'number' column
     */
    if (wp->w_p_nu)
    {
        len = W_WIDTH(wp) - col;
        if (len > 0)
        {
            int     w = number_width(wp);

            if (len > w + 1)
                len = w + 1;
            sprintf((char *)buf, "%*ld ", w, (long)lnum);
#ifdef FEAT_RIGHTLEFT
            if (wp->w_p_rl)
                /* the line number isn't reversed */
                copy_text_attr(off + W_WIDTH(wp) - len - col, buf, len,
                                                             hl_attr(HLF_FL));
            else
#endif
                copy_text_attr(off + col, buf, len, hl_attr(HLF_FL));
            col += len;
        }
    }

    /*
     * 4. Compose the folded-line string with 'foldtext', if set.
     */
    text = get_foldtext(wp, lnum, lnume, foldinfo, buf);

    txtcol = col;       /* remember where text starts */

    /*
     * 5. move the text to current_ScreenLine.  Fill up with "fill_fold".
     *    Right-left text is put in columns 0 - number-col, normal text is put
     *    in columns number-col - window-width.
     */
#ifdef FEAT_MBYTE
    if (has_mbyte)
    {
        int     cells;
        int     u8c, u8cc[MAX_MCO];
        int     i;
        int     idx;
        int     c_len;
        char_u  *p;
# ifdef FEAT_ARABIC
        int     prev_c = 0;             /* previous Arabic character */
        int     prev_c1 = 0;            /* first composing char for prev_c */
# endif

# ifdef FEAT_RIGHTLEFT
        if (wp->w_p_rl)
            idx = off;
        else
# endif
            idx = off + col;

        /* Store multibyte characters in ScreenLines[] et al. correctly. */
        for (p = text; *p != NUL; )
        {
            cells = (*mb_ptr2cells)(p);
            c_len = (*mb_ptr2len)(p);
            if (col + cells > W_WIDTH(wp)
# ifdef FEAT_RIGHTLEFT
                    - (wp->w_p_rl ? col : 0)
# endif
                    )
                break;
            ScreenLines[idx] = *p;
            if (enc_utf8)
            {
                u8c = utfc_ptr2char(p, u8cc);
                if (*p < 0x80 && u8cc[0] == 0)
                {
                    ScreenLinesUC[idx] = 0;
#ifdef FEAT_ARABIC
                    prev_c = u8c;
#endif
                }
                else
                {
#ifdef FEAT_ARABIC
                    if (p_arshape && !p_tbidi && ARABIC_CHAR(u8c))
                    {
                        /* Do Arabic shaping. */
                        int     pc, pc1, nc;
                        int     pcc[MAX_MCO];
                        int     firstbyte = *p;

                        /* The idea of what is the previous and next
                         * character depends on 'rightleft'. */
                        if (wp->w_p_rl)
                        {
                            pc = prev_c;
                            pc1 = prev_c1;
                            nc = utf_ptr2char(p + c_len);
                            prev_c1 = u8cc[0];
                        }
                        else
                        {
                            pc = utfc_ptr2char(p + c_len, pcc);
                            nc = prev_c;
                            pc1 = pcc[0];
                        }
                        prev_c = u8c;

                        u8c = arabic_shape(u8c, &firstbyte, &u8cc[0],
                                                                 pc, pc1, nc);
                        ScreenLines[idx] = firstbyte;
                    }
                    else
                        prev_c = u8c;
#endif
                    /* Non-BMP character: display as ? or fullwidth ?. */
#ifdef UNICODE16
                    if (u8c >= 0x10000)
                        ScreenLinesUC[idx] = (cells == 2) ? 0xff1f : (int)'?';
                    else
#endif
                        ScreenLinesUC[idx] = u8c;
                    for (i = 0; i < Screen_mco; ++i)
                    {
                        ScreenLinesC[i][idx] = u8cc[i];
                        if (u8cc[i] == 0)
                            break;
                    }
                }
                if (cells > 1)
                    ScreenLines[idx + 1] = 0;
            }
            else if (cells > 1)     /* double-byte character */
            {
                if (enc_dbcs == DBCS_JPNU && *p == 0x8e)
                    ScreenLines2[idx] = p[1];
                else
                    ScreenLines[idx + 1] = p[1];
            }
            col += cells;
            idx += cells;
            p += c_len;
        }
    }
    else
#endif
    {
        len = (int)STRLEN(text);
        if (len > W_WIDTH(wp) - col)
            len = W_WIDTH(wp) - col;
        if (len > 0)
        {
#ifdef FEAT_RIGHTLEFT
            if (wp->w_p_rl)
                STRNCPY(current_ScreenLine, text, len);
            else
#endif
                STRNCPY(current_ScreenLine + col, text, len);
            col += len;
        }
    }

    /* Fill the rest of the line with the fold filler */
#ifdef FEAT_RIGHTLEFT
    if (wp->w_p_rl)
        col -= txtcol;
#endif
    while (col < W_WIDTH(wp)
#ifdef FEAT_RIGHTLEFT
                    - (wp->w_p_rl ? txtcol : 0)
#endif
            )
    {
#ifdef FEAT_MBYTE
        if (enc_utf8)
        {
            if (fill_fold >= 0x80)
            {
                ScreenLinesUC[off + col] = fill_fold;
                ScreenLinesC[0][off + col] = 0;
            }
            else
                ScreenLinesUC[off + col] = 0;
        }
#endif
        ScreenLines[off + col++] = fill_fold;
    }

    if (text != buf)
        vim_free(text);

    /*
     * 6. set highlighting for the Visual area an other text.
     * If all folded lines are in the Visual area, highlight the line.
     */
#ifdef FEAT_VISUAL
    if (VIsual_active && wp->w_buffer == curwin->w_buffer)
    {
        if (ltoreq(curwin->w_cursor, VIsual))
        {
            /* Visual is after curwin->w_cursor */
            top = &curwin->w_cursor;
            bot = &VIsual;
        }
        else
        {
            /* Visual is before curwin->w_cursor */
            top = &VIsual;
            bot = &curwin->w_cursor;
        }
        if (lnum >= top->lnum
                && lnume <= bot->lnum
                && (VIsual_mode != 'v'
                    || ((lnum > top->lnum
                            || (lnum == top->lnum
                                && top->col == 0))
                        && (lnume < bot->lnum
                            || (lnume == bot->lnum
                                && (bot->col - (*p_sel == 'e'))
                >= STRLEN(ml_get_buf(wp->w_buffer, lnume, FALSE)))))))
        {
            if (VIsual_mode == Ctrl_V)
            {
                /* Visual block mode: highlight the chars part of the block */
                if (wp->w_old_cursor_fcol + txtcol < (colnr_T)W_WIDTH(wp))
                {
                    if (wp->w_old_cursor_lcol + txtcol < (colnr_T)W_WIDTH(wp))
                        len = wp->w_old_cursor_lcol;
                    else
                        len = W_WIDTH(wp) - txtcol;
                    RL_MEMSET(wp->w_old_cursor_fcol + txtcol, hl_attr(HLF_V),
                                            len - (int)wp->w_old_cursor_fcol);
                }
            }
            else
            {
                /* Set all attributes of the text */
                RL_MEMSET(txtcol, hl_attr(HLF_V), W_WIDTH(wp) - txtcol);
            }
        }
    }
#endif

#ifdef FEAT_SYN_HL
    /* Show 'cursorcolumn' in the fold line. */
    if (wp->w_p_cuc)
    {
        txtcol += wp->w_virtcol;
        if (wp->w_p_wrap)
            txtcol -= wp->w_skipcol;
        else
            txtcol -= wp->w_leftcol;
        if (txtcol >= 0 && txtcol < W_WIDTH(wp))
            ScreenAttrs[off + txtcol] = hl_combine_attr(
                                 ScreenAttrs[off + txtcol], hl_attr(HLF_CUC));
    }
#endif

    SCREEN_LINE(row + W_WINROW(wp), W_WINCOL(wp), (int)W_WIDTH(wp),
                                                     (int)W_WIDTH(wp), FALSE);

    /*
     * Update w_cline_height and w_cline_folded if the cursor line was
     * updated (saves a call to plines() later).
     */
    if (wp == curwin
            && lnum <= curwin->w_cursor.lnum
            && lnume >= curwin->w_cursor.lnum)
    {
        curwin->w_cline_row = row;
        curwin->w_cline_height = 1;
        curwin->w_cline_folded = TRUE;
        curwin->w_valid |= (VALID_CHEIGHT|VALID_CROW);
    }
}

/*
 * Copy "buf[len]" to ScreenLines["off"] and set attributes to "attr".
 */
    static void
copy_text_attr(off, buf, len, attr)
    int         off;
    char_u      *buf;
    int         len;
    int         attr;
{
    int         i;

    mch_memmove(ScreenLines + off, buf, (size_t)len);
# ifdef FEAT_MBYTE
    if (enc_utf8)
        vim_memset(ScreenLinesUC + off, 0, sizeof(u8char_T) * (size_t)len);
# endif
    for (i = 0; i < len; ++i)
        ScreenAttrs[off + i] = attr;
}

/*
 * Fill the foldcolumn at "p" for window "wp".
 * Only to be called when 'foldcolumn' > 0.
 */
    static void
fill_foldcolumn(p, wp, closed, lnum)
    char_u      *p;
    win_T       *wp;
    int         closed;         /* TRUE of FALSE */
    linenr_T    lnum;           /* current line number */
{
    int         i = 0;
    int         level;
    int         first_level;
    int         empty;

    /* Init to all spaces. */
    copy_spaces(p, (size_t)wp->w_p_fdc);

    level = win_foldinfo.fi_level;
    if (level > 0)
    {
        /* If there is only one column put more info in it. */
        empty = (wp->w_p_fdc == 1) ? 0 : 1;

        /* If the column is too narrow, we start at the lowest level that
         * fits and use numbers to indicated the depth. */
        first_level = level - wp->w_p_fdc - closed + 1 + empty;
        if (first_level < 1)
            first_level = 1;

        for (i = 0; i + empty < wp->w_p_fdc; ++i)
        {
            if (win_foldinfo.fi_lnum == lnum
                              && first_level + i >= win_foldinfo.fi_low_level)
                p[i] = '-';
            else if (first_level == 1)
                p[i] = '|';
            else if (first_level + i <= 9)
                p[i] = '0' + first_level + i;
            else
                p[i] = '>';
            if (first_level + i == level)
                break;
        }
    }
    if (closed)
        p[i >= wp->w_p_fdc ? i - 1 : i] = '+';
}
#endif /* FEAT_FOLDING */

/*
 * Display line "lnum" of window 'wp' on the screen.
 * Start at row "startrow", stop when "endrow" is reached.
 * wp->w_virtcol needs to be valid.
 *
 * Return the number of last row the line occupies.
 */
/* ARGSUSED */
    static int
win_line(wp, lnum, startrow, endrow, nochange)
    win_T       *wp;
    linenr_T    lnum;
    int         startrow;
    int         endrow;
    int         nochange;               /* not updating for changed text */
{
    int         col;                    /* visual column on screen */
    unsigned    off;                    /* offset in ScreenLines/ScreenAttrs */
    int         c = 0;                  /* init for GCC */
    long        vcol = 0;               /* virtual column (for tabs) */
    long        vcol_prev = -1;         /* "vcol" of previous character */
    char_u      *line;                  /* current line */
    char_u      *ptr;                   /* current position in "line" */
    int         row;                    /* row in the window, excl w_winrow */
    int         screen_row;             /* row on the screen, incl w_winrow */

    char_u      extra[18];              /* "%ld" and 'fdc' must fit in here */
    int         n_extra = 0;            /* number of extra chars */
    char_u      *p_extra = NULL;        /* string of extra chars, plus NUL */
    int         c_extra = NUL;          /* extra chars, all the same */
    int         extra_attr = 0;         /* attributes when n_extra != 0 */
    static char_u *at_end_str = (char_u *)""; /* used for p_extra when
                                           displaying lcs_eol at end-of-line */
    int         lcs_eol_one = lcs_eol;  /* lcs_eol until it's been used */
    int         lcs_prec_todo = lcs_prec;   /* lcs_prec until it's been used */

    /* saved "extra" items for when draw_state becomes WL_LINE (again) */
    int         saved_n_extra = 0;
    char_u      *saved_p_extra = NULL;
    int         saved_c_extra = 0;
    int         saved_char_attr = 0;

    int         n_attr = 0;             /* chars with special attr */
    int         saved_attr2 = 0;        /* char_attr saved for n_attr */
    int         n_attr3 = 0;            /* chars with overruling special attr */
    int         saved_attr3 = 0;        /* char_attr saved for n_attr3 */

    int         n_skip = 0;             /* nr of chars to skip for 'nowrap' */

    int         fromcol, tocol;         /* start/end of inverting */
    int         fromcol_prev = -2;      /* start of inverting after cursor */
    int         noinvcur = FALSE;       /* don't invert the cursor */
#ifdef FEAT_VISUAL
    pos_T       *top, *bot;
    int         lnum_in_visual_area = FALSE;
#endif
    pos_T       pos;
    long        v;

    int         char_attr = 0;          /* attributes for next character */
    int         attr_pri = FALSE;       /* char_attr has priority */
    int         area_highlighting = FALSE; /* Visual or incsearch highlighting
                                              in this line */
    int         attr = 0;               /* attributes for area highlighting */
    int         area_attr = 0;          /* attributes desired by highlighting */
    int         search_attr = 0;        /* attributes desired by 'hlsearch' */
#ifdef FEAT_SYN_HL
    int         vcol_save_attr = 0;     /* saved attr for 'cursorcolumn' */
    int         syntax_attr = 0;        /* attributes desired by syntax */
    int         has_syntax = FALSE;     /* this buffer has syntax highl. */
    int         save_did_emsg;
    int         eol_hl_off = 0;         /* 1 if highlighted char after EOL */
#endif
#ifdef FEAT_SPELL
    int         has_spell = FALSE;      /* this buffer has spell checking */
# define SPWORDLEN 150
    char_u      nextline[SPWORDLEN * 2];/* text with start of the next line */
    int         nextlinecol = 0;        /* column where nextline[] starts */
    int         nextline_idx = 0;       /* index in nextline[] where next line
                                           starts */
    int         spell_attr = 0;         /* attributes desired by spelling */
    int         word_end = 0;           /* last byte with same spell_attr */
    static linenr_T  checked_lnum = 0;  /* line number for "checked_col" */
    static int  checked_col = 0;        /* column in "checked_lnum" up to which
                                         * there are no spell errors */
    static int  cap_col = -1;           /* column to check for Cap word */
    static linenr_T capcol_lnum = 0;    /* line number where "cap_col" used */
    int         cur_checked_col = 0;    /* checked column for current line */
#endif
    int         extra_check;            /* has syntax or linebreak */
#ifdef FEAT_MBYTE
    int         multi_attr = 0;         /* attributes desired by multibyte */
    int         mb_l = 1;               /* multi-byte byte length */
    int         mb_c = 0;               /* decoded multi-byte character */
    int         mb_utf8 = FALSE;        /* screen char is UTF-8 char */
    int         u8cc[MAX_MCO];          /* composing UTF-8 chars */
#endif
#ifdef FEAT_DIFF
    int         filler_lines;           /* nr of filler lines to be drawn */
    int         filler_todo;            /* nr of filler lines still to do + 1 */
    hlf_T       diff_hlf = (hlf_T)0;    /* type of diff highlighting */
    int         change_start = MAXCOL;  /* first col of changed area */
    int         change_end = -1;        /* last col of changed area */
#endif
    colnr_T     trailcol = MAXCOL;      /* start of trailing spaces */
#ifdef FEAT_LINEBREAK
    int         need_showbreak = FALSE;
#endif
#if defined(FEAT_SIGNS) || (defined(FEAT_QUICKFIX) && defined(FEAT_WINDOWS)) \
        || defined(FEAT_SYN_HL) || defined(FEAT_DIFF)
# define LINE_ATTR
    int         line_attr = 0;          /* attribute for the whole line */
#endif
#ifdef FEAT_SEARCH_EXTRA
    matchitem_T *cur;                   /* points to the match list */
    match_T     *shl;                   /* points to search_hl or a match */
    int         shl_flag;               /* flag to indicate whether search_hl
                                           has been processed or not */
    int         prevcol_hl_flag;        /* flag to indicate whether prevcol
                                           equals startcol of search_hl or one
                                           of the matches */
#endif
#ifdef FEAT_ARABIC
    int         prev_c = 0;             /* previous Arabic character */
    int         prev_c1 = 0;            /* first composing char for prev_c */
#endif
#if defined(LINE_ATTR)
    int         did_line_attr = 0;
#endif

    /* draw_state: items that are drawn in sequence: */
#define WL_START        0               /* nothing done yet */
#ifdef FEAT_CMDWIN
# define WL_CMDLINE     WL_START + 1    /* cmdline window column */
#else
# define WL_CMDLINE     WL_START
#endif
#ifdef FEAT_FOLDING
# define WL_FOLD        WL_CMDLINE + 1  /* 'foldcolumn' */
#else
# define WL_FOLD        WL_CMDLINE
#endif
#ifdef FEAT_SIGNS
# define WL_SIGN        WL_FOLD + 1     /* column for signs */
#else
# define WL_SIGN        WL_FOLD         /* column for signs */
#endif
#define WL_NR           WL_SIGN + 1     /* line number */
#if defined(FEAT_LINEBREAK) || defined(FEAT_DIFF)
# define WL_SBR         WL_NR + 1       /* 'showbreak' or 'diff' */
#else
# define WL_SBR         WL_NR
#endif
#define WL_LINE         WL_SBR + 1      /* text in the line */
    int         draw_state = WL_START;  /* what to draw next */
#if defined(FEAT_XIM) && defined(FEAT_GUI_GTK)
    int         feedback_col = 0;
    int         feedback_old_attr = -1;
#endif


    if (startrow > endrow)              /* past the end already! */
        return startrow;

    row = startrow;
    screen_row = row + W_WINROW(wp);

    /*
     * To speed up the loop below, set extra_check when there is linebreak,
     * trailing white space and/or syntax processing to be done.
     */
#ifdef FEAT_LINEBREAK
    extra_check = wp->w_p_lbr;
#else
    extra_check = 0;
#endif
#ifdef FEAT_SYN_HL
    if (syntax_present(wp->w_buffer) && !wp->w_buffer->b_syn_error)
    {
        /* Prepare for syntax highlighting in this line.  When there is an
         * error, stop syntax highlighting. */
        save_did_emsg = did_emsg;
        did_emsg = FALSE;
        syntax_start(wp, lnum);
        if (did_emsg)
            wp->w_buffer->b_syn_error = TRUE;
        else
        {
            did_emsg = save_did_emsg;
            has_syntax = TRUE;
            extra_check = TRUE;
        }
    }
#endif

#ifdef FEAT_SPELL
    if (wp->w_p_spell
            && *wp->w_buffer->b_p_spl != NUL
            && wp->w_buffer->b_langp.ga_len > 0
            && *(char **)(wp->w_buffer->b_langp.ga_data) != NULL)
    {
        /* Prepare for spell checking. */
        has_spell = TRUE;
        extra_check = TRUE;

        /* Get the start of the next line, so that words that wrap to the next
         * line are found too: "et<line-break>al.".
         * Trick: skip a few chars for C/shell/Vim comments */
        nextline[SPWORDLEN] = NUL;
        if (lnum < wp->w_buffer->b_ml.ml_line_count)
        {
            line = ml_get_buf(wp->w_buffer, lnum + 1, FALSE);
            spell_cat_line(nextline + SPWORDLEN, line, SPWORDLEN);
        }

        /* When a word wrapped from the previous line the start of the current
         * line is valid. */
        if (lnum == checked_lnum)
            cur_checked_col = checked_col;
        checked_lnum = 0;

        /* When there was a sentence end in the previous line may require a
         * word starting with capital in this line.  In line 1 always check
         * the first word. */
        if (lnum != capcol_lnum)
            cap_col = -1;
        if (lnum == 1)
            cap_col = 0;
        capcol_lnum = 0;
    }
#endif

    /*
     * handle visual active in this window
     */
    fromcol = -10;
    tocol = MAXCOL;
#ifdef FEAT_VISUAL
    if (VIsual_active && wp->w_buffer == curwin->w_buffer)
    {
                                        /* Visual is after curwin->w_cursor */
        if (ltoreq(curwin->w_cursor, VIsual))
        {
            top = &curwin->w_cursor;
            bot = &VIsual;
        }
        else                            /* Visual is before curwin->w_cursor */
        {
            top = &VIsual;
            bot = &curwin->w_cursor;
        }
        lnum_in_visual_area = (lnum >= top->lnum && lnum <= bot->lnum);
        if (VIsual_mode == Ctrl_V)      /* block mode */
        {
            if (lnum_in_visual_area)
            {
                fromcol = wp->w_old_cursor_fcol;
                tocol = wp->w_old_cursor_lcol;
            }
        }
        else                            /* non-block mode */
        {
            if (lnum > top->lnum && lnum <= bot->lnum)
                fromcol = 0;
            else if (lnum == top->lnum)
            {
                if (VIsual_mode == 'V') /* linewise */
                    fromcol = 0;
                else
                {
                    getvvcol(wp, top, (colnr_T *)&fromcol, NULL, NULL);
                    if (gchar_pos(top) == NUL)
                        tocol = fromcol + 1;
                }
            }
            if (VIsual_mode != 'V' && lnum == bot->lnum)
            {
                if (*p_sel == 'e' && bot->col == 0
#ifdef FEAT_VIRTUALEDIT
                        && bot->coladd == 0
#endif
                   )
                {
                    fromcol = -10;
                    tocol = MAXCOL;
                }
                else if (bot->col == MAXCOL)
                    tocol = MAXCOL;
                else
                {
                    pos = *bot;
                    if (*p_sel == 'e')
                        getvvcol(wp, &pos, (colnr_T *)&tocol, NULL, NULL);
                    else
                    {
                        getvvcol(wp, &pos, NULL, NULL, (colnr_T *)&tocol);
                        ++tocol;
                    }
                }
            }
        }

#ifndef MSDOS
        /* Check if the character under the cursor should not be inverted */
        if (!highlight_match && lnum == curwin->w_cursor.lnum && wp == curwin
# ifdef FEAT_GUI
                && !gui.in_use
# endif
                )
            noinvcur = TRUE;
#endif

        /* if inverting in this line set area_highlighting */
        if (fromcol >= 0)
        {
            area_highlighting = TRUE;
            attr = hl_attr(HLF_V);
#if defined(FEAT_CLIPBOARD) && defined(FEAT_X11)
            if (clip_star.available && !clip_star.owned && clip_isautosel())
                attr = hl_attr(HLF_VNC);
#endif
        }
    }

    /*
     * handle 'incsearch' and ":s///c" highlighting
     */
    else
#endif /* FEAT_VISUAL */
        if (highlight_match
            && wp == curwin
            && lnum >= curwin->w_cursor.lnum
            && lnum <= curwin->w_cursor.lnum + search_match_lines)
    {
        if (lnum == curwin->w_cursor.lnum)
            getvcol(curwin, &(curwin->w_cursor),
                                             (colnr_T *)&fromcol, NULL, NULL);
        else
            fromcol = 0;
        if (lnum == curwin->w_cursor.lnum + search_match_lines)
        {
            pos.lnum = lnum;
            pos.col = search_match_endcol;
            getvcol(curwin, &pos, (colnr_T *)&tocol, NULL, NULL);
        }
        else
            tocol = MAXCOL;
        if (fromcol == tocol)           /* do at least one character */
            tocol = fromcol + 1;        /* happens when past end of line */
        area_highlighting = TRUE;
        attr = hl_attr(HLF_I);
    }

#ifdef FEAT_DIFF
    filler_lines = diff_check(wp, lnum);
    if (filler_lines < 0)
    {
        if (filler_lines == -1)
        {
            if (diff_find_change(wp, lnum, &change_start, &change_end))
                diff_hlf = HLF_ADD;     /* added line */
            else if (change_start == 0)
                diff_hlf = HLF_TXD;     /* changed text */
            else
                diff_hlf = HLF_CHD;     /* changed line */
        }
        else
            diff_hlf = HLF_ADD;         /* added line */
        filler_lines = 0;
        area_highlighting = TRUE;
    }
    if (lnum == wp->w_topline)
        filler_lines = wp->w_topfill;
    filler_todo = filler_lines;
#endif

#ifdef LINE_ATTR
# ifdef FEAT_SIGNS
    /* If this line has a sign with line highlighting set line_attr. */
    v = buf_getsigntype(wp->w_buffer, lnum, SIGN_LINEHL);
    if (v != 0)
        line_attr = sign_get_attr((int)v, TRUE);
# endif
# if defined(FEAT_QUICKFIX) && defined(FEAT_WINDOWS)
    /* Highlight the current line in the quickfix window. */
    if (bt_quickfix(wp->w_buffer) && qf_current_entry(wp) == lnum)
        line_attr = hl_attr(HLF_L);
# endif
    if (line_attr != 0)
        area_highlighting = TRUE;
#endif

    line = ml_get_buf(wp->w_buffer, lnum, FALSE);
    ptr = line;

#ifdef FEAT_SPELL
    if (has_spell)
    {
        /* For checking first word with a capital skip white space. */
        if (cap_col == 0)
            cap_col = (int)(skipwhite(line) - line);

        /* To be able to spell-check over line boundaries copy the end of the
         * current line into nextline[].  Above the start of the next line was
         * copied to nextline[SPWORDLEN]. */
        if (nextline[SPWORDLEN] == NUL)
        {
            /* No next line or it is empty. */
            nextlinecol = MAXCOL;
            nextline_idx = 0;
        }
        else
        {
            v = (long)STRLEN(line);
            if (v < SPWORDLEN)
            {
                /* Short line, use it completely and append the start of the
                 * next line. */
                nextlinecol = 0;
                mch_memmove(nextline, line, (size_t)v);
                STRMOVE(nextline + v, nextline + SPWORDLEN);
                nextline_idx = v + 1;
            }
            else
            {
                /* Long line, use only the last SPWORDLEN bytes. */
                nextlinecol = v - SPWORDLEN;
                mch_memmove(nextline, line + nextlinecol, SPWORDLEN);
                nextline_idx = SPWORDLEN + 1;
            }
        }
    }
#endif

    /* find start of trailing whitespace */
    if (wp->w_p_list && lcs_trail)
    {
        trailcol = (colnr_T)STRLEN(ptr);
        while (trailcol > (colnr_T)0 && vim_iswhite(ptr[trailcol - 1]))
            --trailcol;
        trailcol += (colnr_T) (ptr - line);
        extra_check = TRUE;
    }

    /*
     * 'nowrap' or 'wrap' and a single line that doesn't fit: Advance to the
     * first character to be displayed.
     */
    if (wp->w_p_wrap)
        v = wp->w_skipcol;
    else
        v = wp->w_leftcol;
    if (v > 0)
    {
#ifdef FEAT_MBYTE
        char_u  *prev_ptr = ptr;
#endif
        while (vcol < v && *ptr != NUL)
        {
            c = win_lbr_chartabsize(wp, ptr, (colnr_T)vcol, NULL);
            vcol += c;
#ifdef FEAT_MBYTE
            prev_ptr = ptr;
#endif
            mb_ptr_adv(ptr);
        }

#ifdef FEAT_VIRTUALEDIT
        /* When 'virtualedit' is set the end of the line may be before the
         * start of the displayed part. */
        if (vcol < v && *ptr == NUL && virtual_active())
            vcol = v;
#endif

        /* Handle a character that's not completely on the screen: Put ptr at
         * that character but skip the first few screen characters. */
        if (vcol > v)
        {
            vcol -= c;
#ifdef FEAT_MBYTE
            ptr = prev_ptr;
#else
            --ptr;
#endif
            n_skip = v - vcol;
        }

        /*
         * Adjust for when the inverted text is before the screen,
         * and when the start of the inverted text is before the screen.
         */
        if (tocol <= vcol)
            fromcol = 0;
        else if (fromcol >= 0 && fromcol < vcol)
            fromcol = vcol;

#ifdef FEAT_LINEBREAK
        /* When w_skipcol is non-zero, first line needs 'showbreak' */
        if (wp->w_p_wrap)
            need_showbreak = TRUE;
#endif
#ifdef FEAT_SPELL
        /* When spell checking a word we need to figure out the start of the
         * word and if it's badly spelled or not. */
        if (has_spell)
        {
            int         len;
            colnr_T     linecol = (colnr_T)(ptr - line);
            hlf_T       spell_hlf = HLF_COUNT;

            pos = wp->w_cursor;
            wp->w_cursor.lnum = lnum;
            wp->w_cursor.col = linecol;
            len = spell_move_to(wp, FORWARD, TRUE, TRUE, &spell_hlf);

            /* spell_move_to() may call ml_get() and make "line" invalid */
            line = ml_get_buf(wp->w_buffer, lnum, FALSE);
            ptr = line + linecol;

            if (len == 0 || (int)wp->w_cursor.col > ptr - line)
            {
                /* no bad word found at line start, don't check until end of a
                 * word */
                spell_hlf = HLF_COUNT;
                word_end = (int)(spell_to_word_end(ptr, wp->w_buffer)
                                                                  - line + 1);
            }
            else
            {
                /* bad word found, use attributes until end of word */
                word_end = wp->w_cursor.col + len + 1;

                /* Turn index into actual attributes. */
                if (spell_hlf != HLF_COUNT)
                    spell_attr = highlight_attr[spell_hlf];
            }
            wp->w_cursor = pos;

# ifdef FEAT_SYN_HL
            /* Need to restart syntax highlighting for this line. */
            if (has_syntax)
                syntax_start(wp, lnum);
# endif
        }
#endif
    }

    /*
     * Correct highlighting for cursor that can't be disabled.
     * Avoids having to check this for each character.
     */
    if (fromcol >= 0)
    {
        if (noinvcur)
        {
            if ((colnr_T)fromcol == wp->w_virtcol)
            {
                /* highlighting starts at cursor, let it start just after the
                 * cursor */
                fromcol_prev = fromcol;
                fromcol = -1;
            }
            else if ((colnr_T)fromcol < wp->w_virtcol)
                /* restart highlighting after the cursor */
                fromcol_prev = wp->w_virtcol;
        }
        if (fromcol >= tocol)
            fromcol = -1;
    }

#ifdef FEAT_SEARCH_EXTRA
    /*
     * Handle highlighting the last used search pattern and matches.
     * Do this for both search_hl and the match list.
     */
    cur = wp->w_match_head;
    shl_flag = FALSE;
    while (cur != NULL || shl_flag == FALSE)
    {
        if (shl_flag == FALSE)
        {
            shl = &search_hl;
            shl_flag = TRUE;
        }
        else
            shl = &cur->hl;
        shl->startcol = MAXCOL;
        shl->endcol = MAXCOL;
        shl->attr_cur = 0;
        if (shl->rm.regprog != NULL)
        {
            v = (long)(ptr - line);
            next_search_hl(wp, shl, lnum, (colnr_T)v);

            /* Need to get the line again, a multi-line regexp may have made it
             * invalid. */
            line = ml_get_buf(wp->w_buffer, lnum, FALSE);
            ptr = line + v;

            if (shl->lnum != 0 && shl->lnum <= lnum)
            {
                if (shl->lnum == lnum)
                    shl->startcol = shl->rm.startpos[0].col;
                else
                    shl->startcol = 0;
                if (lnum == shl->lnum + shl->rm.endpos[0].lnum
                                                  - shl->rm.startpos[0].lnum)
                    shl->endcol = shl->rm.endpos[0].col;
                else
                    shl->endcol = MAXCOL;
                /* Highlight one character for an empty match. */
                if (shl->startcol == shl->endcol)
                {
#ifdef FEAT_MBYTE
                    if (has_mbyte && line[shl->endcol] != NUL)
                        shl->endcol += (*mb_ptr2len)(line + shl->endcol);
                    else
#endif
                        ++shl->endcol;
                }
                if ((long)shl->startcol < v)  /* match at leftcol */
                {
                    shl->attr_cur = shl->attr;
                    search_attr = shl->attr;
                }
                area_highlighting = TRUE;
            }
        }
        if (shl != &search_hl && cur != NULL)
            cur = cur->next;
    }
#endif

#ifdef FEAT_SYN_HL
    /* Cursor line highlighting for 'cursorline'.  Not when Visual mode is
     * active, because it's not clear what is selected then. */
    if (wp->w_p_cul && lnum == wp->w_cursor.lnum && !VIsual_active)
    {
        line_attr = hl_attr(HLF_CUL);
        area_highlighting = TRUE;
    }
#endif

    off = (unsigned)(current_ScreenLine - ScreenLines);
    col = 0;
#ifdef FEAT_RIGHTLEFT
    if (wp->w_p_rl)
    {
        /* Rightleft window: process the text in the normal direction, but put
         * it in current_ScreenLine[] from right to left.  Start at the
         * rightmost column of the window. */
        col = W_WIDTH(wp) - 1;
        off += col;
    }
#endif

    /*
     * Repeat for the whole displayed line.
     */
    for (;;)
    {
        /* Skip this quickly when working on the text. */
        if (draw_state != WL_LINE)
        {
#ifdef FEAT_CMDWIN
            if (draw_state == WL_CMDLINE - 1 && n_extra == 0)
            {
                draw_state = WL_CMDLINE;
                if (cmdwin_type != 0 && wp == curwin)
                {
                    /* Draw the cmdline character. */
                    n_extra = 1;
                    c_extra = cmdwin_type;
                    char_attr = hl_attr(HLF_AT);
                }
            }
#endif

#ifdef FEAT_FOLDING
            if (draw_state == WL_FOLD - 1 && n_extra == 0)
            {
                draw_state = WL_FOLD;
                if (wp->w_p_fdc > 0)
                {
                    /* Draw the 'foldcolumn'. */
                    fill_foldcolumn(extra, wp, FALSE, lnum);
                    n_extra = wp->w_p_fdc;
                    p_extra = extra;
                    p_extra[n_extra] = NUL;
                    c_extra = NUL;
                    char_attr = hl_attr(HLF_FC);
                }
            }
#endif

#ifdef FEAT_SIGNS
            if (draw_state == WL_SIGN - 1 && n_extra == 0)
            {
                draw_state = WL_SIGN;
                /* Show the sign column when there are any signs in this
                 * buffer or when using Netbeans. */
                if (draw_signcolumn(wp)
# ifdef FEAT_DIFF
                        && filler_todo <= 0
# endif
                   )
                {
                    int_u       text_sign;
# ifdef FEAT_SIGN_ICONS
                    int_u       icon_sign;
# endif

                    /* Draw two cells with the sign value or blank. */
                    c_extra = ' ';
                    char_attr = hl_attr(HLF_SC);
                    n_extra = 2;

                    if (row == startrow)
                    {
                        text_sign = buf_getsigntype(wp->w_buffer, lnum,
                                                                   SIGN_TEXT);
# ifdef FEAT_SIGN_ICONS
                        icon_sign = buf_getsigntype(wp->w_buffer, lnum,
                                                                   SIGN_ICON);
                        if (gui.in_use && icon_sign != 0)
                        {
                            /* Use the image in this position. */
                            c_extra = SIGN_BYTE;
#  ifdef FEAT_NETBEANS_INTG
                            if (buf_signcount(wp->w_buffer, lnum) > 1)
                                c_extra = MULTISIGN_BYTE;
#  endif
                            char_attr = icon_sign;
                        }
                        else
# endif
                            if (text_sign != 0)
                        {
                            p_extra = sign_get_text(text_sign);
                            if (p_extra != NULL)
                            {
                                c_extra = NUL;
                                n_extra = (int)STRLEN(p_extra);
                            }
                            char_attr = sign_get_attr(text_sign, FALSE);
                        }
                    }
                }
            }
#endif

            if (draw_state == WL_NR - 1 && n_extra == 0)
            {
                draw_state = WL_NR;
                /* Display the line number.  After the first fill with blanks
                 * when the 'n' flag isn't in 'cpo' */
                if (wp->w_p_nu
                        && (row == startrow
#ifdef FEAT_DIFF
                            + filler_lines
#endif
                            || vim_strchr(p_cpo, CPO_NUMCOL) == NULL))
                {
                    /* Draw the line number (empty space after wrapping). */
                    if (row == startrow
#ifdef FEAT_DIFF
                            + filler_lines
#endif
                            )
                    {
                        sprintf((char *)extra, "%*ld ",
                                                number_width(wp), (long)lnum);
                        if (wp->w_skipcol > 0)
                            for (p_extra = extra; *p_extra == ' '; ++p_extra)
                                *p_extra = '-';
#ifdef FEAT_RIGHTLEFT
                        if (wp->w_p_rl)             /* reverse line numbers */
                            rl_mirror(extra);
#endif
                        p_extra = extra;
                        c_extra = NUL;
                    }
                    else
                        c_extra = ' ';
                    n_extra = number_width(wp) + 1;
                    char_attr = hl_attr(HLF_N);
#ifdef FEAT_SYN_HL
                    /* When 'cursorline' is set highlight the line number of
                     * the current line differently. */
                    if (wp->w_p_cul && lnum == wp->w_cursor.lnum)
                        char_attr = hl_combine_attr(hl_attr(HLF_CUL), char_attr);
#endif
                }
            }

#if defined(FEAT_LINEBREAK) || defined(FEAT_DIFF)
            if (draw_state == WL_SBR - 1 && n_extra == 0)
            {
                draw_state = WL_SBR;
# ifdef FEAT_DIFF
                if (filler_todo > 0)
                {
                    /* Draw "deleted" diff line(s). */
                    if (char2cells(fill_diff) > 1)
                        c_extra = '-';
                    else
                        c_extra = fill_diff;
#  ifdef FEAT_RIGHTLEFT
                    if (wp->w_p_rl)
                        n_extra = col + 1;
                    else
#  endif
                        n_extra = W_WIDTH(wp) - col;
                    char_attr = hl_attr(HLF_DED);
                }
# endif
# ifdef FEAT_LINEBREAK
                if (*p_sbr != NUL && need_showbreak)
                {
                    /* Draw 'showbreak' at the start of each broken line. */
                    p_extra = p_sbr;
                    c_extra = NUL;
                    n_extra = (int)STRLEN(p_sbr);
                    char_attr = hl_attr(HLF_AT);
                    need_showbreak = FALSE;
                    /* Correct end of highlighted area for 'showbreak',
                     * required when 'linebreak' is also set. */
                    if (tocol == vcol)
                        tocol += n_extra;
                }
# endif
            }
#endif

            if (draw_state == WL_LINE - 1 && n_extra == 0)
            {
                draw_state = WL_LINE;
                if (saved_n_extra)
                {
                    /* Continue item from end of wrapped line. */
                    n_extra = saved_n_extra;
                    c_extra = saved_c_extra;
                    p_extra = saved_p_extra;
                    char_attr = saved_char_attr;
                }
                else
                    char_attr = 0;
            }
        }

        /* When still displaying '$' of change command, stop at cursor */
        if (dollar_vcol != 0 && wp == curwin
                   && lnum == wp->w_cursor.lnum && vcol >= (long)wp->w_virtcol
#ifdef FEAT_DIFF
                                   && filler_todo <= 0
#endif
                )
        {
            SCREEN_LINE(screen_row, W_WINCOL(wp), col, -(int)W_WIDTH(wp),
                                                                  wp->w_p_rl);
            /* Pretend we have finished updating the window.  Except when
             * 'cursorcolumn' is set. */
#ifdef FEAT_SYN_HL
            if (wp->w_p_cuc)
                row = wp->w_cline_row + wp->w_cline_height;
            else
#endif
                row = wp->w_height;
            break;
        }

        if (draw_state == WL_LINE && area_highlighting)
        {
            /* handle Visual or match highlighting in this line */
            if (vcol == fromcol
#ifdef FEAT_MBYTE
                    || (has_mbyte && vcol + 1 == fromcol && n_extra == 0
                        && (*mb_ptr2cells)(ptr) > 1)
#endif
                    || ((int)vcol_prev == fromcol_prev
                        && vcol_prev < vcol     /* not at margin */
                        && vcol < tocol))
                area_attr = attr;               /* start highlighting */
            else if (area_attr != 0
                    && (vcol == tocol
                        || (noinvcur && (colnr_T)vcol == wp->w_virtcol)))
                area_attr = 0;                  /* stop highlighting */

#ifdef FEAT_SEARCH_EXTRA
            if (!n_extra)
            {
                /*
                 * Check for start/end of search pattern match.
                 * After end, check for start/end of next match.
                 * When another match, have to check for start again.
                 * Watch out for matching an empty string!
                 * Do this for 'search_hl' and the match list (ordered by
                 * priority).
                 */
                v = (long)(ptr - line);
                cur = wp->w_match_head;
                shl_flag = FALSE;
                while (cur != NULL || shl_flag == FALSE)
                {
                    if (shl_flag == FALSE
                            && ((cur != NULL
                                    && cur->priority > SEARCH_HL_PRIORITY)
                                || cur == NULL))
                    {
                        shl = &search_hl;
                        shl_flag = TRUE;
                    }
                    else
                        shl = &cur->hl;
                    while (shl->rm.regprog != NULL)
                    {
                        if (shl->startcol != MAXCOL
                                && v >= (long)shl->startcol
                                && v < (long)shl->endcol)
                        {
                            shl->attr_cur = shl->attr;
                        }
                        else if (v == (long)shl->endcol)
                        {
                            shl->attr_cur = 0;

                            next_search_hl(wp, shl, lnum, (colnr_T)v);

                            /* Need to get the line again, a multi-line regexp
                             * may have made it invalid. */
                            line = ml_get_buf(wp->w_buffer, lnum, FALSE);
                            ptr = line + v;

                            if (shl->lnum == lnum)
                            {
                                shl->startcol = shl->rm.startpos[0].col;
                                if (shl->rm.endpos[0].lnum == 0)
                                    shl->endcol = shl->rm.endpos[0].col;
                                else
                                    shl->endcol = MAXCOL;

                                if (shl->startcol == shl->endcol)
                                {
                                    /* highlight empty match, try again after
                                     * it */
#ifdef FEAT_MBYTE
                                    if (has_mbyte)
                                        shl->endcol += (*mb_ptr2len)(line
                                                               + shl->endcol);
                                    else
#endif
                                        ++shl->endcol;
                                }

                                /* Loop to check if the match starts at the
                                 * current position */
                                continue;
                            }
                        }
                        break;
                    }
                    if (shl != &search_hl && cur != NULL)
                        cur = cur->next;
                }

                /* Use attributes from match with highest priority among
                 * 'search_hl' and the match list. */
                search_attr = search_hl.attr_cur;
                cur = wp->w_match_head;
                shl_flag = FALSE;
                while (cur != NULL || shl_flag == FALSE)
                {
                    if (shl_flag == FALSE
                            && ((cur != NULL
                                    && cur->priority > SEARCH_HL_PRIORITY)
                                || cur == NULL))
                    {
                        shl = &search_hl;
                        shl_flag = TRUE;
                    }
                    else
                        shl = &cur->hl;
                    if (shl->attr_cur != 0)
                        search_attr = shl->attr_cur;
                    if (shl != &search_hl && cur != NULL)
                        cur = cur->next;
                }
            }
#endif

#ifdef FEAT_DIFF
            if (diff_hlf != (hlf_T)0)
            {
                if (diff_hlf == HLF_CHD && ptr - line >= change_start
                                                              && n_extra == 0)
                    diff_hlf = HLF_TXD;         /* changed text */
                if (diff_hlf == HLF_TXD && ptr - line > change_end
                                                              && n_extra == 0)
                    diff_hlf = HLF_CHD;         /* changed line */
                line_attr = hl_attr(diff_hlf);
            }
#endif

            /* Decide which of the highlight attributes to use. */
            attr_pri = TRUE;
            if (area_attr != 0)
                char_attr = area_attr;
            else if (search_attr != 0)
                char_attr = search_attr;
#ifdef LINE_ATTR
                /* Use line_attr when not in the Visual or 'incsearch' area
                 * (area_attr may be 0 when "noinvcur" is set). */
            else if (line_attr != 0 && ((fromcol == -10 && tocol == MAXCOL)
                                || vcol < fromcol || vcol_prev < fromcol_prev
                                || vcol >= tocol))
                char_attr = line_attr;
#endif
            else
            {
                attr_pri = FALSE;
#ifdef FEAT_SYN_HL
                if (has_syntax)
                    char_attr = syntax_attr;
                else
#endif
                    char_attr = 0;
            }
        }

        /*
         * Get the next character to put on the screen.
         */
        /*
         * The "p_extra" points to the extra stuff that is inserted to
         * represent special characters (non-printable stuff) and other
         * things.  When all characters are the same, c_extra is used.
         * "p_extra" must end in a NUL to avoid mb_ptr2len() reads past
         * "p_extra[n_extra]".
         * For the '$' of the 'list' option, n_extra == 1, p_extra == "".
         */
        if (n_extra > 0)
        {
            if (c_extra != NUL)
            {
                c = c_extra;
#ifdef FEAT_MBYTE
                mb_c = c;       /* doesn't handle non-utf-8 multi-byte! */
                if (enc_utf8 && (*mb_char2len)(c) > 1)
                {
                    mb_utf8 = TRUE;
                    u8cc[0] = 0;
                    c = 0xc0;
                }
                else
                    mb_utf8 = FALSE;
#endif
            }
            else
            {
                c = *p_extra;
#ifdef FEAT_MBYTE
                if (has_mbyte)
                {
                    mb_c = c;
                    if (enc_utf8)
                    {
                        /* If the UTF-8 character is more than one byte:
                         * Decode it into "mb_c". */
                        mb_l = (*mb_ptr2len)(p_extra);
                        mb_utf8 = FALSE;
                        if (mb_l > n_extra)
                            mb_l = 1;
                        else if (mb_l > 1)
                        {
                            mb_c = utfc_ptr2char(p_extra, u8cc);
                            mb_utf8 = TRUE;
                            c = 0xc0;
                        }
                    }
                    else
                    {
                        /* if this is a DBCS character, put it in "mb_c" */
                        mb_l = MB_BYTE2LEN(c);
                        if (mb_l >= n_extra)
                            mb_l = 1;
                        else if (mb_l > 1)
                            mb_c = (c << 8) + p_extra[1];
                    }
                    if (mb_l == 0)  /* at the NUL at end-of-line */
                        mb_l = 1;

                    /* If a double-width char doesn't fit display a '>' in the
                     * last column. */
                    if ((
# ifdef FEAT_RIGHTLEFT
                            wp->w_p_rl ? (col <= 0) :
# endif
                                    (col >= W_WIDTH(wp) - 1))
                            && (*mb_char2cells)(mb_c) == 2)
                    {
                        c = '>';
                        mb_c = c;
                        mb_l = 1;
                        mb_utf8 = FALSE;
                        multi_attr = hl_attr(HLF_AT);
                        /* put the pointer back to output the double-width
                         * character at the start of the next line. */
                        ++n_extra;
                        --p_extra;
                    }
                    else
                    {
                        n_extra -= mb_l - 1;
                        p_extra += mb_l - 1;
                    }
                }
#endif
                ++p_extra;
            }
            --n_extra;
        }
        else
        {
            /*
             * Get a character from the line itself.
             */
            c = *ptr;
#ifdef FEAT_MBYTE
            if (has_mbyte)
            {
                mb_c = c;
                if (enc_utf8)
                {
                    /* If the UTF-8 character is more than one byte: Decode it
                     * into "mb_c". */
                    mb_l = (*mb_ptr2len)(ptr);
                    mb_utf8 = FALSE;
                    if (mb_l > 1)
                    {
                        mb_c = utfc_ptr2char(ptr, u8cc);
                        /* Overlong encoded ASCII or ASCII with composing char
                         * is displayed normally, except a NUL. */
                        if (mb_c < 0x80)
                            c = mb_c;
                        mb_utf8 = TRUE;

                        /* At start of the line we can have a composing char.
                         * Draw it as a space with a composing char. */
                        if (utf_iscomposing(mb_c))
                        {
                            int i;

                            for (i = Screen_mco - 1; i > 0; --i)
                                u8cc[i] = u8cc[i - 1];
                            u8cc[0] = mb_c;
                            mb_c = ' ';
                        }
                    }

                    if ((mb_l == 1 && c >= 0x80)
                            || (mb_l >= 1 && mb_c == 0)
                            || (mb_l > 1 && (!vim_isprintc(mb_c)
# ifdef UNICODE16
                                                         || mb_c >= 0x10000
# endif
                                                         )))
                    {
                        /*
                         * Illegal UTF-8 byte: display as <xx>.
                         * Non-BMP character : display as ? or fullwidth ?.
                         */
# ifdef UNICODE16
                        if (mb_c < 0x10000)
# endif
                        {
                            transchar_hex(extra, mb_c);
# ifdef FEAT_RIGHTLEFT
                            if (wp->w_p_rl)             /* reverse */
                                rl_mirror(extra);
# endif
                        }
# ifdef UNICODE16
                        else if (utf_char2cells(mb_c) != 2)
                            STRCPY(extra, "?");
                        else
                            /* 0xff1f in UTF-8: full-width '?' */
                            STRCPY(extra, "\357\274\237");
# endif

                        p_extra = extra;
                        c = *p_extra;
                        mb_c = mb_ptr2char_adv(&p_extra);
                        mb_utf8 = (c >= 0x80);
                        n_extra = (int)STRLEN(p_extra);
                        c_extra = NUL;
                        if (area_attr == 0 && search_attr == 0)
                        {
                            n_attr = n_extra + 1;
                            extra_attr = hl_attr(HLF_8);
                            saved_attr2 = char_attr; /* save current attr */
                        }
                    }
                    else if (mb_l == 0)  /* at the NUL at end-of-line */
                        mb_l = 1;
#ifdef FEAT_ARABIC
                    else if (p_arshape && !p_tbidi && ARABIC_CHAR(mb_c))
                    {
                        /* Do Arabic shaping. */
                        int     pc, pc1, nc;
                        int     pcc[MAX_MCO];

                        /* The idea of what is the previous and next
                         * character depends on 'rightleft'. */
                        if (wp->w_p_rl)
                        {
                            pc = prev_c;
                            pc1 = prev_c1;
                            nc = utf_ptr2char(ptr + mb_l);
                            prev_c1 = u8cc[0];
                        }
                        else
                        {
                            pc = utfc_ptr2char(ptr + mb_l, pcc);
                            nc = prev_c;
                            pc1 = pcc[0];
                        }
                        prev_c = mb_c;

                        mb_c = arabic_shape(mb_c, &c, &u8cc[0], pc, pc1, nc);
                    }
                    else
                        prev_c = mb_c;
#endif
                }
                else    /* enc_dbcs */
                {
                    mb_l = MB_BYTE2LEN(c);
                    if (mb_l == 0)  /* at the NUL at end-of-line */
                        mb_l = 1;
                    else if (mb_l > 1)
                    {
                        /* We assume a second byte below 32 is illegal.
                         * Hopefully this is OK for all double-byte encodings!
                         */
                        if (ptr[1] >= 32)
                            mb_c = (c << 8) + ptr[1];
                        else
                        {
                            if (ptr[1] == NUL)
                            {
                                /* head byte at end of line */
                                mb_l = 1;
                                transchar_nonprint(extra, c);
                            }
                            else
                            {
                                /* illegal tail byte */
                                mb_l = 2;
                                STRCPY(extra, "XX");
                            }
                            p_extra = extra;
                            n_extra = (int)STRLEN(extra) - 1;
                            c_extra = NUL;
                            c = *p_extra++;
                            if (area_attr == 0 && search_attr == 0)
                            {
                                n_attr = n_extra + 1;
                                extra_attr = hl_attr(HLF_8);
                                saved_attr2 = char_attr; /* save current attr */
                            }
                            mb_c = c;
                        }
                    }
                }
                /* If a double-width char doesn't fit display a '>' in the
                 * last column; the character is displayed at the start of the
                 * next line. */
                if ((
# ifdef FEAT_RIGHTLEFT
                            wp->w_p_rl ? (col <= 0) :
# endif
                                (col >= W_WIDTH(wp) - 1))
                        && (*mb_char2cells)(mb_c) == 2)
                {
                    c = '>';
                    mb_c = c;
                    mb_utf8 = FALSE;
                    mb_l = 1;
                    multi_attr = hl_attr(HLF_AT);
                    /* Put pointer back so that the character will be
                     * displayed at the start of the next line. */
                    --ptr;
                }
                else if (*ptr != NUL)
                    ptr += mb_l - 1;

                /* If a double-width char doesn't fit at the left side display
                 * a '<' in the first column. */
                if (n_skip > 0 && mb_l > 1)
                {
                    n_extra = 1;
                    c_extra = '<';
                    c = ' ';
                    if (area_attr == 0 && search_attr == 0)
                    {
                        n_attr = n_extra + 1;
                        extra_attr = hl_attr(HLF_AT);
                        saved_attr2 = char_attr; /* save current attr */
                    }
                    mb_c = c;
                    mb_utf8 = FALSE;
                    mb_l = 1;
                }

            }
#endif
            ++ptr;

            /* 'list' : change char 160 to lcs_nbsp. */
            if (wp->w_p_list && (c == 160
#ifdef FEAT_MBYTE
                        || (mb_utf8 && mb_c == 160)
#endif
                        ) && lcs_nbsp)
            {
                c = lcs_nbsp;
                if (area_attr == 0 && search_attr == 0)
                {
                    n_attr = 1;
                    extra_attr = hl_attr(HLF_8);
                    saved_attr2 = char_attr; /* save current attr */
                }
#ifdef FEAT_MBYTE
                mb_c = c;
                if (enc_utf8 && (*mb_char2len)(c) > 1)
                {
                    mb_utf8 = TRUE;
                    u8cc[0] = 0;
                    c = 0xc0;
                }
                else
                    mb_utf8 = FALSE;
#endif
            }

            if (extra_check)
            {
#ifdef FEAT_SPELL
                int     can_spell = TRUE;
#endif

#ifdef FEAT_SYN_HL
                /* Get syntax attribute, unless still at the start of the line
                 * (double-wide char that doesn't fit). */
                v = (long)(ptr - line);
                if (has_syntax && v > 0)
                {
                    /* Get the syntax attribute for the character.  If there
                     * is an error, disable syntax highlighting. */
                    save_did_emsg = did_emsg;
                    did_emsg = FALSE;

                    syntax_attr = get_syntax_attr((colnr_T)v - 1,
# ifdef FEAT_SPELL
                                               has_spell ? &can_spell :
# endif
                                               NULL, FALSE);

                    if (did_emsg)
                    {
                        wp->w_buffer->b_syn_error = TRUE;
                        has_syntax = FALSE;
                    }
                    else
                        did_emsg = save_did_emsg;

                    /* Need to get the line again, a multi-line regexp may
                     * have made it invalid. */
                    line = ml_get_buf(wp->w_buffer, lnum, FALSE);
                    ptr = line + v;

                    if (!attr_pri)
                        char_attr = syntax_attr;
                    else
                        char_attr = hl_combine_attr(syntax_attr, char_attr);
                }
#endif

#ifdef FEAT_SPELL
                /* Check spelling (unless at the end of the line).
                 * Only do this when there is no syntax highlighting, the
                 * @Spell cluster is not used or the current syntax item
                 * contains the @Spell cluster. */
                if (has_spell && v >= word_end && v > cur_checked_col)
                {
                    spell_attr = 0;
# ifdef FEAT_SYN_HL
                    if (!attr_pri)
                        char_attr = syntax_attr;
# endif
                    if (c != 0 && (
# ifdef FEAT_SYN_HL
                                !has_syntax ||
# endif
                                can_spell))
                    {
                        char_u  *prev_ptr, *p;
                        int     len;
                        hlf_T   spell_hlf = HLF_COUNT;
# ifdef FEAT_MBYTE
                        if (has_mbyte)
                        {
                            prev_ptr = ptr - mb_l;
                            v -= mb_l - 1;
                        }
                        else
# endif
                            prev_ptr = ptr - 1;

                        /* Use nextline[] if possible, it has the start of the
                         * next line concatenated. */
                        if ((prev_ptr - line) - nextlinecol >= 0)
                            p = nextline + (prev_ptr - line) - nextlinecol;
                        else
                            p = prev_ptr;
                        cap_col -= (int)(prev_ptr - line);
                        len = spell_check(wp, p, &spell_hlf, &cap_col,
                                                                    nochange);
                        word_end = v + len;

                        /* In Insert mode only highlight a word that
                         * doesn't touch the cursor. */
                        if (spell_hlf != HLF_COUNT
                                && (State & INSERT) != 0
                                && wp->w_cursor.lnum == lnum
                                && wp->w_cursor.col >=
                                                    (colnr_T)(prev_ptr - line)
                                && wp->w_cursor.col < (colnr_T)word_end)
                        {
                            spell_hlf = HLF_COUNT;
                            spell_redraw_lnum = lnum;
                        }

                        if (spell_hlf == HLF_COUNT && p != prev_ptr
                                       && (p - nextline) + len > nextline_idx)
                        {
                            /* Remember that the good word continues at the
                             * start of the next line. */
                            checked_lnum = lnum + 1;
                            checked_col = (int)((p - nextline) + len - nextline_idx);
                        }

                        /* Turn index into actual attributes. */
                        if (spell_hlf != HLF_COUNT)
                            spell_attr = highlight_attr[spell_hlf];

                        if (cap_col > 0)
                        {
                            if (p != prev_ptr
                                   && (p - nextline) + cap_col >= nextline_idx)
                            {
                                /* Remember that the word in the next line
                                 * must start with a capital. */
                                capcol_lnum = lnum + 1;
                                cap_col = (int)((p - nextline) + cap_col
                                                               - nextline_idx);
                            }
                            else
                                /* Compute the actual column. */
                                cap_col += (int)(prev_ptr - line);
                        }
                    }
                }
                if (spell_attr != 0)
                {
                    if (!attr_pri)
                        char_attr = hl_combine_attr(char_attr, spell_attr);
                    else
                        char_attr = hl_combine_attr(spell_attr, char_attr);
                }
#endif
#ifdef FEAT_LINEBREAK
                /*
                 * Found last space before word: check for line break.
                 */
                if (wp->w_p_lbr && vim_isbreak(c) && !vim_isbreak(*ptr)
                                                             && !wp->w_p_list)
                {
                    n_extra = win_lbr_chartabsize(wp, ptr - (
# ifdef FEAT_MBYTE
                                has_mbyte ? mb_l :
# endif
                                1), (colnr_T)vcol, NULL) - 1;
                    c_extra = ' ';
                    if (vim_iswhite(c))
                        c = ' ';
                }
#endif

                if (trailcol != MAXCOL && ptr > line + trailcol && c == ' ')
                {
                    c = lcs_trail;
                    if (!attr_pri)
                    {
                        n_attr = 1;
                        extra_attr = hl_attr(HLF_8);
                        saved_attr2 = char_attr; /* save current attr */
                    }
#ifdef FEAT_MBYTE
                    mb_c = c;
                    if (enc_utf8 && (*mb_char2len)(c) > 1)
                    {
                        mb_utf8 = TRUE;
                        u8cc[0] = 0;
                        c = 0xc0;
                    }
                    else
                        mb_utf8 = FALSE;
#endif
                }
            }

            /*
             * Handling of non-printable characters.
             */
            if (!(chartab[c & 0xff] & CT_PRINT_CHAR))
            {
                /*
                 * when getting a character from the file, we may have to
                 * turn it into something else on the way to putting it
                 * into "ScreenLines".
                 */
                if (c == TAB && (!wp->w_p_list || lcs_tab1))
                {
                    /* tab amount depends on current column */
                    n_extra = (int)wp->w_buffer->b_p_ts
                                   - vcol % (int)wp->w_buffer->b_p_ts - 1;
#ifdef FEAT_MBYTE
                    mb_utf8 = FALSE;    /* don't draw as UTF-8 */
#endif
                    if (wp->w_p_list)
                    {
                        c = lcs_tab1;
                        c_extra = lcs_tab2;
                        n_attr = n_extra + 1;
                        extra_attr = hl_attr(HLF_8);
                        saved_attr2 = char_attr; /* save current attr */
#ifdef FEAT_MBYTE
                        mb_c = c;
                        if (enc_utf8 && (*mb_char2len)(c) > 1)
                        {
                            mb_utf8 = TRUE;
                            u8cc[0] = 0;
                            c = 0xc0;
                        }
#endif
                    }
                    else
                    {
                        c_extra = ' ';
                        c = ' ';
                    }
                }
                else if (c == NUL
                        && ((wp->w_p_list && lcs_eol > 0)
                            || ((fromcol >= 0 || fromcol_prev >= 0)
                                && tocol > vcol
#ifdef FEAT_VISUAL
                                && VIsual_mode != Ctrl_V
#endif
                                && (
# ifdef FEAT_RIGHTLEFT
                                    wp->w_p_rl ? (col >= 0) :
# endif
                                    (col < W_WIDTH(wp)))
                                && !(noinvcur
                                    && (colnr_T)vcol == wp->w_virtcol)))
                        && lcs_eol_one >= 0)
                {
                    /* Display a '$' after the line or highlight an extra
                     * character if the line break is included. */
#if defined(FEAT_DIFF) || defined(LINE_ATTR)
                    /* For a diff line the highlighting continues after the
                     * "$". */
                    if (
# ifdef FEAT_DIFF
                            diff_hlf == (hlf_T)0
#  ifdef LINE_ATTR
                            &&
#  endif
# endif
# ifdef LINE_ATTR
                            line_attr == 0
# endif
                       )
#endif
                    {
#ifdef FEAT_VIRTUALEDIT
                        /* In virtualedit, visual selections may extend
                         * beyond end of line. */
                        if (area_highlighting && virtual_active()
                                && tocol != MAXCOL && vcol < tocol)
                            n_extra = 0;
                        else
#endif
                        {
                            p_extra = at_end_str;
                            n_extra = 1;
                            c_extra = NUL;
                        }
                    }
                    if (wp->w_p_list)
                        c = lcs_eol;
                    else
                        c = ' ';
                    lcs_eol_one = -1;
                    --ptr;          /* put it back at the NUL */
                    if (!attr_pri)
                    {
                        extra_attr = hl_attr(HLF_AT);
                        n_attr = 1;
                    }
#ifdef FEAT_MBYTE
                    mb_c = c;
                    if (enc_utf8 && (*mb_char2len)(c) > 1)
                    {
                        mb_utf8 = TRUE;
                        u8cc[0] = 0;
                        c = 0xc0;
                    }
                    else
                        mb_utf8 = FALSE;        /* don't draw as UTF-8 */
#endif
                }
                else if (c != NUL)
                {
                    p_extra = transchar(c);
#ifdef FEAT_RIGHTLEFT
                    if ((dy_flags & DY_UHEX) && wp->w_p_rl)
                        rl_mirror(p_extra);     /* reverse "<12>" */
#endif
                    n_extra = byte2cells(c) - 1;
                    c_extra = NUL;
                    c = *p_extra++;
                    if (!attr_pri)
                    {
                        n_attr = n_extra + 1;
                        extra_attr = hl_attr(HLF_8);
                        saved_attr2 = char_attr; /* save current attr */
                    }
#ifdef FEAT_MBYTE
                    mb_utf8 = FALSE;    /* don't draw as UTF-8 */
#endif
                }
#ifdef FEAT_VIRTUALEDIT
                else if (VIsual_active
                         && (VIsual_mode == Ctrl_V
                             || VIsual_mode == 'v')
                         && virtual_active()
                         && tocol != MAXCOL
                         && vcol < tocol
                         && (
# ifdef FEAT_RIGHTLEFT
                            wp->w_p_rl ? (col >= 0) :
# endif
                            (col < W_WIDTH(wp))))
                {
                    c = ' ';
                    --ptr;          /* put it back at the NUL */
                }
#endif
#if defined(LINE_ATTR)
                else if ((
# ifdef FEAT_DIFF
                            diff_hlf != (hlf_T)0 ||
# endif
                            line_attr != 0
                        ) && (
# ifdef FEAT_RIGHTLEFT
                            wp->w_p_rl ? (col >= 0) :
# endif
                            (col < W_WIDTH(wp))))
                {
                    /* Highlight until the right side of the window */
                    c = ' ';
                    --ptr;          /* put it back at the NUL */

                    /* Remember we do the char for line highlighting. */
                    ++did_line_attr;

                    /* don't do search HL for the rest of the line */
                    if (line_attr != 0 && char_attr == search_attr && col > 0)
                        char_attr = line_attr;
# ifdef FEAT_DIFF
                    if (diff_hlf == HLF_TXD)
                    {
                        diff_hlf = HLF_CHD;
                        if (attr == 0 || char_attr != attr)
                            char_attr = hl_attr(diff_hlf);
                    }
# endif
                }
#endif
            }
        }

        /* Don't override visual selection highlighting. */
        if (n_attr > 0
                && draw_state == WL_LINE
                && !attr_pri)
            char_attr = extra_attr;

#if defined(FEAT_XIM) && defined(FEAT_GUI_GTK)
        /* XIM don't send preedit_start and preedit_end, but they send
         * preedit_changed and commit.  Thus Vim can't set "im_is_active", use
         * im_is_preediting() here. */
        if (xic != NULL
                && lnum == curwin->w_cursor.lnum
                && (State & INSERT)
                && !p_imdisable
                && im_is_preediting()
                && draw_state == WL_LINE)
        {
            colnr_T tcol;

            if (preedit_end_col == MAXCOL)
                getvcol(curwin, &(curwin->w_cursor), &tcol, NULL, NULL);
            else
                tcol = preedit_end_col;
            if ((long)preedit_start_col <= vcol && vcol < (long)tcol)
            {
                if (feedback_old_attr < 0)
                {
                    feedback_col = 0;
                    feedback_old_attr = char_attr;
                }
                char_attr = im_get_feedback_attr(feedback_col);
                if (char_attr < 0)
                    char_attr = feedback_old_attr;
                feedback_col++;
            }
            else if (feedback_old_attr >= 0)
            {
                char_attr = feedback_old_attr;
                feedback_old_attr = -1;
                feedback_col = 0;
            }
        }
#endif
        /*
         * Handle the case where we are in column 0 but not on the first
         * character of the line and the user wants us to show us a
         * special character (via 'listchars' option "precedes:<char>".
         */
        if (lcs_prec_todo != NUL
                && (wp->w_p_wrap ? wp->w_skipcol > 0 : wp->w_leftcol > 0)
#ifdef FEAT_DIFF
                && filler_todo <= 0
#endif
                && draw_state > WL_NR
                && c != NUL)
        {
            c = lcs_prec;
            lcs_prec_todo = NUL;
#ifdef FEAT_MBYTE
            mb_c = c;
            if (enc_utf8 && (*mb_char2len)(c) > 1)
            {
                mb_utf8 = TRUE;
                u8cc[0] = 0;
                c = 0xc0;
            }
            else
                mb_utf8 = FALSE;        /* don't draw as UTF-8 */
#endif
            if (!attr_pri)
            {
                saved_attr3 = char_attr; /* save current attr */
                char_attr = hl_attr(HLF_AT); /* later copied to char_attr */
                n_attr3 = 1;
            }
        }

        /*
         * At end of the text line or just after the last character.
         */
        if (c == NUL
#if defined(LINE_ATTR)
                || did_line_attr == 1
#endif
                )
        {
#ifdef FEAT_SEARCH_EXTRA
            long prevcol = (long)(ptr - line) - (c == NUL);

            /* we're not really at that column when skipping some text */
            if ((long)(wp->w_p_wrap ? wp->w_skipcol : wp->w_leftcol) > prevcol)
                ++prevcol;
#endif

            /* invert at least one char, used for Visual and empty line or
             * highlight match at end of line. If it's beyond the last
             * char on the screen, just overwrite that one (tricky!)  Not
             * needed when a '$' was displayed for 'list'. */
#ifdef FEAT_SEARCH_EXTRA
            prevcol_hl_flag = FALSE;
            if (prevcol == (long)search_hl.startcol)
                prevcol_hl_flag = TRUE;
            else
            {
                cur = wp->w_match_head;
                while (cur != NULL)
                {
                    if (prevcol == (long)cur->hl.startcol)
                    {
                        prevcol_hl_flag = TRUE;
                        break;
                    }
                    cur = cur->next;
                }
            }
#endif
            if (lcs_eol == lcs_eol_one
                    && ((area_attr != 0 && vcol == fromcol && c == NUL)
#ifdef FEAT_SEARCH_EXTRA
                        /* highlight 'hlsearch' match at end of line */
                        || (prevcol_hl_flag == TRUE
# if defined(LINE_ATTR)
                            && did_line_attr <= 1
# endif
                           )
#endif
                       ))
            {
                int n = 0;

#ifdef FEAT_RIGHTLEFT
                if (wp->w_p_rl)
                {
                    if (col < 0)
                        n = 1;
                }
                else
#endif
                {
                    if (col >= W_WIDTH(wp))
                        n = -1;
                }
                if (n != 0)
                {
                    /* At the window boundary, highlight the last character
                     * instead (better than nothing). */
                    off += n;
                    col += n;
                }
                else
                {
                    /* Add a blank character to highlight. */
                    ScreenLines[off] = ' ';
#ifdef FEAT_MBYTE
                    if (enc_utf8)
                        ScreenLinesUC[off] = 0;
#endif
                }
#ifdef FEAT_SEARCH_EXTRA
                if (area_attr == 0)
                {
                    /* Use attributes from match with highest priority among
                     * 'search_hl' and the match list. */
                    char_attr = search_hl.attr;
                    cur = wp->w_match_head;
                    shl_flag = FALSE;
                    while (cur != NULL || shl_flag == FALSE)
                    {
                        if (shl_flag == FALSE
                                && ((cur != NULL
                                        && cur->priority > SEARCH_HL_PRIORITY)
                                    || cur == NULL))
                        {
                            shl = &search_hl;
                            shl_flag = TRUE;
                        }
                        else
                            shl = &cur->hl;
                        if ((ptr - line) - 1 == (long)shl->startcol)
                            char_attr = shl->attr;
                        if (shl != &search_hl && cur != NULL)
                            cur = cur->next;
                    }
                }
#endif
                ScreenAttrs[off] = char_attr;
#ifdef FEAT_RIGHTLEFT
                if (wp->w_p_rl)
                {
                    --col;
                    --off;
                }
                else
#endif
                {
                    ++col;
                    ++off;
                }
                ++vcol;
#ifdef FEAT_SYN_HL
                eol_hl_off = 1;
#endif
            }
        }

        /*
         * At end of the text line.
         */
        if (c == NUL)
        {
#ifdef FEAT_SYN_HL
            if (eol_hl_off > 0 && vcol - eol_hl_off == (long)wp->w_virtcol)
            {
                /* highlight last char after line */
                --col;
                --off;
                --vcol;
            }

            /* Highlight 'cursorcolumn' past end of the line. */
            if (wp->w_p_wrap)
                v = wp->w_skipcol;
            else
                v = wp->w_leftcol;
            /* check if line ends before left margin */
            if (vcol < v + col - win_col_off(wp))

                vcol = v + col - win_col_off(wp);
            if (wp->w_p_cuc
                    && (int)wp->w_virtcol >= vcol - eol_hl_off
                    && (int)wp->w_virtcol < W_WIDTH(wp) * (row - startrow + 1)
                                                                           + v
                    && lnum != wp->w_cursor.lnum
# ifdef FEAT_RIGHTLEFT
                    && !wp->w_p_rl
# endif
                    )
            {
                while (col < W_WIDTH(wp))
                {
                    ScreenLines[off] = ' ';
#ifdef FEAT_MBYTE
                    if (enc_utf8)
                        ScreenLinesUC[off] = 0;
#endif
                    ++col;
                    if (vcol == (long)wp->w_virtcol)
                    {
                        ScreenAttrs[off] = hl_attr(HLF_CUC);
                        break;
                    }
                    ScreenAttrs[off++] = 0;
                    ++vcol;
                }
            }
#endif

            SCREEN_LINE(screen_row, W_WINCOL(wp), col, (int)W_WIDTH(wp),
                                                                  wp->w_p_rl);
            row++;

            /*
             * Update w_cline_height and w_cline_folded if the cursor line was
             * updated (saves a call to plines() later).
             */
            if (wp == curwin && lnum == curwin->w_cursor.lnum)
            {
                curwin->w_cline_row = startrow;
                curwin->w_cline_height = row - startrow;
#ifdef FEAT_FOLDING
                curwin->w_cline_folded = FALSE;
#endif
                curwin->w_valid |= (VALID_CHEIGHT|VALID_CROW);
            }

            break;
        }

        /* line continues beyond line end */
        if (lcs_ext
                && !wp->w_p_wrap
#ifdef FEAT_DIFF
                && filler_todo <= 0
#endif
                && (
#ifdef FEAT_RIGHTLEFT
                    wp->w_p_rl ? col == 0 :
#endif
                    col == W_WIDTH(wp) - 1)
                && (*ptr != NUL
                    || (wp->w_p_list && lcs_eol_one > 0)
                    || (n_extra && (c_extra != NUL || *p_extra != NUL))))
        {
            c = lcs_ext;
            char_attr = hl_attr(HLF_AT);
#ifdef FEAT_MBYTE
            mb_c = c;
            if (enc_utf8 && (*mb_char2len)(c) > 1)
            {
                mb_utf8 = TRUE;
                u8cc[0] = 0;
                c = 0xc0;
            }
            else
                mb_utf8 = FALSE;
#endif
        }

#ifdef FEAT_SYN_HL
        /* Highlight the cursor column if 'cursorcolumn' is set.  But don't
         * highlight the cursor position itself. */
        if (wp->w_p_cuc && vcol == (long)wp->w_virtcol
                && lnum != wp->w_cursor.lnum
                && draw_state == WL_LINE
                && !lnum_in_visual_area)
        {
            vcol_save_attr = char_attr;
            char_attr = hl_combine_attr(char_attr, hl_attr(HLF_CUC));
        }
        else
            vcol_save_attr = -1;
#endif

        /*
         * Store character to be displayed.
         * Skip characters that are left of the screen for 'nowrap'.
         */
        vcol_prev = vcol;
        if (draw_state < WL_LINE || n_skip <= 0)
        {
            /*
             * Store the character.
             */
#if defined(FEAT_RIGHTLEFT) && defined(FEAT_MBYTE)
            if (has_mbyte && wp->w_p_rl && (*mb_char2cells)(mb_c) > 1)
            {
                /* A double-wide character is: put first halve in left cell. */
                --off;
                --col;
            }
#endif
            ScreenLines[off] = c;
#ifdef FEAT_MBYTE
            if (enc_dbcs == DBCS_JPNU)
                ScreenLines2[off] = mb_c & 0xff;
            else if (enc_utf8)
            {
                if (mb_utf8)
                {
                    int i;

                    ScreenLinesUC[off] = mb_c;
                    if ((c & 0xff) == 0)
                        ScreenLines[off] = 0x80;   /* avoid storing zero */
                    for (i = 0; i < Screen_mco; ++i)
                    {
                        ScreenLinesC[i][off] = u8cc[i];
                        if (u8cc[i] == 0)
                            break;
                    }
                }
                else
                    ScreenLinesUC[off] = 0;
            }
            if (multi_attr)
            {
                ScreenAttrs[off] = multi_attr;
                multi_attr = 0;
            }
            else
#endif
                ScreenAttrs[off] = char_attr;

#ifdef FEAT_MBYTE
            if (has_mbyte && (*mb_char2cells)(mb_c) > 1)
            {
                /* Need to fill two screen columns. */
                ++off;
                ++col;
                if (enc_utf8)
                    /* UTF-8: Put a 0 in the second screen char. */
                    ScreenLines[off] = 0;
                else
                    /* DBCS: Put second byte in the second screen char. */
                    ScreenLines[off] = mb_c & 0xff;
                ++vcol;
                /* When "tocol" is halfway a character, set it to the end of
                 * the character, otherwise highlighting won't stop. */
                if (tocol == vcol)
                    ++tocol;
#ifdef FEAT_RIGHTLEFT
                if (wp->w_p_rl)
                {
                    /* now it's time to backup one cell */
                    --off;
                    --col;
                }
#endif
            }
#endif
#ifdef FEAT_RIGHTLEFT
            if (wp->w_p_rl)
            {
                --off;
                --col;
            }
            else
#endif
            {
                ++off;
                ++col;
            }
        }
        else
            --n_skip;

        /* Only advance the "vcol" when after the 'number' column. */
        if (draw_state > WL_NR
#ifdef FEAT_DIFF
                && filler_todo <= 0
#endif
                )
            ++vcol;

#ifdef FEAT_SYN_HL
        if (vcol_save_attr >= 0)
            char_attr = vcol_save_attr;
#endif

        /* restore attributes after "predeces" in 'listchars' */
        if (draw_state > WL_NR && n_attr3 > 0 && --n_attr3 == 0)
            char_attr = saved_attr3;

        /* restore attributes after last 'listchars' or 'number' char */
        if (n_attr > 0 && draw_state == WL_LINE && --n_attr == 0)
            char_attr = saved_attr2;

        /*
         * At end of screen line and there is more to come: Display the line
         * so far.  If there is no more to display it is caught above.
         */
        if ((
#ifdef FEAT_RIGHTLEFT
            wp->w_p_rl ? (col < 0) :
#endif
                                    (col >= W_WIDTH(wp)))
                && (*ptr != NUL
#ifdef FEAT_DIFF
                    || filler_todo > 0
#endif
                    || (wp->w_p_list && lcs_eol != NUL && p_extra != at_end_str)
                    || (n_extra != 0 && (c_extra != NUL || *p_extra != NUL)))
                )
        {
            SCREEN_LINE(screen_row, W_WINCOL(wp), col, (int)W_WIDTH(wp),
                                                                  wp->w_p_rl);
            ++row;
            ++screen_row;

            /* When not wrapping and finished diff lines, or when displayed
             * '$' and highlighting until last column, break here. */
            if ((!wp->w_p_wrap
#ifdef FEAT_DIFF
                    && filler_todo <= 0
#endif
                    ) || lcs_eol_one == -1)
                break;

            /* When the window is too narrow draw all "@" lines. */
            if (draw_state != WL_LINE
#ifdef FEAT_DIFF
                    && filler_todo <= 0
#endif
                    )
            {
                win_draw_end(wp, '@', ' ', row, wp->w_height, HLF_AT);
#ifdef FEAT_VERTSPLIT
                draw_vsep_win(wp, row);
#endif
                row = endrow;
            }

            /* When line got too long for screen break here. */
            if (row == endrow)
            {
                ++row;
                break;
            }

            if (screen_cur_row == screen_row - 1
#ifdef FEAT_DIFF
                     && filler_todo <= 0
#endif
                     && W_WIDTH(wp) == Columns)
            {
                /* Remember that the line wraps, used for modeless copy. */
                LineWraps[screen_row - 1] = TRUE;

                /*
                 * Special trick to make copy/paste of wrapped lines work with
                 * xterm/screen: write an extra character beyond the end of
                 * the line. This will work with all terminal types
                 * (regardless of the xn,am settings).
                 * Only do this on a fast tty.
                 * Only do this if the cursor is on the current line
                 * (something has been written in it).
                 * Don't do this for the GUI.
                 * Don't do this for double-width characters.
                 * Don't do this for a window not at the right screen border.
                 */
                if (p_tf
#ifdef FEAT_GUI
                         && !gui.in_use
#endif
#ifdef FEAT_MBYTE
                         && !(has_mbyte
                             && ((*mb_off2cells)(LineOffset[screen_row],
                                     LineOffset[screen_row] + screen_Columns)
                                                                          == 2
                                 || (*mb_off2cells)(LineOffset[screen_row - 1]
                                                        + (int)Columns - 2,
                                     LineOffset[screen_row] + screen_Columns)
                                                                        == 2))
#endif
                   )
                {
                    /* First make sure we are at the end of the screen line,
                     * then output the same character again to let the
                     * terminal know about the wrap.  If the terminal doesn't
                     * auto-wrap, we overwrite the character. */
                    if (screen_cur_col != W_WIDTH(wp))
                        screen_char(LineOffset[screen_row - 1]
                                                      + (unsigned)Columns - 1,
                                          screen_row - 1, (int)(Columns - 1));

#ifdef FEAT_MBYTE
                    /* When there is a multi-byte character, just output a
                     * space to keep it simple. */
                    if (has_mbyte && MB_BYTE2LEN(ScreenLines[LineOffset[
                                        screen_row - 1] + (Columns - 1)]) > 1)
                        out_char(' ');
                    else
#endif
                        out_char(ScreenLines[LineOffset[screen_row - 1]
                                                            + (Columns - 1)]);
                    /* force a redraw of the first char on the next line */
                    ScreenAttrs[LineOffset[screen_row]] = (sattr_T)-1;
                    screen_start();     /* don't know where cursor is now */
                }
            }

            col = 0;
            off = (unsigned)(current_ScreenLine - ScreenLines);
#ifdef FEAT_RIGHTLEFT
            if (wp->w_p_rl)
            {
                col = W_WIDTH(wp) - 1;  /* col is not used if breaking! */
                off += col;
            }
#endif

            /* reset the drawing state for the start of a wrapped line */
            draw_state = WL_START;
            saved_n_extra = n_extra;
            saved_p_extra = p_extra;
            saved_c_extra = c_extra;
            saved_char_attr = char_attr;
            n_extra = 0;
            lcs_prec_todo = lcs_prec;
#ifdef FEAT_LINEBREAK
# ifdef FEAT_DIFF
            if (filler_todo <= 0)
# endif
                need_showbreak = TRUE;
#endif
#ifdef FEAT_DIFF
            --filler_todo;
            /* When the filler lines are actually below the last line of the
             * file, don't draw the line itself, break here. */
            if (filler_todo == 0 && wp->w_botfill)
                break;
#endif
        }

    }   /* for every character in the line */

#ifdef FEAT_SPELL
    /* After an empty line check first word for capital. */
    if (*skipwhite(line) == NUL)
    {
        capcol_lnum = lnum + 1;
        cap_col = 0;
    }
#endif

    return row;
}

#ifdef FEAT_MBYTE
static int comp_char_differs __ARGS((int, int));

/*
 * Return if the composing characters at "off_from" and "off_to" differ.
 */
    static int
comp_char_differs(off_from, off_to)
    int     off_from;
    int     off_to;
{
    int     i;

    for (i = 0; i < Screen_mco; ++i)
    {
        if (ScreenLinesC[i][off_from] != ScreenLinesC[i][off_to])
            return TRUE;
        if (ScreenLinesC[i][off_from] == 0)
            break;
    }
    return FALSE;
}
#endif

/*
 * Check whether the given character needs redrawing:
 * - the (first byte of the) character is different
 * - the attributes are different
 * - the character is multi-byte and the next byte is different
 * - the character is two cells wide and the second cell differs.
 */
    static int
char_needs_redraw(off_from, off_to, cols)
    int         off_from;
    int         off_to;
    int         cols;
{
    if (cols > 0
            && ((ScreenLines[off_from] != ScreenLines[off_to]
                    || ScreenAttrs[off_from] != ScreenAttrs[off_to])

#ifdef FEAT_MBYTE
                || (enc_dbcs != 0
                    && MB_BYTE2LEN(ScreenLines[off_from]) > 1
                    && (enc_dbcs == DBCS_JPNU && ScreenLines[off_from] == 0x8e
                        ? ScreenLines2[off_from] != ScreenLines2[off_to]
                        : (cols > 1 && ScreenLines[off_from + 1]
                                                 != ScreenLines[off_to + 1])))
                || (enc_utf8
                    && (ScreenLinesUC[off_from] != ScreenLinesUC[off_to]
                        || (ScreenLinesUC[off_from] != 0
                            && comp_char_differs(off_from, off_to))
                        || (cols > 1 && ScreenLines[off_from + 1]
                                                 != ScreenLines[off_to + 1])))
#endif
               ))
        return TRUE;
    return FALSE;
}

/*
 * Move one "cooked" screen line to the screen, but only the characters that
 * have actually changed.  Handle insert/delete character.
 * "coloff" gives the first column on the screen for this line.
 * "endcol" gives the columns where valid characters are.
 * "clear_width" is the width of the window.  It's > 0 if the rest of the line
 * needs to be cleared, negative otherwise.
 * "rlflag" is TRUE in a rightleft window:
 *    When TRUE and "clear_width" > 0, clear columns 0 to "endcol"
 *    When FALSE and "clear_width" > 0, clear columns "endcol" to "clear_width"
 */
    static void
screen_line(row, coloff, endcol, clear_width
#ifdef FEAT_RIGHTLEFT
                                    , rlflag
#endif
                                                )
    int     row;
    int     coloff;
    int     endcol;
    int     clear_width;
#ifdef FEAT_RIGHTLEFT
    int     rlflag;
#endif
{
    unsigned        off_from;
    unsigned        off_to;
#ifdef FEAT_MBYTE
    unsigned        max_off_from;
    unsigned        max_off_to;
#endif
    int             col = 0;
#if defined(FEAT_GUI) || defined(UNIX) || defined(FEAT_VERTSPLIT)
    int             hl;
#endif
    int             force = FALSE;      /* force update rest of the line */
    int             redraw_this         /* bool: does character need redraw? */
#ifdef FEAT_GUI
                                = TRUE  /* For GUI when while-loop empty */
#endif
                                ;
    int             redraw_next;        /* redraw_this for next character */
#ifdef FEAT_MBYTE
    int             clear_next = FALSE;
    int             char_cells;         /* 1: normal char */
                                        /* 2: occupies two display cells */
# define CHAR_CELLS char_cells
#else
# define CHAR_CELLS 1
#endif

# ifdef FEAT_CLIPBOARD
    clip_may_clear_selection(row, row);
# endif

    off_from = (unsigned)(current_ScreenLine - ScreenLines);
    off_to = LineOffset[row] + coloff;
#ifdef FEAT_MBYTE
    max_off_from = off_from + screen_Columns;
    max_off_to = LineOffset[row] + screen_Columns;
#endif

#ifdef FEAT_RIGHTLEFT
    if (rlflag)
    {
        /* Clear rest first, because it's left of the text. */
        if (clear_width > 0)
        {
            while (col <= endcol && ScreenLines[off_to] == ' '
                    && ScreenAttrs[off_to] == 0
# ifdef FEAT_MBYTE
                                  && (!enc_utf8 || ScreenLinesUC[off_to] == 0)
# endif
                                                  )
            {
                ++off_to;
                ++col;
            }
            if (col <= endcol)
                screen_fill(row, row + 1, col + coloff,
                                            endcol + coloff + 1, ' ', ' ', 0);
        }
        col = endcol + 1;
        off_to = LineOffset[row] + col + coloff;
        off_from += col;
        endcol = (clear_width > 0 ? clear_width : -clear_width);
    }
#endif /* FEAT_RIGHTLEFT */

    redraw_next = char_needs_redraw(off_from, off_to, endcol - col);

    while (col < endcol)
    {
#ifdef FEAT_MBYTE
        if (has_mbyte && (col + 1 < endcol))
            char_cells = (*mb_off2cells)(off_from, max_off_from);
        else
            char_cells = 1;
#endif

        redraw_this = redraw_next;
        redraw_next = force || char_needs_redraw(off_from + CHAR_CELLS,
                              off_to + CHAR_CELLS, endcol - col - CHAR_CELLS);

#ifdef FEAT_GUI
        /* If the next character was bold, then redraw the current character to
         * remove any pixels that might have spilt over into us.  This only
         * happens in the GUI.
         */
        if (redraw_next && gui.in_use)
        {
            hl = ScreenAttrs[off_to + CHAR_CELLS];
            if (hl > HL_ALL)
                hl = syn_attr2attr(hl);
            if (hl & HL_BOLD)
                redraw_this = TRUE;
        }
#endif

        if (redraw_this)
        {
            /*
             * Special handling when 'xs' termcap flag set (hpterm):
             * Attributes for characters are stored at the position where the
             * cursor is when writing the highlighting code.  The
             * start-highlighting code must be written with the cursor on the
             * first highlighted character.  The stop-highlighting code must
             * be written with the cursor just after the last highlighted
             * character.
             * Overwriting a character doesn't remove it's highlighting.  Need
             * to clear the rest of the line, and force redrawing it
             * completely.
             */
            if (       p_wiv
                    && !force
#ifdef FEAT_GUI
                    && !gui.in_use
#endif
                    && ScreenAttrs[off_to] != 0
                    && ScreenAttrs[off_from] != ScreenAttrs[off_to])
            {
                /*
                 * Need to remove highlighting attributes here.
                 */
                windgoto(row, col + coloff);
                out_str(T_CE);          /* clear rest of this screen line */
                screen_start();         /* don't know where cursor is now */
                force = TRUE;           /* force redraw of rest of the line */
                redraw_next = TRUE;     /* or else next char would miss out */

                /*
                 * If the previous character was highlighted, need to stop
                 * highlighting at this character.
                 */
                if (col + coloff > 0 && ScreenAttrs[off_to - 1] != 0)
                {
                    screen_attr = ScreenAttrs[off_to - 1];
                    term_windgoto(row, col + coloff);
                    screen_stop_highlight();
                }
                else
                    screen_attr = 0;        /* highlighting has stopped */
            }
#ifdef FEAT_MBYTE
            if (enc_dbcs != 0)
            {
                /* Check if overwriting a double-byte with a single-byte or
                 * the other way around requires another character to be
                 * redrawn.  For UTF-8 this isn't needed, because comparing
                 * ScreenLinesUC[] is sufficient. */
                if (char_cells == 1
                        && col + 1 < endcol
                        && (*mb_off2cells)(off_to, max_off_to) > 1)
                {
                    /* Writing a single-cell character over a double-cell
                     * character: need to redraw the next cell. */
                    ScreenLines[off_to + 1] = 0;
                    redraw_next = TRUE;
                }
                else if (char_cells == 2
                        && col + 2 < endcol
                        && (*mb_off2cells)(off_to, max_off_to) == 1
                        && (*mb_off2cells)(off_to + 1, max_off_to) > 1)
                {
                    /* Writing the second half of a double-cell character over
                     * a double-cell character: need to redraw the second
                     * cell. */
                    ScreenLines[off_to + 2] = 0;
                    redraw_next = TRUE;
                }

                if (enc_dbcs == DBCS_JPNU)
                    ScreenLines2[off_to] = ScreenLines2[off_from];
            }
            /* When writing a single-width character over a double-width
             * character and at the end of the redrawn text, need to clear out
             * the right halve of the old character.
             * Also required when writing the right halve of a double-width
             * char over the left halve of an existing one. */
            if (has_mbyte && col + char_cells == endcol
                    && ((char_cells == 1
                            && (*mb_off2cells)(off_to, max_off_to) > 1)
                        || (char_cells == 2
                            && (*mb_off2cells)(off_to, max_off_to) == 1
                            && (*mb_off2cells)(off_to + 1, max_off_to) > 1)))
                clear_next = TRUE;
#endif

            ScreenLines[off_to] = ScreenLines[off_from];
#ifdef FEAT_MBYTE
            if (enc_utf8)
            {
                ScreenLinesUC[off_to] = ScreenLinesUC[off_from];
                if (ScreenLinesUC[off_from] != 0)
                {
                    int     i;

                    for (i = 0; i < Screen_mco; ++i)
                        ScreenLinesC[i][off_to] = ScreenLinesC[i][off_from];
                }
            }
            if (char_cells == 2)
                ScreenLines[off_to + 1] = ScreenLines[off_from + 1];
#endif

#if defined(FEAT_GUI) || defined(UNIX)
            /* The bold trick makes a single column of pixels appear in the
             * next character.  When a bold character is removed, the next
             * character should be redrawn too.  This happens for our own GUI
             * and for some xterms. */
            if (
# ifdef FEAT_GUI
                    gui.in_use
# endif
# if defined(FEAT_GUI) && defined(UNIX)
                    ||
# endif
# ifdef UNIX
                    term_is_xterm
# endif
                    )
            {
                hl = ScreenAttrs[off_to];
                if (hl > HL_ALL)
                    hl = syn_attr2attr(hl);
                if (hl & HL_BOLD)
                    redraw_next = TRUE;
            }
#endif
            ScreenAttrs[off_to] = ScreenAttrs[off_from];
#ifdef FEAT_MBYTE
            /* For simplicity set the attributes of second half of a
             * double-wide character equal to the first half. */
            if (char_cells == 2)
                ScreenAttrs[off_to + 1] = ScreenAttrs[off_from];

            if (enc_dbcs != 0 && char_cells == 2)
                screen_char_2(off_to, row, col + coloff);
            else
#endif
                screen_char(off_to, row, col + coloff);
        }
        else if (  p_wiv
#ifdef FEAT_GUI
                && !gui.in_use
#endif
                && col + coloff > 0)
        {
            if (ScreenAttrs[off_to] == ScreenAttrs[off_to - 1])
            {
                /*
                 * Don't output stop-highlight when moving the cursor, it will
                 * stop the highlighting when it should continue.
                 */
                screen_attr = 0;
            }
            else if (screen_attr != 0)
                screen_stop_highlight();
        }

        off_to += CHAR_CELLS;
        off_from += CHAR_CELLS;
        col += CHAR_CELLS;
    }

#ifdef FEAT_MBYTE
    if (clear_next)
    {
        /* Clear the second half of a double-wide character of which the left
         * half was overwritten with a single-wide character. */
        ScreenLines[off_to] = ' ';
        if (enc_utf8)
            ScreenLinesUC[off_to] = 0;
        screen_char(off_to, row, col + coloff);
    }
#endif

    if (clear_width > 0
#ifdef FEAT_RIGHTLEFT
                    && !rlflag
#endif
                                   )
    {
#ifdef FEAT_GUI
        int startCol = col;
#endif

        /* blank out the rest of the line */
        while (col < clear_width && ScreenLines[off_to] == ' '
                                                  && ScreenAttrs[off_to] == 0
#ifdef FEAT_MBYTE
                                  && (!enc_utf8 || ScreenLinesUC[off_to] == 0)
#endif
                                                  )
        {
            ++off_to;
            ++col;
        }
        if (col < clear_width)
        {
#ifdef FEAT_GUI
            /*
             * In the GUI, clearing the rest of the line may leave pixels
             * behind if the first character cleared was bold.  Some bold
             * fonts spill over the left.  In this case we redraw the previous
             * character too.  If we didn't skip any blanks above, then we
             * only redraw if the character wasn't already redrawn anyway.
             */
            if (gui.in_use && (col > startCol || !redraw_this))
            {
                hl = ScreenAttrs[off_to];
                if (hl > HL_ALL || (hl & HL_BOLD))
                {
                    int prev_cells = 1;
# ifdef FEAT_MBYTE
                    if (enc_utf8)
                        /* for utf-8, ScreenLines[char_offset + 1] == 0 means
                         * that its width is 2. */
                        prev_cells = ScreenLines[off_to - 1] == 0 ? 2 : 1;
                    else if (enc_dbcs != 0)
                    {
                        /* find previous character by counting from first
                         * column and get its width. */
                        unsigned off = LineOffset[row];
                        unsigned max_off = LineOffset[row] + screen_Columns;

                        while (off < off_to)
                        {
                            prev_cells = (*mb_off2cells)(off, max_off);
                            off += prev_cells;
                        }
                    }

                    if (enc_dbcs != 0 && prev_cells > 1)
                        screen_char_2(off_to - prev_cells, row,
                                                   col + coloff - prev_cells);
                    else
# endif
                        screen_char(off_to - prev_cells, row,
                                                   col + coloff - prev_cells);
                }
            }
#endif
            screen_fill(row, row + 1, col + coloff, clear_width + coloff,
                                                                 ' ', ' ', 0);
#ifdef FEAT_VERTSPLIT
            off_to += clear_width - col;
            col = clear_width;
#endif
        }
    }

    if (clear_width > 0)
    {
#ifdef FEAT_VERTSPLIT
        /* For a window that's left of another, draw the separator char. */
        if (col + coloff < Columns)
        {
            int c;

            c = fillchar_vsep(&hl);
            if (ScreenLines[off_to] != c
# ifdef FEAT_MBYTE
                    || (enc_utf8 && (int)ScreenLinesUC[off_to]
                                                       != (c >= 0x80 ? c : 0))
# endif
                    || ScreenAttrs[off_to] != hl)
            {
                ScreenLines[off_to] = c;
                ScreenAttrs[off_to] = hl;
# ifdef FEAT_MBYTE
                if (enc_utf8)
                {
                    if (c >= 0x80)
                    {
                        ScreenLinesUC[off_to] = c;
                        ScreenLinesC[0][off_to] = 0;
                    }
                    else
                        ScreenLinesUC[off_to] = 0;
                }
# endif
                screen_char(off_to, row, col + coloff);
            }
        }
        else
#endif
            LineWraps[row] = FALSE;
    }
}

#if defined(FEAT_RIGHTLEFT) || defined(PROTO)
/*
 * Mirror text "str" for right-left displaying.
 * Only works for single-byte characters (e.g., numbers).
 */
    void
rl_mirror(str)
    char_u      *str;
{
    char_u      *p1, *p2;
    int         t;

    for (p1 = str, p2 = str + STRLEN(str) - 1; p1 < p2; ++p1, --p2)
    {
        t = *p1;
        *p1 = *p2;
        *p2 = t;
    }
}
#endif

#if defined(FEAT_WINDOWS) || defined(PROTO)
/*
 * mark all status lines for redraw; used after first :cd
 */
    void
status_redraw_all()
{
    win_T       *wp;

    for (wp = firstwin; wp; wp = wp->w_next)
        if (wp->w_status_height)
        {
            wp->w_redr_status = TRUE;
            redraw_later(VALID);
        }
}

/*
 * mark all status lines of the current buffer for redraw
 */
    void
status_redraw_curbuf()
{
    win_T       *wp;

    for (wp = firstwin; wp; wp = wp->w_next)
        if (wp->w_status_height != 0 && wp->w_buffer == curbuf)
        {
            wp->w_redr_status = TRUE;
            redraw_later(VALID);
        }
}

/*
 * Redraw all status lines that need to be redrawn.
 */
    void
redraw_statuslines()
{
    win_T       *wp;

    for (wp = firstwin; wp; wp = wp->w_next)
        if (wp->w_redr_status)
            win_redr_status(wp);
    if (redraw_tabline)
        draw_tabline();
}
#endif

#if (defined(FEAT_WILDMENU) && defined(FEAT_VERTSPLIT)) || defined(PROTO)
/*
 * Redraw all status lines at the bottom of frame "frp".
 */
    void
win_redraw_last_status(frp)
    frame_T     *frp;
{
    if (frp->fr_layout == FR_LEAF)
        frp->fr_win->w_redr_status = TRUE;
    else if (frp->fr_layout == FR_ROW)
    {
        for (frp = frp->fr_child; frp != NULL; frp = frp->fr_next)
            win_redraw_last_status(frp);
    }
    else /* frp->fr_layout == FR_COL */
    {
        frp = frp->fr_child;
        while (frp->fr_next != NULL)
            frp = frp->fr_next;
        win_redraw_last_status(frp);
    }
}
#endif

#ifdef FEAT_VERTSPLIT
/*
 * Draw the verticap separator right of window "wp" starting with line "row".
 */
    static void
draw_vsep_win(wp, row)
    win_T       *wp;
    int         row;
{
    int         hl;
    int         c;

    if (wp->w_vsep_width)
    {
        /* draw the vertical separator right of this window */
        c = fillchar_vsep(&hl);
        screen_fill(W_WINROW(wp) + row, W_WINROW(wp) + wp->w_height,
                W_ENDCOL(wp), W_ENDCOL(wp) + 1,
                c, ' ', hl);
    }
}
#endif

#ifdef FEAT_WILDMENU
static int status_match_len __ARGS((expand_T *xp, char_u *s));
static int skip_status_match_char __ARGS((expand_T *xp, char_u *s));

/*
 * Get the length of an item as it will be shown in the status line.
 */
    static int
status_match_len(xp, s)
    expand_T    *xp;
    char_u      *s;
{
    int len = 0;

#ifdef FEAT_MENU
    int emenu = (xp->xp_context == EXPAND_MENUS
            || xp->xp_context == EXPAND_MENUNAMES);

    /* Check for menu separators - replace with '|'. */
    if (emenu && menu_is_separator(s))
        return 1;
#endif

    while (*s != NUL)
    {
        s += skip_status_match_char(xp, s);
        len += ptr2cells(s);
        mb_ptr_adv(s);
    }

    return len;
}

/*
 * Return the number of characters that should be skipped in a status match.
 * These are backslashes used for escaping.  Do show backslashes in help tags.
 */
    static int
skip_status_match_char(xp, s)
    expand_T    *xp;
    char_u      *s;
{
    if ((rem_backslash(s) && xp->xp_context != EXPAND_HELP)
#ifdef FEAT_MENU
            || ((xp->xp_context == EXPAND_MENUS
                    || xp->xp_context == EXPAND_MENUNAMES)
                          && (s[0] == '\t' || (s[0] == '\\' && s[1] != NUL)))
#endif
           )
    {
#ifndef BACKSLASH_IN_FILENAME
        if (xp->xp_shell && csh_like_shell() && s[1] == '\\' && s[2] == '!')
            return 2;
#endif
        return 1;
    }
    return 0;
}

/*
 * Show wildchar matches in the status line.
 * Show at least the "match" item.
 * We start at item 'first_match' in the list and show all matches that fit.
 *
 * If inversion is possible we use it. Else '=' characters are used.
 */
    void
win_redr_status_matches(xp, num_matches, matches, match, showtail)
    expand_T    *xp;
    int         num_matches;
    char_u      **matches;      /* list of matches */
    int         match;
    int         showtail;
{
#define L_MATCH(m) (showtail ? sm_gettail(matches[m]) : matches[m])
    int         row;
    char_u      *buf;
    int         len;
    int         clen;           /* length in screen cells */
    int         fillchar;
    int         attr;
    int         i;
    int         highlight = TRUE;
    char_u      *selstart = NULL;
    int         selstart_col = 0;
    char_u      *selend = NULL;
    static int  first_match = 0;
    int         add_left = FALSE;
    char_u      *s;
#ifdef FEAT_MENU
    int         emenu;
#endif
#if defined(FEAT_MBYTE) || defined(FEAT_MENU)
    int         l;
#endif

    if (matches == NULL)        /* interrupted completion? */
        return;

#ifdef FEAT_MBYTE
    if (has_mbyte)
        buf = alloc((unsigned)Columns * MB_MAXBYTES + 1);
    else
#endif
        buf = alloc((unsigned)Columns + 1);
    if (buf == NULL)
        return;

    if (match == -1)    /* don't show match but original text */
    {
        match = 0;
        highlight = FALSE;
    }
    /* count 1 for the ending ">" */
    clen = status_match_len(xp, L_MATCH(match)) + 3;
    if (match == 0)
        first_match = 0;
    else if (match < first_match)
    {
        /* jumping left, as far as we can go */
        first_match = match;
        add_left = TRUE;
    }
    else
    {
        /* check if match fits on the screen */
        for (i = first_match; i < match; ++i)
            clen += status_match_len(xp, L_MATCH(i)) + 2;
        if (first_match > 0)
            clen += 2;
        /* jumping right, put match at the left */
        if ((long)clen > Columns)
        {
            first_match = match;
            /* if showing the last match, we can add some on the left */
            clen = 2;
            for (i = match; i < num_matches; ++i)
            {
                clen += status_match_len(xp, L_MATCH(i)) + 2;
                if ((long)clen >= Columns)
                    break;
            }
            if (i == num_matches)
                add_left = TRUE;
        }
    }
    if (add_left)
        while (first_match > 0)
        {
            clen += status_match_len(xp, L_MATCH(first_match - 1)) + 2;
            if ((long)clen >= Columns)
                break;
            --first_match;
        }

    fillchar = fillchar_status(&attr, TRUE);

    if (first_match == 0)
    {
        *buf = NUL;
        len = 0;
    }
    else
    {
        STRCPY(buf, "< ");
        len = 2;
    }
    clen = len;

    i = first_match;
    while ((long)(clen + status_match_len(xp, L_MATCH(i)) + 2) < Columns)
    {
        if (i == match)
        {
            selstart = buf + len;
            selstart_col = clen;
        }

        s = L_MATCH(i);
        /* Check for menu separators - replace with '|' */
#ifdef FEAT_MENU
        emenu = (xp->xp_context == EXPAND_MENUS
                || xp->xp_context == EXPAND_MENUNAMES);
        if (emenu && menu_is_separator(s))
        {
            STRCPY(buf + len, transchar('|'));
            l = (int)STRLEN(buf + len);
            len += l;
            clen += l;
        }
        else
#endif
            for ( ; *s != NUL; ++s)
        {
            s += skip_status_match_char(xp, s);
            clen += ptr2cells(s);
#ifdef FEAT_MBYTE
            if (has_mbyte && (l = (*mb_ptr2len)(s)) > 1)
            {
                STRNCPY(buf + len, s, l);
                s += l - 1;
                len += l;
            }
            else
#endif
            {
                STRCPY(buf + len, transchar_byte(*s));
                len += (int)STRLEN(buf + len);
            }
        }
        if (i == match)
            selend = buf + len;

        *(buf + len++) = ' ';
        *(buf + len++) = ' ';
        clen += 2;
        if (++i == num_matches)
                break;
    }

    if (i != num_matches)
    {
        *(buf + len++) = '>';
        ++clen;
    }

    buf[len] = NUL;

    row = cmdline_row - 1;
    if (row >= 0)
    {
        if (wild_menu_showing == 0)
        {
            if (msg_scrolled > 0)
            {
                /* Put the wildmenu just above the command line.  If there is
                 * no room, scroll the screen one line up. */
                if (cmdline_row == Rows - 1)
                {
                    screen_del_lines(0, 0, 1, (int)Rows, TRUE, NULL);
                    ++msg_scrolled;
                }
                else
                {
                    ++cmdline_row;
                    ++row;
                }
                wild_menu_showing = WM_SCROLLED;
            }
            else
            {
                /* Create status line if needed by setting 'laststatus' to 2.
                 * Set 'winminheight' to zero to avoid that the window is
                 * resized. */
                if (lastwin->w_status_height == 0)
                {
                    save_p_ls = p_ls;
                    save_p_wmh = p_wmh;
                    p_ls = 2;
                    p_wmh = 0;
                    last_status(FALSE);
                }
                wild_menu_showing = WM_SHOWN;
            }
        }

        screen_puts(buf, row, 0, attr);
        if (selstart != NULL && highlight)
        {
            *selend = NUL;
            screen_puts(selstart, row, selstart_col, hl_attr(HLF_WM));
        }

        screen_fill(row, row + 1, clen, (int)Columns, fillchar, fillchar, attr);
    }

#ifdef FEAT_VERTSPLIT
    win_redraw_last_status(topframe);
#else
    lastwin->w_redr_status = TRUE;
#endif
    vim_free(buf);
}
#endif

#if defined(FEAT_WINDOWS) || defined(PROTO)
/*
 * Redraw the status line of window wp.
 *
 * If inversion is possible we use it. Else '=' characters are used.
 */
    void
win_redr_status(wp)
    win_T       *wp;
{
    int         row;
    char_u      *p;
    int         len;
    int         fillchar;
    int         attr;
    int         this_ru_col;

    wp->w_redr_status = FALSE;
    if (wp->w_status_height == 0)
    {
        /* no status line, can only be last window */
        redraw_cmdline = TRUE;
    }
    else if (!redrawing()
#ifdef FEAT_INS_EXPAND
            /* don't update status line when popup menu is visible and may be
             * drawn over it */
            || pum_visible()
#endif
            )
    {
        /* Don't redraw right now, do it later. */
        wp->w_redr_status = TRUE;
    }
#ifdef FEAT_STL_OPT
    else if (*p_stl != NUL || *wp->w_p_stl != NUL)
    {
        /* redraw custom status line */
        redraw_custum_statusline(wp);
    }
#endif
    else
    {
        fillchar = fillchar_status(&attr, wp == curwin);

        get_trans_bufname(wp->w_buffer);
        p = NameBuff;
        len = (int)STRLEN(p);

        if (wp->w_buffer->b_help
#ifdef FEAT_QUICKFIX
                || wp->w_p_pvw
#endif
                || bufIsChanged(wp->w_buffer)
                || wp->w_buffer->b_p_ro)
            *(p + len++) = ' ';
        if (wp->w_buffer->b_help)
        {
            STRCPY(p + len, _("[Help]"));
            len += (int)STRLEN(p + len);
        }
#ifdef FEAT_QUICKFIX
        if (wp->w_p_pvw)
        {
            STRCPY(p + len, _("[Preview]"));
            len += (int)STRLEN(p + len);
        }
#endif
        if (bufIsChanged(wp->w_buffer))
        {
            STRCPY(p + len, "[+]");
            len += 3;
        }
        if (wp->w_buffer->b_p_ro)
        {
            STRCPY(p + len, "[RO]");
            len += 4;
        }

#ifndef FEAT_VERTSPLIT
        this_ru_col = ru_col;
        if (this_ru_col < (Columns + 1) / 2)
            this_ru_col = (Columns + 1) / 2;
#else
        this_ru_col = ru_col - (Columns - W_WIDTH(wp));
        if (this_ru_col < (W_WIDTH(wp) + 1) / 2)
            this_ru_col = (W_WIDTH(wp) + 1) / 2;
        if (this_ru_col <= 1)
        {
            p = (char_u *)"<";          /* No room for file name! */
            len = 1;
        }
        else
#endif
#ifdef FEAT_MBYTE
            if (has_mbyte)
            {
                int     clen = 0, i;

                /* Count total number of display cells. */
                for (i = 0; p[i] != NUL; i += (*mb_ptr2len)(p + i))
                    clen += (*mb_ptr2cells)(p + i);
                /* Find first character that will fit.
                 * Going from start to end is much faster for DBCS. */
                for (i = 0; p[i] != NUL && clen >= this_ru_col - 1;
                                              i += (*mb_ptr2len)(p + i))
                    clen -= (*mb_ptr2cells)(p + i);
                len = clen;
                if (i > 0)
                {
                    p = p + i - 1;
                    *p = '<';
                    ++len;
                }

            }
            else
#endif
            if (len > this_ru_col - 1)
            {
                p += len - (this_ru_col - 1);
                *p = '<';
                len = this_ru_col - 1;
            }

        row = W_WINROW(wp) + wp->w_height;
        screen_puts(p, row, W_WINCOL(wp), attr);
        screen_fill(row, row + 1, len + W_WINCOL(wp),
                        this_ru_col + W_WINCOL(wp), fillchar, fillchar, attr);

        if (get_keymap_str(wp, NameBuff, MAXPATHL)
                && (int)(this_ru_col - len) > (int)(STRLEN(NameBuff) + 1))
            screen_puts(NameBuff, row, (int)(this_ru_col - STRLEN(NameBuff)
                                                   - 1 + W_WINCOL(wp)), attr);

#ifdef FEAT_CMDL_INFO
        win_redr_ruler(wp, TRUE);
#endif
    }

#ifdef FEAT_VERTSPLIT
    /*
     * May need to draw the character below the vertical separator.
     */
    if (wp->w_vsep_width != 0 && wp->w_status_height != 0 && redrawing())
    {
        if (stl_connected(wp))
            fillchar = fillchar_status(&attr, wp == curwin);
        else
            fillchar = fillchar_vsep(&attr);
        screen_putchar(fillchar, W_WINROW(wp) + wp->w_height, W_ENDCOL(wp),
                                                                        attr);
    }
#endif
}

#ifdef FEAT_STL_OPT
/*
 * Redraw the status line according to 'statusline' and take care of any
 * errors encountered.
 */
    static void
redraw_custum_statusline(wp)
    win_T           *wp;
{
    int save_called_emsg = called_emsg;

    called_emsg = FALSE;
    win_redr_custom(wp, FALSE);
    if (called_emsg)
        set_string_option_direct((char_u *)"statusline", -1,
                (char_u *)"", OPT_FREE | (*wp->w_p_stl != NUL
                                        ? OPT_LOCAL : OPT_GLOBAL), SID_ERROR);
    called_emsg |= save_called_emsg;
}
#endif

# ifdef FEAT_VERTSPLIT
/*
 * Return TRUE if the status line of window "wp" is connected to the status
 * line of the window right of it.  If not, then it's a vertical separator.
 * Only call if (wp->w_vsep_width != 0).
 */
    int
stl_connected(wp)
    win_T       *wp;
{
    frame_T     *fr;

    fr = wp->w_frame;
    while (fr->fr_parent != NULL)
    {
        if (fr->fr_parent->fr_layout == FR_COL)
        {
            if (fr->fr_next != NULL)
                break;
        }
        else
        {
            if (fr->fr_next != NULL)
                return TRUE;
        }
        fr = fr->fr_parent;
    }
    return FALSE;
}
# endif

#endif /* FEAT_WINDOWS */

#if defined(FEAT_WINDOWS) || defined(FEAT_STL_OPT) || defined(PROTO)
/*
 * Get the value to show for the language mappings, active 'keymap'.
 */
    int
get_keymap_str(wp, buf, len)
    win_T       *wp;
    char_u      *buf;       /* buffer for the result */
    int         len;        /* length of buffer */
{
    char_u      *p;

    if (wp->w_buffer->b_p_iminsert != B_IMODE_LMAP)
        return FALSE;

    {
#ifdef FEAT_EVAL
        buf_T   *old_curbuf = curbuf;
        win_T   *old_curwin = curwin;
        char_u  *s;

        curbuf = wp->w_buffer;
        curwin = wp;
        STRCPY(buf, "b:keymap_name");   /* must be writable */
        ++emsg_skip;
        s = p = eval_to_string(buf, NULL, FALSE);
        --emsg_skip;
        curbuf = old_curbuf;
        curwin = old_curwin;
        if (p == NULL || *p == NUL)
#endif
        {
#ifdef FEAT_KEYMAP
            if (wp->w_buffer->b_kmap_state & KEYMAP_LOADED)
                p = wp->w_buffer->b_p_keymap;
            else
#endif
                p = (char_u *)"lang";
        }
        if ((int)(STRLEN(p) + 3) < len)
            sprintf((char *)buf, "<%s>", p);
        else
            buf[0] = NUL;
#ifdef FEAT_EVAL
        vim_free(s);
#endif
    }
    return buf[0] != NUL;
}
#endif

#if defined(FEAT_STL_OPT) || defined(PROTO)
/*
 * Redraw the status line or ruler of window "wp".
 * When "wp" is NULL redraw the tab pages line from 'tabline'.
 */
    static void
win_redr_custom(wp, draw_ruler)
    win_T       *wp;
    int         draw_ruler;     /* TRUE or FALSE */
{
    int         attr;
    int         curattr;
    int         row;
    int         col = 0;
    int         maxwidth;
    int         width;
    int         n;
    int         len;
    int         fillchar;
    char_u      buf[MAXPATHL];
    char_u      *p;
    struct      stl_hlrec hltab[STL_MAX_ITEM];
    struct      stl_hlrec tabtab[STL_MAX_ITEM];
    int         use_sandbox = FALSE;

    /* setup environment for the task at hand */
    if (wp == NULL)
    {
        /* Use 'tabline'.  Always at the first line of the screen. */
        p = p_tal;
        row = 0;
        fillchar = ' ';
        attr = hl_attr(HLF_TPF);
        maxwidth = Columns;
# ifdef FEAT_EVAL
        use_sandbox = was_set_insecurely((char_u *)"tabline", 0);
# endif
    }
    else
    {
        row = W_WINROW(wp) + wp->w_height;
        fillchar = fillchar_status(&attr, wp == curwin);
        maxwidth = W_WIDTH(wp);

        if (draw_ruler)
        {
            p = p_ruf;
            /* advance past any leading group spec - implicit in ru_col */
            if (*p == '%')
            {
                if (*++p == '-')
                    p++;
                if (atoi((char *) p))
                    while (VIM_ISDIGIT(*p))
                        p++;
                if (*p++ != '(')
                    p = p_ruf;
            }
#ifdef FEAT_VERTSPLIT
            col = ru_col - (Columns - W_WIDTH(wp));
            if (col < (W_WIDTH(wp) + 1) / 2)
                col = (W_WIDTH(wp) + 1) / 2;
#else
            col = ru_col;
            if (col > (Columns + 1) / 2)
                col = (Columns + 1) / 2;
#endif
            maxwidth = W_WIDTH(wp) - col;
#ifdef FEAT_WINDOWS
            if (!wp->w_status_height)
#endif
            {
                row = Rows - 1;
                --maxwidth;     /* writing in last column may cause scrolling */
                fillchar = ' ';
                attr = 0;
            }

# ifdef FEAT_EVAL
            use_sandbox = was_set_insecurely((char_u *)"rulerformat", 0);
# endif
        }
        else
        {
            if (*wp->w_p_stl != NUL)
                p = wp->w_p_stl;
            else
                p = p_stl;
# ifdef FEAT_EVAL
            use_sandbox = was_set_insecurely((char_u *)"statusline",
                                         *wp->w_p_stl == NUL ? 0 : OPT_LOCAL);
# endif
        }

#ifdef FEAT_VERTSPLIT
        col += W_WINCOL(wp);
#endif
    }

    if (maxwidth <= 0)
        return;

    width = build_stl_str_hl(wp == NULL ? curwin : wp,
                                buf, sizeof(buf),
                                p, use_sandbox,
                                fillchar, maxwidth, hltab, tabtab);
    len = (int)STRLEN(buf);

    while (width < maxwidth && len < sizeof(buf) - 1)
    {
#ifdef FEAT_MBYTE
        len += (*mb_char2bytes)(fillchar, buf + len);
#else
        buf[len++] = fillchar;
#endif
        ++width;
    }
    buf[len] = NUL;

    /*
     * Draw each snippet with the specified highlighting.
     */
    curattr = attr;
    p = buf;
    for (n = 0; hltab[n].start != NULL; n++)
    {
        len = (int)(hltab[n].start - p);
        screen_puts_len(p, len, row, col, curattr);
        col += vim_strnsize(p, len);
        p = hltab[n].start;

        if (hltab[n].userhl == 0)
            curattr = attr;
        else if (hltab[n].userhl < 0)
            curattr = syn_id2attr(-hltab[n].userhl);
#ifdef FEAT_WINDOWS
        else if (wp != NULL && wp != curwin && wp->w_status_height != 0)
            curattr = highlight_stlnc[hltab[n].userhl - 1];
#endif
        else
            curattr = highlight_user[hltab[n].userhl - 1];
    }
    screen_puts(p, row, col, curattr);

    if (wp == NULL)
    {
        /* Fill the TabPageIdxs[] array for clicking in the tab pagesline. */
        col = 0;
        len = 0;
        p = buf;
        fillchar = 0;
        for (n = 0; tabtab[n].start != NULL; n++)
        {
            len += vim_strnsize(p, (int)(tabtab[n].start - p));
            while (col < len)
                TabPageIdxs[col++] = fillchar;
            p = tabtab[n].start;
            fillchar = tabtab[n].userhl;
        }
        while (col < Columns)
            TabPageIdxs[col++] = fillchar;
    }
}

#endif /* FEAT_STL_OPT */

/*
 * Output a single character directly to the screen and update ScreenLines.
 */
    void
screen_putchar(c, row, col, attr)
    int     c;
    int     row, col;
    int     attr;
{
#ifdef FEAT_MBYTE
    char_u      buf[MB_MAXBYTES + 1];

    buf[(*mb_char2bytes)(c, buf)] = NUL;
#else
    char_u      buf[2];

    buf[0] = c;
    buf[1] = NUL;
#endif
    screen_puts(buf, row, col, attr);
}

/*
 * Get a single character directly from ScreenLines into "bytes[]".
 * Also return its attribute in *attrp;
 */
    void
screen_getbytes(row, col, bytes, attrp)
    int     row, col;
    char_u  *bytes;
    int     *attrp;
{
    unsigned off;

    /* safety check */
    if (ScreenLines != NULL && row < screen_Rows && col < screen_Columns)
    {
        off = LineOffset[row] + col;
        *attrp = ScreenAttrs[off];
        bytes[0] = ScreenLines[off];
        bytes[1] = NUL;

#ifdef FEAT_MBYTE
        if (enc_utf8 && ScreenLinesUC[off] != 0)
            bytes[utfc_char2bytes(off, bytes)] = NUL;
        else if (enc_dbcs == DBCS_JPNU && ScreenLines[off] == 0x8e)
        {
            bytes[0] = ScreenLines[off];
            bytes[1] = ScreenLines2[off];
            bytes[2] = NUL;
        }
        else if (enc_dbcs && MB_BYTE2LEN(bytes[0]) > 1)
        {
            bytes[1] = ScreenLines[off + 1];
            bytes[2] = NUL;
        }
#endif
    }
}

#ifdef FEAT_MBYTE
static int screen_comp_differs __ARGS((int, int*));

/*
 * Return TRUE if composing characters for screen posn "off" differs from
 * composing characters in "u8cc".
 */
    static int
screen_comp_differs(off, u8cc)
    int     off;
    int     *u8cc;
{
    int     i;

    for (i = 0; i < Screen_mco; ++i)
    {
        if (ScreenLinesC[i][off] != (u8char_T)u8cc[i])
            return TRUE;
        if (u8cc[i] == 0)
            break;
    }
    return FALSE;
}
#endif

/*
 * Put string '*text' on the screen at position 'row' and 'col', with
 * attributes 'attr', and update ScreenLines[] and ScreenAttrs[].
 * Note: only outputs within one row, message is truncated at screen boundary!
 * Note: if ScreenLines[], row and/or col is invalid, nothing is done.
 */
    void
screen_puts(text, row, col, attr)
    char_u      *text;
    int         row;
    int         col;
    int         attr;
{
    screen_puts_len(text, -1, row, col, attr);
}

/*
 * Like screen_puts(), but output "text[len]".  When "len" is -1 output up to
 * a NUL.
 */
    void
screen_puts_len(text, len, row, col, attr)
    char_u      *text;
    int         len;
    int         row;
    int         col;
    int         attr;
{
    unsigned    off;
    char_u      *ptr = text;
    int         c;
#ifdef FEAT_MBYTE
    unsigned    max_off;
    int         mbyte_blen = 1;
    int         mbyte_cells = 1;
    int         u8c = 0;
    int         u8cc[MAX_MCO];
    int         clear_next_cell = FALSE;
# ifdef FEAT_ARABIC
    int         prev_c = 0;             /* previous Arabic character */
    int         pc, nc, nc1;
    int         pcc[MAX_MCO];
# endif
#endif
#if defined(FEAT_MBYTE) || defined(FEAT_GUI) || defined(UNIX)
    int         force_redraw_this;
    int         force_redraw_next = FALSE;
#endif
    int         need_redraw;

    if (ScreenLines == NULL || row >= screen_Rows)      /* safety check */
        return;
    off = LineOffset[row] + col;

#ifdef FEAT_MBYTE
    /* When drawing over the right halve of a double-wide char clear out the
     * left halve.  Only needed in a terminal. */
    if (has_mbyte && col > 0 && col < screen_Columns
# ifdef FEAT_GUI
            && !gui.in_use
# endif
            && mb_fix_col(col, row) != col)
    {
        ScreenLines[off - 1] = ' ';
        ScreenAttrs[off - 1] = 0;
        if (enc_utf8)
        {
            ScreenLinesUC[off - 1] = 0;
            ScreenLinesC[0][off - 1] = 0;
        }
        /* redraw the previous cell, make it empty */
        screen_char(off - 1, row, col - 1);
        /* force the cell at "col" to be redrawn */
        force_redraw_next = TRUE;
    }
#endif

#ifdef FEAT_MBYTE
    max_off = LineOffset[row] + screen_Columns;
#endif
    while (col < screen_Columns
            && (len < 0 || (int)(ptr - text) < len)
            && *ptr != NUL)
    {
        c = *ptr;
#ifdef FEAT_MBYTE
        /* check if this is the first byte of a multibyte */
        if (has_mbyte)
        {
            if (enc_utf8 && len > 0)
                mbyte_blen = utfc_ptr2len_len(ptr, (int)((text + len) - ptr));
            else
                mbyte_blen = (*mb_ptr2len)(ptr);
            if (enc_dbcs == DBCS_JPNU && c == 0x8e)
                mbyte_cells = 1;
            else if (enc_dbcs != 0)
                mbyte_cells = mbyte_blen;
            else        /* enc_utf8 */
            {
                if (len >= 0)
                    u8c = utfc_ptr2char_len(ptr, u8cc,
                                                   (int)((text + len) - ptr));
                else
                    u8c = utfc_ptr2char(ptr, u8cc);
                mbyte_cells = utf_char2cells(u8c);
# ifdef UNICODE16
                /* Non-BMP character: display as ? or fullwidth ?. */
                if (u8c >= 0x10000)
                {
                    u8c = (mbyte_cells == 2) ? 0xff1f : (int)'?';
                    if (attr == 0)
                        attr = hl_attr(HLF_8);
                }
# endif
# ifdef FEAT_ARABIC
                if (p_arshape && !p_tbidi && ARABIC_CHAR(u8c))
                {
                    /* Do Arabic shaping. */
                    if (len >= 0 && (int)(ptr - text) + mbyte_blen >= len)
                    {
                        /* Past end of string to be displayed. */
                        nc = NUL;
                        nc1 = NUL;
                    }
                    else
                    {
                        nc = utfc_ptr2char(ptr + mbyte_blen, pcc);
                        nc1 = pcc[0];
                    }
                    pc = prev_c;
                    prev_c = u8c;
                    u8c = arabic_shape(u8c, &c, &u8cc[0], nc, nc1, pc);
                }
                else
                    prev_c = u8c;
# endif
            }
        }
#endif

#if defined(FEAT_MBYTE) || defined(FEAT_GUI) || defined(UNIX)
        force_redraw_this = force_redraw_next;
        force_redraw_next = FALSE;
#endif

        need_redraw = ScreenLines[off] != c
#ifdef FEAT_MBYTE
                || (mbyte_cells == 2
                    && ScreenLines[off + 1] != (enc_dbcs ? ptr[1] : 0))
                || (enc_dbcs == DBCS_JPNU
                    && c == 0x8e
                    && ScreenLines2[off] != ptr[1])
                || (enc_utf8
                    && (ScreenLinesUC[off] != (u8char_T)(c >= 0x80 ? u8c : 0)
                        || screen_comp_differs(off, u8cc)))
#endif
                || ScreenAttrs[off] != attr
                || exmode_active;

        if (need_redraw
#if defined(FEAT_MBYTE) || defined(FEAT_GUI) || defined(UNIX)
                || force_redraw_this
#endif
                )
        {
#if defined(FEAT_GUI) || defined(UNIX)
            /* The bold trick makes a single row of pixels appear in the next
             * character.  When a bold character is removed, the next
             * character should be redrawn too.  This happens for our own GUI
             * and for some xterms. */
            if (need_redraw && ScreenLines[off] != ' ' && (
# ifdef FEAT_GUI
                    gui.in_use
# endif
# if defined(FEAT_GUI) && defined(UNIX)
                    ||
# endif
# ifdef UNIX
                    term_is_xterm
# endif
                    ))
            {
                int     n = ScreenAttrs[off];

                if (n > HL_ALL)
                    n = syn_attr2attr(n);
                if (n & HL_BOLD)
                    force_redraw_next = TRUE;
            }
#endif
#ifdef FEAT_MBYTE
            /* When at the end of the text and overwriting a two-cell
             * character with a one-cell character, need to clear the next
             * cell.  Also when overwriting the left halve of a two-cell char
             * with the right halve of a two-cell char.  Do this only once
             * (mb_off2cells() may return 2 on the right halve). */
            if (clear_next_cell)
                clear_next_cell = FALSE;
            else if (has_mbyte
                    && (len < 0 ? ptr[mbyte_blen] == NUL
                                             : ptr + mbyte_blen >= text + len)
                    && ((mbyte_cells == 1 && (*mb_off2cells)(off, max_off) > 1)
                        || (mbyte_cells == 2
                            && (*mb_off2cells)(off, max_off) == 1
                            && (*mb_off2cells)(off + 1, max_off) > 1)))
                clear_next_cell = TRUE;

            /* Make sure we never leave a second byte of a double-byte behind,
             * it confuses mb_off2cells(). */
            if (enc_dbcs
                    && ((mbyte_cells == 1 && (*mb_off2cells)(off, max_off) > 1)
                        || (mbyte_cells == 2
                            && (*mb_off2cells)(off, max_off) == 1
                            && (*mb_off2cells)(off + 1, max_off) > 1)))
                ScreenLines[off + mbyte_blen] = 0;
#endif
            ScreenLines[off] = c;
            ScreenAttrs[off] = attr;
#ifdef FEAT_MBYTE
            if (enc_utf8)
            {
                if (c < 0x80 && u8cc[0] == 0)
                    ScreenLinesUC[off] = 0;
                else
                {
                    int     i;

                    ScreenLinesUC[off] = u8c;
                    for (i = 0; i < Screen_mco; ++i)
                    {
                        ScreenLinesC[i][off] = u8cc[i];
                        if (u8cc[i] == 0)
                            break;
                    }
                }
                if (mbyte_cells == 2)
                {
                    ScreenLines[off + 1] = 0;
                    ScreenAttrs[off + 1] = attr;
                }
                screen_char(off, row, col);
            }
            else if (mbyte_cells == 2)
            {
                ScreenLines[off + 1] = ptr[1];
                ScreenAttrs[off + 1] = attr;
                screen_char_2(off, row, col);
            }
            else if (enc_dbcs == DBCS_JPNU && c == 0x8e)
            {
                ScreenLines2[off] = ptr[1];
                screen_char(off, row, col);
            }
            else
#endif
                screen_char(off, row, col);
        }
#ifdef FEAT_MBYTE
        if (has_mbyte)
        {
            off += mbyte_cells;
            col += mbyte_cells;
            ptr += mbyte_blen;
            if (clear_next_cell)
                ptr = (char_u *)" ";
        }
        else
#endif
        {
            ++off;
            ++col;
            ++ptr;
        }
    }

#if defined(FEAT_MBYTE) || defined(FEAT_GUI) || defined(UNIX)
    /* If we detected the next character needs to be redrawn, but the text
     * doesn't extend up to there, update the character here. */
    if (force_redraw_next && col < screen_Columns)
    {
# ifdef FEAT_MBYTE
        if (enc_dbcs != 0 && dbcs_off2cells(off, max_off) > 1)
            screen_char_2(off, row, col);
        else
# endif
            screen_char(off, row, col);
    }
#endif
}

#ifdef FEAT_SEARCH_EXTRA
/*
 * Prepare for 'hlsearch' highlighting.
 */
    static void
start_search_hl()
{
    if (p_hls && !no_hlsearch)
    {
        last_pat_prog(&search_hl.rm);
        search_hl.attr = hl_attr(HLF_L);
# ifdef FEAT_RELTIME
        /* Set the time limit to 'redrawtime'. */
        profile_setlimit(p_rdt, &search_hl.tm);
# endif
    }
}

/*
 * Clean up for 'hlsearch' highlighting.
 */
    static void
end_search_hl()
{
    if (search_hl.rm.regprog != NULL)
    {
        vim_free(search_hl.rm.regprog);
        search_hl.rm.regprog = NULL;
    }
}

/*
 * Advance to the match in window "wp" line "lnum" or past it.
 */
    static void
prepare_search_hl(wp, lnum)
    win_T       *wp;
    linenr_T    lnum;
{
    matchitem_T *cur;           /* points to the match list */
    match_T     *shl;           /* points to search_hl or a match */
    int         shl_flag;       /* flag to indicate whether search_hl
                                   has been processed or not */
    int         n;

    /*
     * When using a multi-line pattern, start searching at the top
     * of the window or just after a closed fold.
     * Do this both for search_hl and the match list.
     */
    cur = wp->w_match_head;
    shl_flag = FALSE;
    while (cur != NULL || shl_flag == FALSE)
    {
        if (shl_flag == FALSE)
        {
            shl = &search_hl;
            shl_flag = TRUE;
        }
        else
            shl = &cur->hl;
        if (shl->rm.regprog != NULL
                && shl->lnum == 0
                && re_multiline(shl->rm.regprog))
        {
            if (shl->first_lnum == 0)
            {
# ifdef FEAT_FOLDING
                for (shl->first_lnum = lnum;
                           shl->first_lnum > wp->w_topline; --shl->first_lnum)
                    if (hasFoldingWin(wp, shl->first_lnum - 1,
                                                      NULL, NULL, TRUE, NULL))
                        break;
# else
                shl->first_lnum = wp->w_topline;
# endif
            }
            n = 0;
            while (shl->first_lnum < lnum && shl->rm.regprog != NULL)
            {
                next_search_hl(wp, shl, shl->first_lnum, (colnr_T)n);
                if (shl->lnum != 0)
                {
                    shl->first_lnum = shl->lnum
                                    + shl->rm.endpos[0].lnum
                                    - shl->rm.startpos[0].lnum;
                    n = shl->rm.endpos[0].col;
                }
                else
                {
                    ++shl->first_lnum;
                    n = 0;
                }
            }
        }
        if (shl != &search_hl && cur != NULL)
            cur = cur->next;
    }
}

/*
 * Search for a next 'hlsearch' or match.
 * Uses shl->buf.
 * Sets shl->lnum and shl->rm contents.
 * Note: Assumes a previous match is always before "lnum", unless
 * shl->lnum is zero.
 * Careful: Any pointers for buffer lines will become invalid.
 */
    static void
next_search_hl(win, shl, lnum, mincol)
    win_T       *win;
    match_T     *shl;           /* points to search_hl or a match */
    linenr_T    lnum;
    colnr_T     mincol;         /* minimal column for a match */
{
    linenr_T    l;
    colnr_T     matchcol;
    long        nmatched;

    if (shl->lnum != 0)
    {
        /* Check for three situations:
         * 1. If the "lnum" is below a previous match, start a new search.
         * 2. If the previous match includes "mincol", use it.
         * 3. Continue after the previous match.
         */
        l = shl->lnum + shl->rm.endpos[0].lnum - shl->rm.startpos[0].lnum;
        if (lnum > l)
            shl->lnum = 0;
        else if (lnum < l || shl->rm.endpos[0].col > mincol)
            return;
    }

    /*
     * Repeat searching for a match until one is found that includes "mincol"
     * or none is found in this line.
     */
    called_emsg = FALSE;
    for (;;)
    {
#ifdef FEAT_RELTIME
        /* Stop searching after passing the time limit. */
        if (profile_passed_limit(&(shl->tm)))
        {
            shl->lnum = 0;              /* no match found in time */
            break;
        }
#endif
        /* Three situations:
         * 1. No useful previous match: search from start of line.
         * 2. Not Vi compatible or empty match: continue at next character.
         *    Break the loop if this is beyond the end of the line.
         * 3. Vi compatible searching: continue at end of previous match.
         */
        if (shl->lnum == 0)
            matchcol = 0;
        else if (vim_strchr(p_cpo, CPO_SEARCH) == NULL
                || (shl->rm.endpos[0].lnum == 0
                    && shl->rm.endpos[0].col <= shl->rm.startpos[0].col))
        {
            char_u      *ml;

            matchcol = shl->rm.startpos[0].col;
            ml = ml_get_buf(shl->buf, lnum, FALSE) + matchcol;
            if (*ml == NUL)
            {
                ++matchcol;
                shl->lnum = 0;
                break;
            }
#ifdef FEAT_MBYTE
            if (has_mbyte)
                matchcol += mb_ptr2len(ml);
            else
#endif
                ++matchcol;
        }
        else
            matchcol = shl->rm.endpos[0].col;

        shl->lnum = lnum;
        nmatched = vim_regexec_multi(&shl->rm, win, shl->buf, lnum, matchcol,
#ifdef FEAT_RELTIME
                &(shl->tm)
#else
                NULL
#endif
                );
        if (called_emsg)
        {
            /* Error while handling regexp: stop using this regexp. */
            if (shl == &search_hl)
            {
                /* don't free regprog in the match list, it's a copy */
                vim_free(shl->rm.regprog);
                no_hlsearch = TRUE;
            }
            shl->rm.regprog = NULL;
            shl->lnum = 0;
            got_int = FALSE;  /* avoid the "Type :quit to exit Vim" message */
            break;
        }
        if (nmatched == 0)
        {
            shl->lnum = 0;              /* no match found */
            break;
        }
        if (shl->rm.startpos[0].lnum > 0
                || shl->rm.startpos[0].col >= mincol
                || nmatched > 1
                || shl->rm.endpos[0].col > mincol)
        {
            shl->lnum += shl->rm.startpos[0].lnum;
            break;                      /* useful match found */
        }
    }
}
#endif

      static void
screen_start_highlight(attr)
      int       attr;
{
    attrentry_T *aep = NULL;

    screen_attr = attr;
    if (full_screen
#ifdef WIN3264
                    && termcap_active
#endif
                                       )
    {
#ifdef FEAT_GUI
        if (gui.in_use)
        {
            char        buf[20];

            /* The GUI handles this internally. */
            sprintf(buf, IF_EB("\033|%dh", ESC_STR "|%dh"), attr);
            OUT_STR(buf);
        }
        else
#endif
        {
            if (attr > HL_ALL)                          /* special HL attr. */
            {
                if (t_colors > 1)
                    aep = syn_cterm_attr2entry(attr);
                else
                    aep = syn_term_attr2entry(attr);
                if (aep == NULL)            /* did ":syntax clear" */
                    attr = 0;
                else
                    attr = aep->ae_attr;
            }
            if ((attr & HL_BOLD) && T_MD != NULL)       /* bold */
                out_str(T_MD);
            else if (aep != NULL && t_colors > 1 && aep->ae_u.cterm.fg_color
                                                      && cterm_normal_fg_bold)
                /* If the Normal FG color has BOLD attribute and the new HL
                 * has a FG color defined, clear BOLD. */
                out_str(T_ME);
            if ((attr & HL_STANDOUT) && T_SO != NULL)   /* standout */
                out_str(T_SO);
            if ((attr & (HL_UNDERLINE | HL_UNDERCURL)) && T_US != NULL)
                                                   /* underline or undercurl */
                out_str(T_US);
            if ((attr & HL_ITALIC) && T_CZH != NULL)    /* italic */
                out_str(T_CZH);
            if ((attr & HL_INVERSE) && T_MR != NULL)    /* inverse (reverse) */
                out_str(T_MR);

            /*
             * Output the color or start string after bold etc., in case the
             * bold etc. override the color setting.
             */
            if (aep != NULL)
            {
                if (t_colors > 1)
                {
                    if (aep->ae_u.cterm.fg_color)
                        term_fg_color(aep->ae_u.cterm.fg_color - 1);
                    if (aep->ae_u.cterm.bg_color)
                        term_bg_color(aep->ae_u.cterm.bg_color - 1);
                }
                else
                {
                    if (aep->ae_u.term.start != NULL)
                        out_str(aep->ae_u.term.start);
                }
            }
        }
    }
}

      void
screen_stop_highlight()
{
    int     do_ME = FALSE;          /* output T_ME code */

    if (screen_attr != 0
#ifdef WIN3264
                        && termcap_active
#endif
                                           )
    {
#ifdef FEAT_GUI
        if (gui.in_use)
        {
            char        buf[20];

            /* use internal GUI code */
            sprintf(buf, IF_EB("\033|%dH", ESC_STR "|%dH"), screen_attr);
            OUT_STR(buf);
        }
        else
#endif
        {
            if (screen_attr > HL_ALL)                   /* special HL attr. */
            {
                attrentry_T *aep;

                if (t_colors > 1)
                {
                    /*
                     * Assume that t_me restores the original colors!
                     */
                    aep = syn_cterm_attr2entry(screen_attr);
                    if (aep != NULL && (aep->ae_u.cterm.fg_color
                                                 || aep->ae_u.cterm.bg_color))
                        do_ME = TRUE;
                }
                else
                {
                    aep = syn_term_attr2entry(screen_attr);
                    if (aep != NULL && aep->ae_u.term.stop != NULL)
                    {
                        if (STRCMP(aep->ae_u.term.stop, T_ME) == 0)
                            do_ME = TRUE;
                        else
                            out_str(aep->ae_u.term.stop);
                    }
                }
                if (aep == NULL)            /* did ":syntax clear" */
                    screen_attr = 0;
                else
                    screen_attr = aep->ae_attr;
            }

            /*
             * Often all ending-codes are equal to T_ME.  Avoid outputting the
             * same sequence several times.
             */
            if (screen_attr & HL_STANDOUT)
            {
                if (STRCMP(T_SE, T_ME) == 0)
                    do_ME = TRUE;
                else
                    out_str(T_SE);
            }
            if (screen_attr & (HL_UNDERLINE | HL_UNDERCURL))
            {
                if (STRCMP(T_UE, T_ME) == 0)
                    do_ME = TRUE;
                else
                    out_str(T_UE);
            }
            if (screen_attr & HL_ITALIC)
            {
                if (STRCMP(T_CZR, T_ME) == 0)
                    do_ME = TRUE;
                else
                    out_str(T_CZR);
            }
            if (do_ME || (screen_attr & (HL_BOLD | HL_INVERSE)))
                out_str(T_ME);

            if (t_colors > 1)
            {
                /* set Normal cterm colors */
                if (cterm_normal_fg_color != 0)
                    term_fg_color(cterm_normal_fg_color - 1);
                if (cterm_normal_bg_color != 0)
                    term_bg_color(cterm_normal_bg_color - 1);
                if (cterm_normal_fg_bold)
                    out_str(T_MD);
            }
        }
    }
    screen_attr = 0;
}

/*
 * Reset the colors for a cterm.  Used when leaving Vim.
 * The machine specific code may override this again.
 */
    void
reset_cterm_colors()
{
    if (t_colors > 1)
    {
        /* set Normal cterm colors */
        if (cterm_normal_fg_color > 0 || cterm_normal_bg_color > 0)
        {
            out_str(T_OP);
            screen_attr = -1;
        }
        if (cterm_normal_fg_bold)
        {
            out_str(T_ME);
            screen_attr = -1;
        }
    }
}

/*
 * Put character ScreenLines["off"] on the screen at position "row" and "col",
 * using the attributes from ScreenAttrs["off"].
 */
    static void
screen_char(off, row, col)
    unsigned    off;
    int         row;
    int         col;
{
    int         attr;

    /* Check for illegal values, just in case (could happen just after
     * resizing). */
    if (row >= screen_Rows || col >= screen_Columns)
        return;

    /* Outputting the last character on the screen may scrollup the screen.
     * Don't to it!  Mark the character invalid (update it when scrolled up) */
    if (row == screen_Rows - 1 && col == screen_Columns - 1
#ifdef FEAT_RIGHTLEFT
            /* account for first command-line character in rightleft mode */
            && !cmdmsg_rl
#endif
       )
    {
        ScreenAttrs[off] = (sattr_T)-1;
        return;
    }

    /*
     * Stop highlighting first, so it's easier to move the cursor.
     */
#if defined(FEAT_CLIPBOARD) || defined(FEAT_VERTSPLIT)
    if (screen_char_attr != 0)
        attr = screen_char_attr;
    else
#endif
        attr = ScreenAttrs[off];
    if (screen_attr != attr)
        screen_stop_highlight();

    windgoto(row, col);

    if (screen_attr != attr)
        screen_start_highlight(attr);

#ifdef FEAT_MBYTE
    if (enc_utf8 && ScreenLinesUC[off] != 0)
    {
        char_u      buf[MB_MAXBYTES + 1];

        /* Convert UTF-8 character to bytes and write it. */

        buf[utfc_char2bytes(off, buf)] = NUL;

        out_str(buf);
        if (utf_char2cells(ScreenLinesUC[off]) > 1)
            ++screen_cur_col;
    }
    else
#endif
    {
#ifdef FEAT_MBYTE
        out_flush_check();
#endif
        out_char(ScreenLines[off]);
#ifdef FEAT_MBYTE
        /* double-byte character in single-width cell */
        if (enc_dbcs == DBCS_JPNU && ScreenLines[off] == 0x8e)
            out_char(ScreenLines2[off]);
#endif
    }

    screen_cur_col++;
}

#ifdef FEAT_MBYTE

/*
 * Used for enc_dbcs only: Put one double-wide character at ScreenLines["off"]
 * on the screen at position 'row' and 'col'.
 * The attributes of the first byte is used for all.  This is required to
 * output the two bytes of a double-byte character with nothing in between.
 */
    static void
screen_char_2(off, row, col)
    unsigned    off;
    int         row;
    int         col;
{
    /* Check for illegal values (could be wrong when screen was resized). */
    if (off + 1 >= (unsigned)(screen_Rows * screen_Columns))
        return;

    /* Outputting the last character on the screen may scrollup the screen.
     * Don't to it!  Mark the character invalid (update it when scrolled up) */
    if (row == screen_Rows - 1 && col >= screen_Columns - 2)
    {
        ScreenAttrs[off] = (sattr_T)-1;
        return;
    }

    /* Output the first byte normally (positions the cursor), then write the
     * second byte directly. */
    screen_char(off, row, col);
    out_char(ScreenLines[off + 1]);
    ++screen_cur_col;
}
#endif

#if defined(FEAT_CLIPBOARD) || defined(FEAT_VERTSPLIT) || defined(PROTO)
/*
 * Draw a rectangle of the screen, inverted when "invert" is TRUE.
 * This uses the contents of ScreenLines[] and doesn't change it.
 */
    void
screen_draw_rectangle(row, col, height, width, invert)
    int         row;
    int         col;
    int         height;
    int         width;
    int         invert;
{
    int         r, c;
    int         off;
#ifdef FEAT_MBYTE
    int         max_off;
#endif

    /* Can't use ScreenLines unless initialized */
    if (ScreenLines == NULL)
        return;

    if (invert)
        screen_char_attr = HL_INVERSE;
    for (r = row; r < row + height; ++r)
    {
        off = LineOffset[r];
#ifdef FEAT_MBYTE
        max_off = off + screen_Columns;
#endif
        for (c = col; c < col + width; ++c)
        {
#ifdef FEAT_MBYTE
            if (enc_dbcs != 0 && dbcs_off2cells(off + c, max_off) > 1)
            {
                screen_char_2(off + c, r, c);
                ++c;
            }
            else
#endif
            {
                screen_char(off + c, r, c);
#ifdef FEAT_MBYTE
                if (utf_off2cells(off + c, max_off) > 1)
                    ++c;
#endif
            }
        }
    }
    screen_char_attr = 0;
}
#endif

#ifdef FEAT_VERTSPLIT
/*
 * Redraw the characters for a vertically split window.
 */
    static void
redraw_block(row, end, wp)
    int         row;
    int         end;
    win_T       *wp;
{
    int         col;
    int         width;

# ifdef FEAT_CLIPBOARD
    clip_may_clear_selection(row, end - 1);
# endif

    if (wp == NULL)
    {
        col = 0;
        width = Columns;
    }
    else
    {
        col = wp->w_wincol;
        width = wp->w_width;
    }
    screen_draw_rectangle(row, col, end - row, width, FALSE);
}
#endif

/*
 * Fill the screen from 'start_row' to 'end_row', from 'start_col' to 'end_col'
 * with character 'c1' in first column followed by 'c2' in the other columns.
 * Use attributes 'attr'.
 */
    void
screen_fill(start_row, end_row, start_col, end_col, c1, c2, attr)
    int     start_row, end_row;
    int     start_col, end_col;
    int     c1, c2;
    int     attr;
{
    int             row;
    int             col;
    int             off;
    int             end_off;
    int             did_delete;
    int             c;
    int             norm_term;
#if defined(FEAT_GUI) || defined(UNIX)
    int             force_next = FALSE;
#endif

    if (end_row > screen_Rows)          /* safety check */
        end_row = screen_Rows;
    if (end_col > screen_Columns)       /* safety check */
        end_col = screen_Columns;
    if (ScreenLines == NULL
            || start_row >= end_row
            || start_col >= end_col)    /* nothing to do */
        return;

    /* it's a "normal" terminal when not in a GUI or cterm */
    norm_term = (
#ifdef FEAT_GUI
            !gui.in_use &&
#endif
                            t_colors <= 1);
    for (row = start_row; row < end_row; ++row)
    {
#ifdef FEAT_MBYTE
        if (has_mbyte
# ifdef FEAT_GUI
                && !gui.in_use
# endif
           )
        {
            /* When drawing over the right halve of a double-wide char clear
             * out the left halve.  When drawing over the left halve of a
             * double wide-char clear out the right halve.  Only needed in a
             * terminal. */
            if (start_col > 0 && mb_fix_col(start_col, row) != start_col)
                screen_puts_len((char_u *)" ", 1, row, start_col - 1, 0);
            if (end_col < screen_Columns && mb_fix_col(end_col, row) != end_col)
                screen_puts_len((char_u *)" ", 1, row, end_col, 0);
        }
#endif
        /*
         * Try to use delete-line termcap code, when no attributes or in a
         * "normal" terminal, where a bold/italic space is just a
         * space.
         */
        did_delete = FALSE;
        if (c2 == ' '
                && end_col == Columns
                && can_clear(T_CE)
                && (attr == 0
                    || (norm_term
                        && attr <= HL_ALL
                        && ((attr & ~(HL_BOLD | HL_ITALIC)) == 0))))
        {
            /*
             * check if we really need to clear something
             */
            col = start_col;
            if (c1 != ' ')                      /* don't clear first char */
                ++col;

            off = LineOffset[row] + col;
            end_off = LineOffset[row] + end_col;

            /* skip blanks (used often, keep it fast!) */
#ifdef FEAT_MBYTE
            if (enc_utf8)
                while (off < end_off && ScreenLines[off] == ' '
                          && ScreenAttrs[off] == 0 && ScreenLinesUC[off] == 0)
                    ++off;
            else
#endif
                while (off < end_off && ScreenLines[off] == ' '
                                                     && ScreenAttrs[off] == 0)
                    ++off;
            if (off < end_off)          /* something to be cleared */
            {
                col = off - LineOffset[row];
                screen_stop_highlight();
                term_windgoto(row, col);/* clear rest of this screen line */
                out_str(T_CE);
                screen_start();         /* don't know where cursor is now */
                col = end_col - col;
                while (col--)           /* clear chars in ScreenLines */
                {
                    ScreenLines[off] = ' ';
#ifdef FEAT_MBYTE
                    if (enc_utf8)
                        ScreenLinesUC[off] = 0;
#endif
                    ScreenAttrs[off] = 0;
                    ++off;
                }
            }
            did_delete = TRUE;          /* the chars are cleared now */
        }

        off = LineOffset[row] + start_col;
        c = c1;
        for (col = start_col; col < end_col; ++col)
        {
            if (ScreenLines[off] != c
#ifdef FEAT_MBYTE
                    || (enc_utf8 && (int)ScreenLinesUC[off]
                                                       != (c >= 0x80 ? c : 0))
#endif
                    || ScreenAttrs[off] != attr
#if defined(FEAT_GUI) || defined(UNIX)
                    || force_next
#endif
                    )
            {
#if defined(FEAT_GUI) || defined(UNIX)
                /* The bold trick may make a single row of pixels appear in
                 * the next character.  When a bold character is removed, the
                 * next character should be redrawn too.  This happens for our
                 * own GUI and for some xterms.  */
                if (
# ifdef FEAT_GUI
                        gui.in_use
# endif
# if defined(FEAT_GUI) && defined(UNIX)
                        ||
# endif
# ifdef UNIX
                        term_is_xterm
# endif
                   )
                {
                    if (ScreenLines[off] != ' '
                            && (ScreenAttrs[off] > HL_ALL
                                || ScreenAttrs[off] & HL_BOLD))
                        force_next = TRUE;
                    else
                        force_next = FALSE;
                }
#endif
                ScreenLines[off] = c;
#ifdef FEAT_MBYTE
                if (enc_utf8)
                {
                    if (c >= 0x80)
                    {
                        ScreenLinesUC[off] = c;
                        ScreenLinesC[0][off] = 0;
                    }
                    else
                        ScreenLinesUC[off] = 0;
                }
#endif
                ScreenAttrs[off] = attr;
                if (!did_delete || c != ' ')
                    screen_char(off, row, col);
            }
            ++off;
            if (col == start_col)
            {
                if (did_delete)
                    break;
                c = c2;
            }
        }
        if (end_col == Columns)
            LineWraps[row] = FALSE;
        if (row == Rows - 1)            /* overwritten the command line */
        {
            redraw_cmdline = TRUE;
            if (c1 == ' ' && c2 == ' ')
                clear_cmdline = FALSE;  /* command line has been cleared */
            if (start_col == 0)
                mode_displayed = FALSE; /* mode cleared or overwritten */
        }
    }
}

/*
 * Check if there should be a delay.  Used before clearing or redrawing the
 * screen or the command line.
 */
    void
check_for_delay(check_msg_scroll)
    int     check_msg_scroll;
{
    if ((emsg_on_display || (check_msg_scroll && msg_scroll))
            && !did_wait_return
            && emsg_silent == 0)
    {
        out_flush();
        ui_delay(1000L, TRUE);
        emsg_on_display = FALSE;
        if (check_msg_scroll)
            msg_scroll = FALSE;
    }
}

/*
 * screen_valid -  allocate screen buffers if size changed
 *   If "clear" is TRUE: clear screen if it has been resized.
 *      Returns TRUE if there is a valid screen to write to.
 *      Returns FALSE when starting up and screen not initialized yet.
 */
    int
screen_valid(clear)
    int     clear;
{
    screenalloc(clear);     /* allocate screen buffers if size changed */
    return (ScreenLines != NULL);
}

/*
 * Resize the shell to Rows and Columns.
 * Allocate ScreenLines[] and associated items.
 *
 * There may be some time between setting Rows and Columns and (re)allocating
 * ScreenLines[].  This happens when starting up and when (manually) changing
 * the shell size.  Always use screen_Rows and screen_Columns to access items
 * in ScreenLines[].  Use Rows and Columns for positioning text etc. where the
 * final size of the shell is needed.
 */
    void
screenalloc(clear)
    int     clear;
{
    int             new_row, old_row;
#ifdef FEAT_GUI
    int             old_Rows;
#endif
    win_T           *wp;
    int             outofmem = FALSE;
    int             len;
    schar_T         *new_ScreenLines;
#ifdef FEAT_MBYTE
    u8char_T        *new_ScreenLinesUC = NULL;
    u8char_T        *new_ScreenLinesC[MAX_MCO];
    schar_T         *new_ScreenLines2 = NULL;
    int             i;
#endif
    sattr_T         *new_ScreenAttrs;
    unsigned        *new_LineOffset;
    char_u          *new_LineWraps;
#ifdef FEAT_WINDOWS
    short           *new_TabPageIdxs;
    tabpage_T       *tp;
#endif
    static int      entered = FALSE;            /* avoid recursiveness */
    static int      done_outofmem_msg = FALSE;  /* did outofmem message */
#ifdef FEAT_AUTOCMD
    int             retry_count = 0;

retry:
#endif
    /*
     * Allocation of the screen buffers is done only when the size changes and
     * when Rows and Columns have been set and we have started doing full
     * screen stuff.
     */
    if ((ScreenLines != NULL
                && Rows == screen_Rows
                && Columns == screen_Columns
#ifdef FEAT_MBYTE
                && enc_utf8 == (ScreenLinesUC != NULL)
                && (enc_dbcs == DBCS_JPNU) == (ScreenLines2 != NULL)
                && p_mco == Screen_mco
#endif
                )
            || Rows == 0
            || Columns == 0
            || (!full_screen && ScreenLines == NULL))
        return;

    /*
     * It's possible that we produce an out-of-memory message below, which
     * will cause this function to be called again.  To break the loop, just
     * return here.
     */
    if (entered)
        return;
    entered = TRUE;

    /*
     * Note that the window sizes are updated before reallocating the arrays,
     * thus we must not redraw here!
     */
    ++RedrawingDisabled;

    win_new_shellsize();    /* fit the windows in the new sized shell */

    comp_col();         /* recompute columns for shown command and ruler */

    /*
     * We're changing the size of the screen.
     * - Allocate new arrays for ScreenLines and ScreenAttrs.
     * - Move lines from the old arrays into the new arrays, clear extra
     *   lines (unless the screen is going to be cleared).
     * - Free the old arrays.
     *
     * If anything fails, make ScreenLines NULL, so we don't do anything!
     * Continuing with the old ScreenLines may result in a crash, because the
     * size is wrong.
     */
    FOR_ALL_TAB_WINDOWS(tp, wp)
        win_free_lsize(wp);

    new_ScreenLines = (schar_T *)lalloc((long_u)(
                              (Rows + 1) * Columns * sizeof(schar_T)), FALSE);
#ifdef FEAT_MBYTE
    vim_memset(new_ScreenLinesC, 0, sizeof(u8char_T) * MAX_MCO);
    if (enc_utf8)
    {
        new_ScreenLinesUC = (u8char_T *)lalloc((long_u)(
                             (Rows + 1) * Columns * sizeof(u8char_T)), FALSE);
        for (i = 0; i < p_mco; ++i)
            new_ScreenLinesC[i] = (u8char_T *)lalloc((long_u)(
                             (Rows + 1) * Columns * sizeof(u8char_T)), FALSE);
    }
    if (enc_dbcs == DBCS_JPNU)
        new_ScreenLines2 = (schar_T *)lalloc((long_u)(
                             (Rows + 1) * Columns * sizeof(schar_T)), FALSE);
#endif
    new_ScreenAttrs = (sattr_T *)lalloc((long_u)(
                              (Rows + 1) * Columns * sizeof(sattr_T)), FALSE);
    new_LineOffset = (unsigned *)lalloc((long_u)(
                                         Rows * sizeof(unsigned)), FALSE);
    new_LineWraps = (char_u *)lalloc((long_u)(Rows * sizeof(char_u)), FALSE);
#ifdef FEAT_WINDOWS
    new_TabPageIdxs = (short *)lalloc((long_u)(Columns * sizeof(short)), FALSE);
#endif

    FOR_ALL_TAB_WINDOWS(tp, wp)
    {
        if (win_alloc_lines(wp) == FAIL)
        {
            outofmem = TRUE;
#ifdef FEAT_WINDOWS
            goto give_up;
#endif
        }
    }
#ifdef FEAT_WINDOWS
give_up:
#endif

#ifdef FEAT_MBYTE
    for (i = 0; i < p_mco; ++i)
        if (new_ScreenLinesC[i] == NULL)
            break;
#endif
    if (new_ScreenLines == NULL
#ifdef FEAT_MBYTE
            || (enc_utf8 && (new_ScreenLinesUC == NULL || i != p_mco))
            || (enc_dbcs == DBCS_JPNU && new_ScreenLines2 == NULL)
#endif
            || new_ScreenAttrs == NULL
            || new_LineOffset == NULL
            || new_LineWraps == NULL
#ifdef FEAT_WINDOWS
            || new_TabPageIdxs == NULL
#endif
            || outofmem)
    {
        if (ScreenLines != NULL || !done_outofmem_msg)
        {
            /* guess the size */
            do_outofmem_msg((long_u)((Rows + 1) * Columns));

            /* Remember we did this to avoid getting outofmem messages over
             * and over again. */
            done_outofmem_msg = TRUE;
        }
        vim_free(new_ScreenLines);
        new_ScreenLines = NULL;
#ifdef FEAT_MBYTE
        vim_free(new_ScreenLinesUC);
        new_ScreenLinesUC = NULL;
        for (i = 0; i < p_mco; ++i)
        {
            vim_free(new_ScreenLinesC[i]);
            new_ScreenLinesC[i] = NULL;
        }
        vim_free(new_ScreenLines2);
        new_ScreenLines2 = NULL;
#endif
        vim_free(new_ScreenAttrs);
        new_ScreenAttrs = NULL;
        vim_free(new_LineOffset);
        new_LineOffset = NULL;
        vim_free(new_LineWraps);
        new_LineWraps = NULL;
#ifdef FEAT_WINDOWS
        vim_free(new_TabPageIdxs);
        new_TabPageIdxs = NULL;
#endif
    }
    else
    {
        done_outofmem_msg = FALSE;

        for (new_row = 0; new_row < Rows; ++new_row)
        {
            new_LineOffset[new_row] = new_row * Columns;
            new_LineWraps[new_row] = FALSE;

            /*
             * If the screen is not going to be cleared, copy as much as
             * possible from the old screen to the new one and clear the rest
             * (used when resizing the window at the "--more--" prompt or when
             * executing an external command, for the GUI).
             */
            if (!clear)
            {
                (void)vim_memset(new_ScreenLines + new_row * Columns,
                                      ' ', (size_t)Columns * sizeof(schar_T));
#ifdef FEAT_MBYTE
                if (enc_utf8)
                {
                    (void)vim_memset(new_ScreenLinesUC + new_row * Columns,
                                       0, (size_t)Columns * sizeof(u8char_T));
                    for (i = 0; i < p_mco; ++i)
                        (void)vim_memset(new_ScreenLinesC[i]
                                                          + new_row * Columns,
                                       0, (size_t)Columns * sizeof(u8char_T));
                }
                if (enc_dbcs == DBCS_JPNU)
                    (void)vim_memset(new_ScreenLines2 + new_row * Columns,
                                       0, (size_t)Columns * sizeof(schar_T));
#endif
                (void)vim_memset(new_ScreenAttrs + new_row * Columns,
                                        0, (size_t)Columns * sizeof(sattr_T));
                old_row = new_row + (screen_Rows - Rows);
                if (old_row >= 0 && ScreenLines != NULL)
                {
                    if (screen_Columns < Columns)
                        len = screen_Columns;
                    else
                        len = Columns;
#ifdef FEAT_MBYTE
                    /* When switching to utf-8 don't copy characters, they
                     * may be invalid now.  Also when p_mco changes. */
                    if (!(enc_utf8 && ScreenLinesUC == NULL)
                                                       && p_mco == Screen_mco)
#endif
                        mch_memmove(new_ScreenLines + new_LineOffset[new_row],
                                ScreenLines + LineOffset[old_row],
                                (size_t)len * sizeof(schar_T));
#ifdef FEAT_MBYTE
                    if (enc_utf8 && ScreenLinesUC != NULL
                                                       && p_mco == Screen_mco)
                    {
                        mch_memmove(new_ScreenLinesUC + new_LineOffset[new_row],
                                ScreenLinesUC + LineOffset[old_row],
                                (size_t)len * sizeof(u8char_T));
                        for (i = 0; i < p_mco; ++i)
                            mch_memmove(new_ScreenLinesC[i]
                                                    + new_LineOffset[new_row],
                                ScreenLinesC[i] + LineOffset[old_row],
                                (size_t)len * sizeof(u8char_T));
                    }
                    if (enc_dbcs == DBCS_JPNU && ScreenLines2 != NULL)
                        mch_memmove(new_ScreenLines2 + new_LineOffset[new_row],
                                ScreenLines2 + LineOffset[old_row],
                                (size_t)len * sizeof(schar_T));
#endif
                    mch_memmove(new_ScreenAttrs + new_LineOffset[new_row],
                            ScreenAttrs + LineOffset[old_row],
                            (size_t)len * sizeof(sattr_T));
                }
            }
        }
        /* Use the last line of the screen for the current line. */
        current_ScreenLine = new_ScreenLines + Rows * Columns;
    }

    free_screenlines();

    ScreenLines = new_ScreenLines;
#ifdef FEAT_MBYTE
    ScreenLinesUC = new_ScreenLinesUC;
    for (i = 0; i < p_mco; ++i)
        ScreenLinesC[i] = new_ScreenLinesC[i];
    Screen_mco = p_mco;
    ScreenLines2 = new_ScreenLines2;
#endif
    ScreenAttrs = new_ScreenAttrs;
    LineOffset = new_LineOffset;
    LineWraps = new_LineWraps;
#ifdef FEAT_WINDOWS
    TabPageIdxs = new_TabPageIdxs;
#endif

    /* It's important that screen_Rows and screen_Columns reflect the actual
     * size of ScreenLines[].  Set them before calling anything. */
#ifdef FEAT_GUI
    old_Rows = screen_Rows;
#endif
    screen_Rows = Rows;
    screen_Columns = Columns;

    must_redraw = CLEAR;        /* need to clear the screen later */
    if (clear)
        screenclear2();

#ifdef FEAT_GUI
    else if (gui.in_use
            && !gui.starting
            && ScreenLines != NULL
            && old_Rows != Rows)
    {
        (void)gui_redraw_block(0, 0, (int)Rows - 1, (int)Columns - 1, 0);
        /*
         * Adjust the position of the cursor, for when executing an external
         * command.
         */
        if (msg_row >= Rows)            /* Rows got smaller */
            msg_row = Rows - 1;         /* put cursor at last row */
        else if (Rows > old_Rows)       /* Rows got bigger */
            msg_row += Rows - old_Rows; /* put cursor in same place */
        if (msg_col >= Columns)         /* Columns got smaller */
            msg_col = Columns - 1;      /* put cursor at last column */
    }
#endif

    entered = FALSE;
    --RedrawingDisabled;

#ifdef FEAT_AUTOCMD
    /*
     * Do not apply autocommands more than 3 times to avoid an endless loop
     * in case applying autocommands always changes Rows or Columns.
     */
    if (starting == 0 && ++retry_count <= 3)
    {
        apply_autocmds(EVENT_VIMRESIZED, NULL, NULL, FALSE, curbuf);
        /* In rare cases, autocommands may have altered Rows or Columns,
         * jump back to check if we need to allocate the screen again. */
        goto retry;
    }
#endif
}

    void
free_screenlines()
{
#ifdef FEAT_MBYTE
    int         i;

    vim_free(ScreenLinesUC);
    for (i = 0; i < Screen_mco; ++i)
        vim_free(ScreenLinesC[i]);
    vim_free(ScreenLines2);
#endif
    vim_free(ScreenLines);
    vim_free(ScreenAttrs);
    vim_free(LineOffset);
    vim_free(LineWraps);
#ifdef FEAT_WINDOWS
    vim_free(TabPageIdxs);
#endif
}

    void
screenclear()
{
    check_for_delay(FALSE);
    screenalloc(FALSE);     /* allocate screen buffers if size changed */
    screenclear2();         /* clear the screen */
}

    static void
screenclear2()
{
    int     i;

    if (starting == NO_SCREEN || ScreenLines == NULL
#ifdef FEAT_GUI
            || (gui.in_use && gui.starting)
#endif
            )
        return;

#ifdef FEAT_GUI
    if (!gui.in_use)
#endif
        screen_attr = -1;       /* force setting the Normal colors */
    screen_stop_highlight();    /* don't want highlighting here */

#ifdef FEAT_CLIPBOARD
    /* disable selection without redrawing it */
    clip_scroll_selection(9999);
#endif

    /* blank out ScreenLines */
    for (i = 0; i < Rows; ++i)
    {
        lineclear(LineOffset[i], (int)Columns);
        LineWraps[i] = FALSE;
    }

    if (can_clear(T_CL))
    {
        out_str(T_CL);          /* clear the display */
        clear_cmdline = FALSE;
        mode_displayed = FALSE;
    }
    else
    {
        /* can't clear the screen, mark all chars with invalid attributes */
        for (i = 0; i < Rows; ++i)
            lineinvalid(LineOffset[i], (int)Columns);
        clear_cmdline = TRUE;
    }

    screen_cleared = TRUE;      /* can use contents of ScreenLines now */

    win_rest_invalid(firstwin);
    redraw_cmdline = TRUE;
#ifdef FEAT_WINDOWS
    redraw_tabline = TRUE;
#endif
    if (must_redraw == CLEAR)   /* no need to clear again */
        must_redraw = NOT_VALID;
    compute_cmdrow();
    msg_row = cmdline_row;      /* put cursor on last line for messages */
    msg_col = 0;
    screen_start();             /* don't know where cursor is now */
    msg_scrolled = 0;           /* can't scroll back */
    msg_didany = FALSE;
    msg_didout = FALSE;
}

/*
 * Clear one line in ScreenLines.
 */
    static void
lineclear(off, width)
    unsigned    off;
    int         width;
{
    (void)vim_memset(ScreenLines + off, ' ', (size_t)width * sizeof(schar_T));
#ifdef FEAT_MBYTE
    if (enc_utf8)
        (void)vim_memset(ScreenLinesUC + off, 0,
                                          (size_t)width * sizeof(u8char_T));
#endif
    (void)vim_memset(ScreenAttrs + off, 0, (size_t)width * sizeof(sattr_T));
}

/*
 * Mark one line in ScreenLines invalid by setting the attributes to an
 * invalid value.
 */
    static void
lineinvalid(off, width)
    unsigned    off;
    int         width;
{
    (void)vim_memset(ScreenAttrs + off, -1, (size_t)width * sizeof(sattr_T));
}

#ifdef FEAT_VERTSPLIT
/*
 * Copy part of a Screenline for vertically split window "wp".
 */
    static void
linecopy(to, from, wp)
    int         to;
    int         from;
    win_T       *wp;
{
    unsigned    off_to = LineOffset[to] + wp->w_wincol;
    unsigned    off_from = LineOffset[from] + wp->w_wincol;

    mch_memmove(ScreenLines + off_to, ScreenLines + off_from,
            wp->w_width * sizeof(schar_T));
# ifdef FEAT_MBYTE
    if (enc_utf8)
    {
        int     i;

        mch_memmove(ScreenLinesUC + off_to, ScreenLinesUC + off_from,
                wp->w_width * sizeof(u8char_T));
        for (i = 0; i < p_mco; ++i)
            mch_memmove(ScreenLinesC[i] + off_to, ScreenLinesC[i] + off_from,
                    wp->w_width * sizeof(u8char_T));
    }
    if (enc_dbcs == DBCS_JPNU)
        mch_memmove(ScreenLines2 + off_to, ScreenLines2 + off_from,
                wp->w_width * sizeof(schar_T));
# endif
    mch_memmove(ScreenAttrs + off_to, ScreenAttrs + off_from,
            wp->w_width * sizeof(sattr_T));
}
#endif

/*
 * Return TRUE if clearing with term string "p" would work.
 * It can't work when the string is empty or it won't set the right background.
 */
    int
can_clear(p)
    char_u      *p;
{
    return (*p != NUL && (t_colors <= 1
#ifdef FEAT_GUI
                || gui.in_use
#endif
                || cterm_normal_bg_color == 0 || *T_UT != NUL));
}

/*
 * Reset cursor position. Use whenever cursor was moved because of outputting
 * something directly to the screen (shell commands) or a terminal control
 * code.
 */
    void
screen_start()
{
    screen_cur_row = screen_cur_col = 9999;
}

/*
 * Move the cursor to position "row","col" in the screen.
 * This tries to find the most efficient way to move, minimizing the number of
 * characters sent to the terminal.
 */
    void
windgoto(row, col)
    int     row;
    int     col;
{
    sattr_T         *p;
    int             i;
    int             plan;
    int             cost;
    int             wouldbe_col;
    int             noinvcurs;
    char_u          *bs;
    int             goto_cost;
    int             attr;

#define GOTO_COST   7   /* assume a term_windgoto() takes about 7 chars */
#define HIGHL_COST  5   /* assume unhighlight takes 5 chars */

#define PLAN_LE     1
#define PLAN_CR     2
#define PLAN_NL     3
#define PLAN_WRITE  4
    /* Can't use ScreenLines unless initialized */
    if (ScreenLines == NULL)
        return;

    if (col != screen_cur_col || row != screen_cur_row)
    {
        /* Check for valid position. */
        if (row < 0)    /* window without text lines? */
            row = 0;
        if (row >= screen_Rows)
            row = screen_Rows - 1;
        if (col >= screen_Columns)
            col = screen_Columns - 1;

        /* check if no cursor movement is allowed in highlight mode */
        if (screen_attr && *T_MS == NUL)
            noinvcurs = HIGHL_COST;
        else
            noinvcurs = 0;
        goto_cost = GOTO_COST + noinvcurs;

        /*
         * Plan how to do the positioning:
         * 1. Use CR to move it to column 0, same row.
         * 2. Use T_LE to move it a few columns to the left.
         * 3. Use NL to move a few lines down, column 0.
         * 4. Move a few columns to the right with T_ND or by writing chars.
         *
         * Don't do this if the cursor went beyond the last column, the cursor
         * position is unknown then (some terminals wrap, some don't )
         *
         * First check if the highlighting attributes allow us to write
         * characters to move the cursor to the right.
         */
        if (row >= screen_cur_row && screen_cur_col < Columns)
        {
            /*
             * If the cursor is in the same row, bigger col, we can use CR
             * or T_LE.
             */
            bs = NULL;                      /* init for GCC */
            attr = screen_attr;
            if (row == screen_cur_row && col < screen_cur_col)
            {
                /* "le" is preferred over "bc", because "bc" is obsolete */
                if (*T_LE)
                    bs = T_LE;              /* "cursor left" */
                else
                    bs = T_BC;              /* "backspace character (old) */
                if (*bs)
                    cost = (screen_cur_col - col) * (int)STRLEN(bs);
                else
                    cost = 999;
                if (col + 1 < cost)         /* using CR is less characters */
                {
                    plan = PLAN_CR;
                    wouldbe_col = 0;
                    cost = 1;               /* CR is just one character */
                }
                else
                {
                    plan = PLAN_LE;
                    wouldbe_col = col;
                }
                if (noinvcurs)              /* will stop highlighting */
                {
                    cost += noinvcurs;
                    attr = 0;
                }
            }

            /*
             * If the cursor is above where we want to be, we can use CR LF.
             */
            else if (row > screen_cur_row)
            {
                plan = PLAN_NL;
                wouldbe_col = 0;
                cost = (row - screen_cur_row) * 2;  /* CR LF */
                if (noinvcurs)              /* will stop highlighting */
                {
                    cost += noinvcurs;
                    attr = 0;
                }
            }

            /*
             * If the cursor is in the same row, smaller col, just use write.
             */
            else
            {
                plan = PLAN_WRITE;
                wouldbe_col = screen_cur_col;
                cost = 0;
            }

            /*
             * Check if any characters that need to be written have the
             * correct attributes.  Also avoid UTF-8 characters.
             */
            i = col - wouldbe_col;
            if (i > 0)
                cost += i;
            if (cost < goto_cost && i > 0)
            {
                /*
                 * Check if the attributes are correct without additionally
                 * stopping highlighting.
                 */
                p = ScreenAttrs + LineOffset[row] + wouldbe_col;
                while (i && *p++ == attr)
                    --i;
                if (i != 0)
                {
                    /*
                     * Try if it works when highlighting is stopped here.
                     */
                    if (*--p == 0)
                    {
                        cost += noinvcurs;
                        while (i && *p++ == 0)
                            --i;
                    }
                    if (i != 0)
                        cost = 999;     /* different attributes, don't do it */
                }
#ifdef FEAT_MBYTE
                if (enc_utf8)
                {
                    /* Don't use an UTF-8 char for positioning, it's slow. */
                    for (i = wouldbe_col; i < col; ++i)
                        if (ScreenLinesUC[LineOffset[row] + i] != 0)
                        {
                            cost = 999;
                            break;
                        }
                }
#endif
            }

            /*
             * We can do it without term_windgoto()!
             */
            if (cost < goto_cost)
            {
                if (plan == PLAN_LE)
                {
                    if (noinvcurs)
                        screen_stop_highlight();
                    while (screen_cur_col > col)
                    {
                        out_str(bs);
                        --screen_cur_col;
                    }
                }
                else if (plan == PLAN_CR)
                {
                    if (noinvcurs)
                        screen_stop_highlight();
                    out_char('\r');
                    screen_cur_col = 0;
                }
                else if (plan == PLAN_NL)
                {
                    if (noinvcurs)
                        screen_stop_highlight();
                    while (screen_cur_row < row)
                    {
                        out_char('\n');
                        ++screen_cur_row;
                    }
                    screen_cur_col = 0;
                }

                i = col - screen_cur_col;
                if (i > 0)
                {
                    /*
                     * Use cursor-right if it's one character only.  Avoids
                     * removing a line of pixels from the last bold char, when
                     * using the bold trick in the GUI.
                     */
                    if (T_ND[0] != NUL && T_ND[1] == NUL)
                    {
                        while (i-- > 0)
                            out_char(*T_ND);
                    }
                    else
                    {
                        int     off;

                        off = LineOffset[row] + screen_cur_col;
                        while (i-- > 0)
                        {
                            if (ScreenAttrs[off] != screen_attr)
                                screen_stop_highlight();
#ifdef FEAT_MBYTE
                            out_flush_check();
#endif
                            out_char(ScreenLines[off]);
#ifdef FEAT_MBYTE
                            if (enc_dbcs == DBCS_JPNU
                                                  && ScreenLines[off] == 0x8e)
                                out_char(ScreenLines2[off]);
#endif
                            ++off;
                        }
                    }
                }
            }
        }
        else
            cost = 999;

        if (cost >= goto_cost)
        {
            if (noinvcurs)
                screen_stop_highlight();
            if (row == screen_cur_row && (col > screen_cur_col) &&
                                                                *T_CRI != NUL)
                term_cursor_right(col - screen_cur_col);
            else
                term_windgoto(row, col);
        }
        screen_cur_row = row;
        screen_cur_col = col;
    }
}

/*
 * Set cursor to its position in the current window.
 */
    void
setcursor()
{
    if (redrawing())
    {
        validate_cursor();
        windgoto(W_WINROW(curwin) + curwin->w_wrow,
                W_WINCOL(curwin) + (
#ifdef FEAT_RIGHTLEFT
                /* With 'rightleft' set and the cursor on a double-wide
                 * character, position it on the leftmost column. */
                curwin->w_p_rl ? ((int)W_WIDTH(curwin) - curwin->w_wcol - (
# ifdef FEAT_MBYTE
                        (has_mbyte
                           && (*mb_ptr2cells)(ml_get_cursor()) == 2
                           && vim_isprintc(gchar_cursor())) ? 2 :
# endif
                        1)) :
#endif
                                                            curwin->w_wcol));
    }
}


/*
 * insert 'line_count' lines at 'row' in window 'wp'
 * if 'invalid' is TRUE the wp->w_lines[].wl_lnum is invalidated.
 * if 'mayclear' is TRUE the screen will be cleared if it is faster than
 * scrolling.
 * Returns FAIL if the lines are not inserted, OK for success.
 */
    int
win_ins_lines(wp, row, line_count, invalid, mayclear)
    win_T       *wp;
    int         row;
    int         line_count;
    int         invalid;
    int         mayclear;
{
    int         did_delete;
    int         nextrow;
    int         lastrow;
    int         retval;

    if (invalid)
        wp->w_lines_valid = 0;

    if (wp->w_height < 5)
        return FAIL;

    if (line_count > wp->w_height - row)
        line_count = wp->w_height - row;

    retval = win_do_lines(wp, row, line_count, mayclear, FALSE);
    if (retval != MAYBE)
        return retval;

    /*
     * If there is a next window or a status line, we first try to delete the
     * lines at the bottom to avoid messing what is after the window.
     * If this fails and there are following windows, don't do anything to avoid
     * messing up those windows, better just redraw.
     */
    did_delete = FALSE;
#ifdef FEAT_WINDOWS
    if (wp->w_next != NULL || wp->w_status_height)
    {
        if (screen_del_lines(0, W_WINROW(wp) + wp->w_height - line_count,
                                    line_count, (int)Rows, FALSE, NULL) == OK)
            did_delete = TRUE;
        else if (wp->w_next)
            return FAIL;
    }
#endif
    /*
     * if no lines deleted, blank the lines that will end up below the window
     */
    if (!did_delete)
    {
#ifdef FEAT_WINDOWS
        wp->w_redr_status = TRUE;
#endif
        redraw_cmdline = TRUE;
        nextrow = W_WINROW(wp) + wp->w_height + W_STATUS_HEIGHT(wp);
        lastrow = nextrow + line_count;
        if (lastrow > Rows)
            lastrow = Rows;
        screen_fill(nextrow - line_count, lastrow - line_count,
                  W_WINCOL(wp), (int)W_ENDCOL(wp),
                  ' ', ' ', 0);
    }

    if (screen_ins_lines(0, W_WINROW(wp) + row, line_count, (int)Rows, NULL)
                                                                      == FAIL)
    {
            /* deletion will have messed up other windows */
        if (did_delete)
        {
#ifdef FEAT_WINDOWS
            wp->w_redr_status = TRUE;
#endif
            win_rest_invalid(W_NEXT(wp));
        }
        return FAIL;
    }

    return OK;
}

/*
 * delete "line_count" window lines at "row" in window "wp"
 * If "invalid" is TRUE curwin->w_lines[] is invalidated.
 * If "mayclear" is TRUE the screen will be cleared if it is faster than
 * scrolling
 * Return OK for success, FAIL if the lines are not deleted.
 */
    int
win_del_lines(wp, row, line_count, invalid, mayclear)
    win_T       *wp;
    int         row;
    int         line_count;
    int         invalid;
    int         mayclear;
{
    int         retval;

    if (invalid)
        wp->w_lines_valid = 0;

    if (line_count > wp->w_height - row)
        line_count = wp->w_height - row;

    retval = win_do_lines(wp, row, line_count, mayclear, TRUE);
    if (retval != MAYBE)
        return retval;

    if (screen_del_lines(0, W_WINROW(wp) + row, line_count,
                                              (int)Rows, FALSE, NULL) == FAIL)
        return FAIL;

#ifdef FEAT_WINDOWS
    /*
     * If there are windows or status lines below, try to put them at the
     * correct place. If we can't do that, they have to be redrawn.
     */
    if (wp->w_next || wp->w_status_height || cmdline_row < Rows - 1)
    {
        if (screen_ins_lines(0, W_WINROW(wp) + wp->w_height - line_count,
                                         line_count, (int)Rows, NULL) == FAIL)
        {
            wp->w_redr_status = TRUE;
            win_rest_invalid(wp->w_next);
        }
    }
    /*
     * If this is the last window and there is no status line, redraw the
     * command line later.
     */
    else
#endif
        redraw_cmdline = TRUE;
    return OK;
}

/*
 * Common code for win_ins_lines() and win_del_lines().
 * Returns OK or FAIL when the work has been done.
 * Returns MAYBE when not finished yet.
 */
    static int
win_do_lines(wp, row, line_count, mayclear, del)
    win_T       *wp;
    int         row;
    int         line_count;
    int         mayclear;
    int         del;
{
    int         retval;

    if (!redrawing() || line_count <= 0)
        return FAIL;

    /* only a few lines left: redraw is faster */
    if (mayclear && Rows - line_count < 5
#ifdef FEAT_VERTSPLIT
            && wp->w_width == Columns
#endif
            )
    {
        screenclear();      /* will set wp->w_lines_valid to 0 */
        return FAIL;
    }

    /*
     * Delete all remaining lines
     */
    if (row + line_count >= wp->w_height)
    {
        screen_fill(W_WINROW(wp) + row, W_WINROW(wp) + wp->w_height,
                W_WINCOL(wp), (int)W_ENDCOL(wp),
                ' ', ' ', 0);
        return OK;
    }

    /*
     * when scrolling, the message on the command line should be cleared,
     * otherwise it will stay there forever.
     */
    clear_cmdline = TRUE;

    /*
     * If the terminal can set a scroll region, use that.
     * Always do this in a vertically split window.  This will redraw from
     * ScreenLines[] when t_CV isn't defined.  That's faster than using
     * win_line().
     * Don't use a scroll region when we are going to redraw the text, writing
     * a character in the lower right corner of the scroll region causes a
     * scroll-up in the DJGPP version.
     */
    if (scroll_region
#ifdef FEAT_VERTSPLIT
            || W_WIDTH(wp) != Columns
#endif
            )
    {
#ifdef FEAT_VERTSPLIT
        if (scroll_region && (wp->w_width == Columns || *T_CSV != NUL))
#endif
            scroll_region_set(wp, row);
        if (del)
            retval = screen_del_lines(W_WINROW(wp) + row, 0, line_count,
                                               wp->w_height - row, FALSE, wp);
        else
            retval = screen_ins_lines(W_WINROW(wp) + row, 0, line_count,
                                                      wp->w_height - row, wp);
#ifdef FEAT_VERTSPLIT
        if (scroll_region && (wp->w_width == Columns || *T_CSV != NUL))
#endif
            scroll_region_reset();
        return retval;
    }

#ifdef FEAT_WINDOWS
    if (wp->w_next != NULL && p_tf) /* don't delete/insert on fast terminal */
        return FAIL;
#endif

    return MAYBE;
}

/*
 * window 'wp' and everything after it is messed up, mark it for redraw
 */
    static void
win_rest_invalid(wp)
    win_T       *wp;
{
#ifdef FEAT_WINDOWS
    while (wp != NULL)
#else
    if (wp != NULL)
#endif
    {
        redraw_win_later(wp, NOT_VALID);
#ifdef FEAT_WINDOWS
        wp->w_redr_status = TRUE;
        wp = wp->w_next;
#endif
    }
    redraw_cmdline = TRUE;
}

/*
 * The rest of the routines in this file perform screen manipulations. The
 * given operation is performed physically on the screen. The corresponding
 * change is also made to the internal screen image. In this way, the editor
 * anticipates the effect of editing changes on the appearance of the screen.
 * That way, when we call screenupdate a complete redraw isn't usually
 * necessary. Another advantage is that we can keep adding code to anticipate
 * screen changes, and in the meantime, everything still works.
 */

/*
 * types for inserting or deleting lines
 */
#define USE_T_CAL   1
#define USE_T_CDL   2
#define USE_T_AL    3
#define USE_T_CE    4
#define USE_T_DL    5
#define USE_T_SR    6
#define USE_NL      7
#define USE_T_CD    8
#define USE_REDRAW  9

/*
 * insert lines on the screen and update ScreenLines[]
 * 'end' is the line after the scrolled part. Normally it is Rows.
 * When scrolling region used 'off' is the offset from the top for the region.
 * 'row' and 'end' are relative to the start of the region.
 *
 * return FAIL for failure, OK for success.
 */
    int
screen_ins_lines(off, row, line_count, end, wp)
    int         off;
    int         row;
    int         line_count;
    int         end;
    win_T       *wp;        /* NULL or window to use width from */
{
    int         i;
    int         j;
    unsigned    temp;
    int         cursor_row;
    int         type;
    int         result_empty;
    int         can_ce = can_clear(T_CE);

    /*
     * FAIL if
     * - there is no valid screen
     * - the screen has to be redrawn completely
     * - the line count is less than one
     * - the line count is more than 'ttyscroll'
     */
    if (!screen_valid(TRUE) || line_count <= 0 || line_count > p_ttyscroll)
        return FAIL;

    /*
     * There are seven ways to insert lines:
     * 0. When in a vertically split window and t_CV isn't set, redraw the
     *    characters from ScreenLines[].
     * 1. Use T_CD (clear to end of display) if it exists and the result of
     *    the insert is just empty lines
     * 2. Use T_CAL (insert multiple lines) if it exists and T_AL is not
     *    present or line_count > 1. It looks better if we do all the inserts
     *    at once.
     * 3. Use T_CDL (delete multiple lines) if it exists and the result of the
     *    insert is just empty lines and T_CE is not present or line_count >
     *    1.
     * 4. Use T_AL (insert line) if it exists.
     * 5. Use T_CE (erase line) if it exists and the result of the insert is
     *    just empty lines.
     * 6. Use T_DL (delete line) if it exists and the result of the insert is
     *    just empty lines.
     * 7. Use T_SR (scroll reverse) if it exists and inserting at row 0 and
     *    the 'da' flag is not set or we have clear line capability.
     * 8. redraw the characters from ScreenLines[].
     *
     * Careful: In a hpterm scroll reverse doesn't work as expected, it moves
     * the scrollbar for the window. It does have insert line, use that if it
     * exists.
     */
    result_empty = (row + line_count >= end);
#ifdef FEAT_VERTSPLIT
    if (wp != NULL && wp->w_width != Columns && *T_CSV == NUL)
        type = USE_REDRAW;
    else
#endif
    if (can_clear(T_CD) && result_empty)
        type = USE_T_CD;
    else if (*T_CAL != NUL && (line_count > 1 || *T_AL == NUL))
        type = USE_T_CAL;
    else if (*T_CDL != NUL && result_empty && (line_count > 1 || !can_ce))
        type = USE_T_CDL;
    else if (*T_AL != NUL)
        type = USE_T_AL;
    else if (can_ce && result_empty)
        type = USE_T_CE;
    else if (*T_DL != NUL && result_empty)
        type = USE_T_DL;
    else if (*T_SR != NUL && row == 0 && (*T_DA == NUL || can_ce))
        type = USE_T_SR;
    else
        return FAIL;

    /*
     * For clearing the lines screen_del_lines() is used. This will also take
     * care of t_db if necessary.
     */
    if (type == USE_T_CD || type == USE_T_CDL ||
                                         type == USE_T_CE || type == USE_T_DL)
        return screen_del_lines(off, row, line_count, end, FALSE, wp);

    /*
     * If text is retained below the screen, first clear or delete as many
     * lines at the bottom of the window as are about to be inserted so that
     * the deleted lines won't later surface during a screen_del_lines.
     */
    if (*T_DB)
        screen_del_lines(off, end - line_count, line_count, end, FALSE, wp);

#ifdef FEAT_CLIPBOARD
    /* Remove a modeless selection when inserting lines halfway the screen
     * or not the full width of the screen. */
    if (off + row > 0
# ifdef FEAT_VERTSPLIT
            || (wp != NULL && wp->w_width != Columns)
# endif
       )
        clip_clear_selection();
    else
        clip_scroll_selection(-line_count);
#endif

#ifdef FEAT_GUI
    /* Don't update the GUI cursor here, ScreenLines[] is invalid until the
     * scrolling is actually carried out. */
    gui_dont_update_cursor();
#endif

    if (*T_CCS != NUL)     /* cursor relative to region */
        cursor_row = row;
    else
        cursor_row = row + off;

    /*
     * Shift LineOffset[] line_count down to reflect the inserted lines.
     * Clear the inserted lines in ScreenLines[].
     */
    row += off;
    end += off;
    for (i = 0; i < line_count; ++i)
    {
#ifdef FEAT_VERTSPLIT
        if (wp != NULL && wp->w_width != Columns)
        {
            /* need to copy part of a line */
            j = end - 1 - i;
            while ((j -= line_count) >= row)
                linecopy(j + line_count, j, wp);
            j += line_count;
            if (can_clear((char_u *)" "))
                lineclear(LineOffset[j] + wp->w_wincol, wp->w_width);
            else
                lineinvalid(LineOffset[j] + wp->w_wincol, wp->w_width);
            LineWraps[j] = FALSE;
        }
        else
#endif
        {
            j = end - 1 - i;
            temp = LineOffset[j];
            while ((j -= line_count) >= row)
            {
                LineOffset[j + line_count] = LineOffset[j];
                LineWraps[j + line_count] = LineWraps[j];
            }
            LineOffset[j + line_count] = temp;
            LineWraps[j + line_count] = FALSE;
            if (can_clear((char_u *)" "))
                lineclear(temp, (int)Columns);
            else
                lineinvalid(temp, (int)Columns);
        }
    }

    screen_stop_highlight();
    windgoto(cursor_row, 0);

#ifdef FEAT_VERTSPLIT
    /* redraw the characters */
    if (type == USE_REDRAW)
        redraw_block(row, end, wp);
    else
#endif
        if (type == USE_T_CAL)
    {
        term_append_lines(line_count);
        screen_start();         /* don't know where cursor is now */
    }
    else
    {
        for (i = 0; i < line_count; i++)
        {
            if (type == USE_T_AL)
            {
                if (i && cursor_row != 0)
                    windgoto(cursor_row, 0);
                out_str(T_AL);
            }
            else  /* type == USE_T_SR */
                out_str(T_SR);
            screen_start();         /* don't know where cursor is now */
        }
    }

    /*
     * With scroll-reverse and 'da' flag set we need to clear the lines that
     * have been scrolled down into the region.
     */
    if (type == USE_T_SR && *T_DA)
    {
        for (i = 0; i < line_count; ++i)
        {
            windgoto(off + i, 0);
            out_str(T_CE);
            screen_start();         /* don't know where cursor is now */
        }
    }

#ifdef FEAT_GUI
    gui_can_update_cursor();
    if (gui.in_use)
        out_flush();    /* always flush after a scroll */
#endif
    return OK;
}

/*
 * delete lines on the screen and update ScreenLines[]
 * 'end' is the line after the scrolled part. Normally it is Rows.
 * When scrolling region used 'off' is the offset from the top for the region.
 * 'row' and 'end' are relative to the start of the region.
 *
 * Return OK for success, FAIL if the lines are not deleted.
 */
/*ARGSUSED*/
    int
screen_del_lines(off, row, line_count, end, force, wp)
    int         off;
    int         row;
    int         line_count;
    int         end;
    int         force;          /* even when line_count > p_ttyscroll */
    win_T       *wp;            /* NULL or window to use width from */
{
    int         j;
    int         i;
    unsigned    temp;
    int         cursor_row;
    int         cursor_end;
    int         result_empty;   /* result is empty until end of region */
    int         can_delete;     /* deleting line codes can be used */
    int         type;

    /*
     * FAIL if
     * - there is no valid screen
     * - the screen has to be redrawn completely
     * - the line count is less than one
     * - the line count is more than 'ttyscroll'
     */
    if (!screen_valid(TRUE) || line_count <= 0 ||
                                         (!force && line_count > p_ttyscroll))
        return FAIL;

    /*
     * Check if the rest of the current region will become empty.
     */
    result_empty = row + line_count >= end;

    /*
     * We can delete lines only when 'db' flag not set or when 'ce' option
     * available.
     */
    can_delete = (*T_DB == NUL || can_clear(T_CE));

    /*
     * There are six ways to delete lines:
     * 0. When in a vertically split window and t_CV isn't set, redraw the
     *    characters from ScreenLines[].
     * 1. Use T_CD if it exists and the result is empty.
     * 2. Use newlines if row == 0 and count == 1 or T_CDL does not exist.
     * 3. Use T_CDL (delete multiple lines) if it exists and line_count > 1 or
     *    none of the other ways work.
     * 4. Use T_CE (erase line) if the result is empty.
     * 5. Use T_DL (delete line) if it exists.
     * 6. redraw the characters from ScreenLines[].
     */
#ifdef FEAT_VERTSPLIT
    if (wp != NULL && wp->w_width != Columns && *T_CSV == NUL)
        type = USE_REDRAW;
    else
#endif
    if (can_clear(T_CD) && result_empty)
        type = USE_T_CD;
#if defined(__BEOS__) && defined(BEOS_DR8)
    /*
     * USE_NL does not seem to work in Terminal of DR8 so we set T_DB="" in
     * its internal termcap... this works okay for tests which test *T_DB !=
     * NUL.  It has the disadvantage that the user cannot use any :set t_*
     * command to get T_DB (back) to empty_option, only :set term=... will do
     * the trick...
     * Anyway, this hack will hopefully go away with the next OS release.
     * (Olaf Seibert)
     */
    else if (row == 0 && T_DB == empty_option
                                        && (line_count == 1 || *T_CDL == NUL))
#else
    else if (row == 0 && (
#ifndef AMIGA
        /* On the Amiga, somehow '\n' on the last line doesn't always scroll
         * up, so use delete-line command */
                            line_count == 1 ||
#endif
                                                *T_CDL == NUL))
#endif
        type = USE_NL;
    else if (*T_CDL != NUL && line_count > 1 && can_delete)
        type = USE_T_CDL;
    else if (can_clear(T_CE) && result_empty
#ifdef FEAT_VERTSPLIT
            && (wp == NULL || wp->w_width == Columns)
#endif
            )
        type = USE_T_CE;
    else if (*T_DL != NUL && can_delete)
        type = USE_T_DL;
    else if (*T_CDL != NUL && can_delete)
        type = USE_T_CDL;
    else
        return FAIL;

#ifdef FEAT_CLIPBOARD
    /* Remove a modeless selection when deleting lines halfway the screen or
     * not the full width of the screen. */
    if (off + row > 0
# ifdef FEAT_VERTSPLIT
            || (wp != NULL && wp->w_width != Columns)
# endif
       )
        clip_clear_selection();
    else
        clip_scroll_selection(line_count);
#endif

#ifdef FEAT_GUI
    /* Don't update the GUI cursor here, ScreenLines[] is invalid until the
     * scrolling is actually carried out. */
    gui_dont_update_cursor();
#endif

    if (*T_CCS != NUL)      /* cursor relative to region */
    {
        cursor_row = row;
        cursor_end = end;
    }
    else
    {
        cursor_row = row + off;
        cursor_end = end + off;
    }

    /*
     * Now shift LineOffset[] line_count up to reflect the deleted lines.
     * Clear the inserted lines in ScreenLines[].
     */
    row += off;
    end += off;
    for (i = 0; i < line_count; ++i)
    {
#ifdef FEAT_VERTSPLIT
        if (wp != NULL && wp->w_width != Columns)
        {
            /* need to copy part of a line */
            j = row + i;
            while ((j += line_count) <= end - 1)
                linecopy(j - line_count, j, wp);
            j -= line_count;
            if (can_clear((char_u *)" "))
                lineclear(LineOffset[j] + wp->w_wincol, wp->w_width);
            else
                lineinvalid(LineOffset[j] + wp->w_wincol, wp->w_width);
            LineWraps[j] = FALSE;
        }
        else
#endif
        {
            /* whole width, moving the line pointers is faster */
            j = row + i;
            temp = LineOffset[j];
            while ((j += line_count) <= end - 1)
            {
                LineOffset[j - line_count] = LineOffset[j];
                LineWraps[j - line_count] = LineWraps[j];
            }
            LineOffset[j - line_count] = temp;
            LineWraps[j - line_count] = FALSE;
            if (can_clear((char_u *)" "))
                lineclear(temp, (int)Columns);
            else
                lineinvalid(temp, (int)Columns);
        }
    }

    screen_stop_highlight();

#ifdef FEAT_VERTSPLIT
    /* redraw the characters */
    if (type == USE_REDRAW)
        redraw_block(row, end, wp);
    else
#endif
        if (type == USE_T_CD)   /* delete the lines */
    {
        windgoto(cursor_row, 0);
        out_str(T_CD);
        screen_start();                 /* don't know where cursor is now */
    }
    else if (type == USE_T_CDL)
    {
        windgoto(cursor_row, 0);
        term_delete_lines(line_count);
        screen_start();                 /* don't know where cursor is now */
    }
    /*
     * Deleting lines at top of the screen or scroll region: Just scroll
     * the whole screen (scroll region) up by outputting newlines on the
     * last line.
     */
    else if (type == USE_NL)
    {
        windgoto(cursor_end - 1, 0);
        for (i = line_count; --i >= 0; )
            out_char('\n');             /* cursor will remain on same line */
    }
    else
    {
        for (i = line_count; --i >= 0; )
        {
            if (type == USE_T_DL)
            {
                windgoto(cursor_row, 0);
                out_str(T_DL);          /* delete a line */
            }
            else /* type == USE_T_CE */
            {
                windgoto(cursor_row + i, 0);
                out_str(T_CE);          /* erase a line */
            }
            screen_start();             /* don't know where cursor is now */
        }
    }

    /*
     * If the 'db' flag is set, we need to clear the lines that have been
     * scrolled up at the bottom of the region.
     */
    if (*T_DB && (type == USE_T_DL || type == USE_T_CDL))
    {
        for (i = line_count; i > 0; --i)
        {
            windgoto(cursor_end - i, 0);
            out_str(T_CE);              /* erase a line */
            screen_start();             /* don't know where cursor is now */
        }
    }

#ifdef FEAT_GUI
    gui_can_update_cursor();
    if (gui.in_use)
        out_flush();    /* always flush after a scroll */
#endif

    return OK;
}

/*
 * show the current mode and ruler
 *
 * If clear_cmdline is TRUE, clear the rest of the cmdline.
 * If clear_cmdline is FALSE there may be a message there that needs to be
 * cleared only if a mode is shown.
 * Return the length of the message (0 if no message).
 */
    int
showmode()
{
    int         need_clear;
    int         length = 0;
    int         do_mode;
    int         attr;
    int         nwr_save;
#ifdef FEAT_INS_EXPAND
    int         sub_attr;
#endif

    do_mode = ((p_smd && msg_silent == 0)
            && ((State & INSERT)
                || restart_edit
#ifdef FEAT_VISUAL
                || VIsual_active
#endif
                ));
    if (do_mode || Recording)
    {
        /*
         * Don't show mode right now, when not redrawing or inside a mapping.
         * Call char_avail() only when we are going to show something, because
         * it takes a bit of time.
         */
        if (!redrawing() || (char_avail() && !KeyTyped) || msg_silent != 0)
        {
            redraw_cmdline = TRUE;              /* show mode later */
            return 0;
        }

        nwr_save = need_wait_return;

        /* wait a bit before overwriting an important message */
        check_for_delay(FALSE);

        /* if the cmdline is more than one line high, erase top lines */
        need_clear = clear_cmdline;
        if (clear_cmdline && cmdline_row < Rows - 1)
            msg_clr_cmdline();                  /* will reset clear_cmdline */

        /* Position on the last line in the window, column 0 */
        msg_pos_mode();
        cursor_off();
        attr = hl_attr(HLF_CM);                 /* Highlight mode */
        if (do_mode)
        {
            MSG_PUTS_ATTR("--", attr);
#if defined(FEAT_XIM)
# if 0  /* old version, changed by SungHyun Nam July 2008 */
            if (xic != NULL && im_get_status() && !p_imdisable
                                        && curbuf->b_p_iminsert == B_IMODE_IM)
# else
            if (
#  ifdef HAVE_GTK2
                    preedit_get_status()
#  else
                    im_get_status()
#  endif
               )
# endif
# ifdef HAVE_GTK2 /* most of the time, it's not XIM being used */
                MSG_PUTS_ATTR(" IM", attr);
# else
                MSG_PUTS_ATTR(" XIM", attr);
# endif
#endif
#if defined(FEAT_HANGULIN) && defined(FEAT_GUI)
            if (gui.in_use)
            {
                if (hangul_input_state_get())
                    MSG_PUTS_ATTR(" \307\321\261\333", attr);   /* HANGUL */
            }
#endif
#ifdef FEAT_INS_EXPAND
            if (edit_submode != NULL)           /* CTRL-X in Insert mode */
            {
                /* These messages can get long, avoid a wrap in a narrow
                 * window.  Prefer showing edit_submode_extra. */
                length = (Rows - msg_row) * Columns - 3;
                if (edit_submode_extra != NULL)
                    length -= vim_strsize(edit_submode_extra);
                if (length > 0)
                {
                    if (edit_submode_pre != NULL)
                        length -= vim_strsize(edit_submode_pre);
                    if (length - vim_strsize(edit_submode) > 0)
                    {
                        if (edit_submode_pre != NULL)
                            msg_puts_attr(edit_submode_pre, attr);
                        msg_puts_attr(edit_submode, attr);
                    }
                    if (edit_submode_extra != NULL)
                    {
                        MSG_PUTS_ATTR(" ", attr);  /* add a space in between */
                        if ((int)edit_submode_highl < (int)HLF_COUNT)
                            sub_attr = hl_attr(edit_submode_highl);
                        else
                            sub_attr = attr;
                        msg_puts_attr(edit_submode_extra, sub_attr);
                    }
                }
                length = 0;
            }
            else
#endif
            {
#ifdef FEAT_VREPLACE
                if (State & VREPLACE_FLAG)
                    MSG_PUTS_ATTR(_(" VREPLACE"), attr);
                else
#endif
                    if (State & REPLACE_FLAG)
                    MSG_PUTS_ATTR(_(" REPLACE"), attr);
                else if (State & INSERT)
                {
#ifdef FEAT_RIGHTLEFT
                    if (p_ri)
                        MSG_PUTS_ATTR(_(" REVERSE"), attr);
#endif
                    MSG_PUTS_ATTR(_(" INSERT"), attr);
                }
                else if (restart_edit == 'I')
                    MSG_PUTS_ATTR(_(" (insert)"), attr);
                else if (restart_edit == 'R')
                    MSG_PUTS_ATTR(_(" (replace)"), attr);
                else if (restart_edit == 'V')
                    MSG_PUTS_ATTR(_(" (vreplace)"), attr);
#ifdef FEAT_RIGHTLEFT
                if (p_hkmap)
                    MSG_PUTS_ATTR(_(" Hebrew"), attr);
# ifdef FEAT_FKMAP
                if (p_fkmap)
                    MSG_PUTS_ATTR(farsi_text_5, attr);
# endif
#endif
#ifdef FEAT_KEYMAP
                if (State & LANGMAP)
                {
# ifdef FEAT_ARABIC
                    if (curwin->w_p_arab)
                        MSG_PUTS_ATTR(_(" Arabic"), attr);
                    else
# endif
                        MSG_PUTS_ATTR(_(" (lang)"), attr);
                }
#endif
                if ((State & INSERT) && p_paste)
                    MSG_PUTS_ATTR(_(" (paste)"), attr);

#ifdef FEAT_VISUAL
                if (VIsual_active)
                {
                    char *p;

                    /* Don't concatenate separate words to avoid translation
                     * problems. */
                    switch ((VIsual_select ? 4 : 0)
                            + (VIsual_mode == Ctrl_V) * 2
                            + (VIsual_mode == 'V'))
                    {
                        case 0: p = N_(" VISUAL"); break;
                        case 1: p = N_(" VISUAL LINE"); break;
                        case 2: p = N_(" VISUAL BLOCK"); break;
                        case 4: p = N_(" SELECT"); break;
                        case 5: p = N_(" SELECT LINE"); break;
                        default: p = N_(" SELECT BLOCK"); break;
                    }
                    MSG_PUTS_ATTR(_(p), attr);
                }
#endif
                MSG_PUTS_ATTR(" --", attr);
            }

            need_clear = TRUE;
        }
        if (Recording
#ifdef FEAT_INS_EXPAND
                && edit_submode == NULL     /* otherwise it gets too long */
#endif
                )
        {
            MSG_PUTS_ATTR(_("recording"), attr);
            need_clear = TRUE;
        }

        mode_displayed = TRUE;
        if (need_clear || clear_cmdline)
            msg_clr_eos();
        msg_didout = FALSE;             /* overwrite this message */
        length = msg_col;
        msg_col = 0;
        need_wait_return = nwr_save;    /* never ask for hit-return for this */
    }
    else if (clear_cmdline && msg_silent == 0)
        /* Clear the whole command line.  Will reset "clear_cmdline". */
        msg_clr_cmdline();

#ifdef FEAT_CMDL_INFO
# ifdef FEAT_VISUAL
    /* In Visual mode the size of the selected area must be redrawn. */
    if (VIsual_active)
        clear_showcmd();
# endif

    /* If the last window has no status line, the ruler is after the mode
     * message and must be redrawn */
    if (redrawing()
# ifdef FEAT_WINDOWS
            && lastwin->w_status_height == 0
# endif
       )
        win_redr_ruler(lastwin, TRUE);
#endif
    redraw_cmdline = FALSE;
    clear_cmdline = FALSE;

    return length;
}

/*
 * Position for a mode message.
 */
    static void
msg_pos_mode()
{
    msg_col = 0;
    msg_row = Rows - 1;
}

/*
 * Delete mode message.  Used when ESC is typed which is expected to end
 * Insert mode (but Insert mode didn't end yet!).
 * Caller should check "mode_displayed".
 */
    void
unshowmode(force)
    int     force;
{
    /*
     * Don't delete it right now, when not redrawing or insided a mapping.
     */
    if (!redrawing() || (!force && char_avail() && !KeyTyped))
        redraw_cmdline = TRUE;          /* delete mode later */
    else
    {
        msg_pos_mode();
        if (Recording)
            MSG_PUTS_ATTR(_("recording"), hl_attr(HLF_CM));
        msg_clr_eos();
    }
}

#if defined(FEAT_WINDOWS)
/*
 * Draw the tab pages line at the top of the Vim window.
 */
    static void
draw_tabline()
{
    int         tabcount = 0;
    tabpage_T   *tp;
    int         tabwidth;
    int         col = 0;
    int         scol = 0;
    int         attr;
    win_T       *wp;
    win_T       *cwp;
    int         wincount;
    int         modified;
    int         c;
    int         len;
    int         attr_sel = hl_attr(HLF_TPS);
    int         attr_nosel = hl_attr(HLF_TP);
    int         attr_fill = hl_attr(HLF_TPF);
    char_u      *p;
    int         room;
    int         use_sep_chars = (t_colors < 8
#ifdef FEAT_GUI
                                            && !gui.in_use
#endif
                                            );

    redraw_tabline = FALSE;

#ifdef FEAT_GUI_TABLINE
    /* Take care of a GUI tabline. */
    if (gui_use_tabline())
    {
        gui_update_tabline();
        return;
    }
#endif

    if (tabline_height() < 1)
        return;

#if defined(FEAT_STL_OPT)

    /* Init TabPageIdxs[] to zero: Clicking outside of tabs has no effect. */
    for (scol = 0; scol < Columns; ++scol)
        TabPageIdxs[scol] = 0;

    /* Use the 'tabline' option if it's set. */
    if (*p_tal != NUL)
    {
        int     save_called_emsg = called_emsg;

        /* Check for an error.  If there is one we would loop in redrawing the
         * screen.  Avoid that by making 'tabline' empty. */
        called_emsg = FALSE;
        win_redr_custom(NULL, FALSE);
        if (called_emsg)
            set_string_option_direct((char_u *)"tabline", -1,
                                           (char_u *)"", OPT_FREE, SID_ERROR);
        called_emsg |= save_called_emsg;
    }
    else
#endif
    {
        for (tp = first_tabpage; tp != NULL; tp = tp->tp_next)
            ++tabcount;

        tabwidth = (Columns - 1 + tabcount / 2) / tabcount;
        if (tabwidth < 6)
            tabwidth = 6;

        attr = attr_nosel;
        tabcount = 0;
        scol = 0;
        for (tp = first_tabpage; tp != NULL && col < Columns - 4;
                                                             tp = tp->tp_next)
        {
            scol = col;

            if (tp->tp_topframe == topframe)
                attr = attr_sel;
            if (use_sep_chars && col > 0)
                screen_putchar('|', 0, col++, attr);

            if (tp->tp_topframe != topframe)
                attr = attr_nosel;

            screen_putchar(' ', 0, col++, attr);

            if (tp == curtab)
            {
                cwp = curwin;
                wp = firstwin;
            }
            else
            {
                cwp = tp->tp_curwin;
                wp = tp->tp_firstwin;
            }

            modified = FALSE;
            for (wincount = 0; wp != NULL; wp = wp->w_next, ++wincount)
                if (bufIsChanged(wp->w_buffer))
                    modified = TRUE;
            if (modified || wincount > 1)
            {
                if (wincount > 1)
                {
                    vim_snprintf((char *)NameBuff, MAXPATHL, "%d", wincount);
                    len = (int)STRLEN(NameBuff);
                    if (col + len >= Columns - 3)
                        break;
                    screen_puts_len(NameBuff, len, 0, col,
#if defined(FEAT_SYN_HL)
                                           hl_combine_attr(attr, hl_attr(HLF_T))
#else
                                           attr
#endif
                                               );
                    col += len;
                }
                if (modified)
                    screen_puts_len((char_u *)"+", 1, 0, col++, attr);
                screen_putchar(' ', 0, col++, attr);
            }

            room = scol - col + tabwidth - 1;
            if (room > 0)
            {
                /* Get buffer name in NameBuff[] */
                get_trans_bufname(cwp->w_buffer);
                shorten_dir(NameBuff);
                len = vim_strsize(NameBuff);
                p = NameBuff;
#ifdef FEAT_MBYTE
                if (has_mbyte)
                    while (len > room)
                    {
                        len -= ptr2cells(p);
                        mb_ptr_adv(p);
                    }
                else
#endif
                    if (len > room)
                {
                    p += len - room;
                    len = room;
                }
                if (len > Columns - col - 1)
                    len = Columns - col - 1;

                screen_puts_len(p, (int)STRLEN(p), 0, col, attr);
                col += len;
            }
            screen_putchar(' ', 0, col++, attr);

            /* Store the tab page number in TabPageIdxs[], so that
             * jump_to_mouse() knows where each one is. */
            ++tabcount;
            while (scol < col)
                TabPageIdxs[scol++] = tabcount;
        }

        if (use_sep_chars)
            c = '_';
        else
            c = ' ';
        screen_fill(0, 1, col, (int)Columns, c, c, attr_fill);

        /* Put an "X" for closing the current tab if there are several. */
        if (first_tabpage->tp_next != NULL)
        {
            screen_putchar('X', 0, (int)Columns - 1, attr_nosel);
            TabPageIdxs[Columns - 1] = -999;
        }
    }

    /* Reset the flag here again, in case evaluating 'tabline' causes it to be
     * set. */
    redraw_tabline = FALSE;
}

/*
 * Get buffer name for "buf" into NameBuff[].
 * Takes care of special buffer names and translates special characters.
 */
    void
get_trans_bufname(buf)
    buf_T       *buf;
{
    if (buf_spname(buf) != NULL)
        STRCPY(NameBuff, buf_spname(buf));
    else
        home_replace(buf, buf->b_fname, NameBuff, MAXPATHL, TRUE);
    trans_characters(NameBuff, MAXPATHL);
}
#endif

#if defined(FEAT_WINDOWS) || defined(FEAT_WILDMENU) || defined(FEAT_STL_OPT)
/*
 * Get the character to use in a status line.  Get its attributes in "*attr".
 */
    static int
fillchar_status(attr, is_curwin)
    int         *attr;
    int         is_curwin;
{
    int fill;
    if (is_curwin)
    {
        *attr = hl_attr(HLF_S);
        fill = fill_stl;
    }
    else
    {
        *attr = hl_attr(HLF_SNC);
        fill = fill_stlnc;
    }
    /* Use fill when there is highlighting, and highlighting of current
     * window differs, or the fillchars differ, or this is not the
     * current window */
    if (*attr != 0 && ((hl_attr(HLF_S) != hl_attr(HLF_SNC)
                        || !is_curwin || firstwin == lastwin)
                    || (fill_stl != fill_stlnc)))
        return fill;
    if (is_curwin)
        return '^';
    return '=';
}
#endif

#ifdef FEAT_VERTSPLIT
/*
 * Get the character to use in a separator between vertically split windows.
 * Get its attributes in "*attr".
 */
    static int
fillchar_vsep(attr)
    int     *attr;
{
    *attr = hl_attr(HLF_C);
    if (*attr == 0 && fill_vert == ' ')
        return '|';
    else
        return fill_vert;
}
#endif

/*
 * Return TRUE if redrawing should currently be done.
 */
    int
redrawing()
{
    return (!RedrawingDisabled
                       && !(p_lz && char_avail() && !KeyTyped && !do_redraw));
}

/*
 * Return TRUE if printing messages should currently be done.
 */
    int
messaging()
{
    return (!(p_lz && char_avail() && !KeyTyped));
}

/*
 * Show current status info in ruler and various other places
 * If always is FALSE, only show ruler if position has changed.
 */
    void
showruler(always)
    int     always;
{
    if (!always && !redrawing())
        return;
#ifdef FEAT_INS_EXPAND
    if (pum_visible())
    {
# ifdef FEAT_WINDOWS
        /* Don't redraw right now, do it later. */
        curwin->w_redr_status = TRUE;
# endif
        return;
    }
#endif
#if defined(FEAT_STL_OPT) && defined(FEAT_WINDOWS)
    if ((*p_stl != NUL || *curwin->w_p_stl != NUL) && curwin->w_status_height)
    {
        redraw_custum_statusline(curwin);
    }
    else
#endif
#ifdef FEAT_CMDL_INFO
        win_redr_ruler(curwin, always);
#endif

#ifdef FEAT_TITLE
    if (need_maketitle
# ifdef FEAT_STL_OPT
            || (p_icon && (stl_syntax & STL_IN_ICON))
            || (p_title && (stl_syntax & STL_IN_TITLE))
# endif
       )
        maketitle();
#endif
#ifdef FEAT_WINDOWS
    /* Redraw the tab pages line if needed. */
    if (redraw_tabline)
        draw_tabline();
#endif
}

#ifdef FEAT_CMDL_INFO
    static void
win_redr_ruler(wp, always)
    win_T       *wp;
    int         always;
{
    char_u      buffer[70];
    int         row;
    int         fillchar;
    int         attr;
    int         empty_line = FALSE;
    colnr_T     virtcol;
    int         i;
    int         o;
#ifdef FEAT_VERTSPLIT
    int         this_ru_col;
    int         off = 0;
    int         width = Columns;
# define WITH_OFF(x) x
# define WITH_WIDTH(x) x
#else
# define WITH_OFF(x) 0
# define WITH_WIDTH(x) Columns
# define this_ru_col ru_col
#endif

    /* If 'ruler' off or redrawing disabled, don't do anything */
    if (!p_ru)
        return;

    /*
     * Check if cursor.lnum is valid, since win_redr_ruler() may be called
     * after deleting lines, before cursor.lnum is corrected.
     */
    if (wp->w_cursor.lnum > wp->w_buffer->b_ml.ml_line_count)
        return;

#ifdef FEAT_INS_EXPAND
    /* Don't draw the ruler while doing insert-completion, it might overwrite
     * the (long) mode message. */
# ifdef FEAT_WINDOWS
    if (wp == lastwin && lastwin->w_status_height == 0)
# endif
        if (edit_submode != NULL)
            return;
    /* Don't draw the ruler when the popup menu is visible, it may overlap. */
    if (pum_visible())
        return;
#endif

#ifdef FEAT_STL_OPT
    if (*p_ruf)
    {
        int     save_called_emsg = called_emsg;

        called_emsg = FALSE;
        win_redr_custom(wp, TRUE);
        if (called_emsg)
            set_string_option_direct((char_u *)"rulerformat", -1,
                                           (char_u *)"", OPT_FREE, SID_ERROR);
        called_emsg |= save_called_emsg;
        return;
    }
#endif

    /*
     * Check if not in Insert mode and the line is empty (will show "0-1").
     */
    if (!(State & INSERT)
                && *ml_get_buf(wp->w_buffer, wp->w_cursor.lnum, FALSE) == NUL)
        empty_line = TRUE;

    /*
     * Only draw the ruler when something changed.
     */
    validate_virtcol_win(wp);
    if (       redraw_cmdline
            || always
            || wp->w_cursor.lnum != wp->w_ru_cursor.lnum
            || wp->w_cursor.col != wp->w_ru_cursor.col
            || wp->w_virtcol != wp->w_ru_virtcol
#ifdef FEAT_VIRTUALEDIT
            || wp->w_cursor.coladd != wp->w_ru_cursor.coladd
#endif
            || wp->w_topline != wp->w_ru_topline
            || wp->w_buffer->b_ml.ml_line_count != wp->w_ru_line_count
#ifdef FEAT_DIFF
            || wp->w_topfill != wp->w_ru_topfill
#endif
            || empty_line != wp->w_ru_empty)
    {
        cursor_off();
#ifdef FEAT_WINDOWS
        if (wp->w_status_height)
        {
            row = W_WINROW(wp) + wp->w_height;
            fillchar = fillchar_status(&attr, wp == curwin);
# ifdef FEAT_VERTSPLIT
            off = W_WINCOL(wp);
            width = W_WIDTH(wp);
# endif
        }
        else
#endif
        {
            row = Rows - 1;
            fillchar = ' ';
            attr = 0;
#ifdef FEAT_VERTSPLIT
            width = Columns;
            off = 0;
#endif
        }

        /* In list mode virtcol needs to be recomputed */
        virtcol = wp->w_virtcol;
        if (wp->w_p_list && lcs_tab1 == NUL)
        {
            wp->w_p_list = FALSE;
            getvvcol(wp, &wp->w_cursor, NULL, &virtcol, NULL);
            wp->w_p_list = TRUE;
        }

        /*
         * Some sprintfs return the length, some return a pointer.
         * To avoid portability problems we use strlen() here.
         */
        sprintf((char *)buffer, "%ld,",
                (wp->w_buffer->b_ml.ml_flags & ML_EMPTY)
                    ? 0L
                    : (long)(wp->w_cursor.lnum));
        col_print(buffer + STRLEN(buffer),
                        empty_line ? 0 : (int)wp->w_cursor.col + 1,
                        (int)virtcol + 1);

        /*
         * Add a "50%" if there is room for it.
         * On the last line, don't print in the last column (scrolls the
         * screen up on some terminals).
         */
        i = (int)STRLEN(buffer);
        get_rel_pos(wp, buffer + i + 1);
        o = i + vim_strsize(buffer + i + 1);
#ifdef FEAT_WINDOWS
        if (wp->w_status_height == 0)   /* can't use last char of screen */
#endif
            ++o;
#ifdef FEAT_VERTSPLIT
        this_ru_col = ru_col - (Columns - width);
        if (this_ru_col < 0)
            this_ru_col = 0;
#endif
        /* Never use more than half the window/screen width, leave the other
         * half for the filename. */
        if (this_ru_col < (WITH_WIDTH(width) + 1) / 2)
            this_ru_col = (WITH_WIDTH(width) + 1) / 2;
        if (this_ru_col + o < WITH_WIDTH(width))
        {
            while (this_ru_col + o < WITH_WIDTH(width))
            {
#ifdef FEAT_MBYTE
                if (has_mbyte)
                    i += (*mb_char2bytes)(fillchar, buffer + i);
                else
#endif
                    buffer[i++] = fillchar;
                ++o;
            }
            get_rel_pos(wp, buffer + i);
        }
        /* Truncate at window boundary. */
#ifdef FEAT_MBYTE
        if (has_mbyte)
        {
            o = 0;
            for (i = 0; buffer[i] != NUL; i += (*mb_ptr2len)(buffer + i))
            {
                o += (*mb_ptr2cells)(buffer + i);
                if (this_ru_col + o > WITH_WIDTH(width))
                {
                    buffer[i] = NUL;
                    break;
                }
            }
        }
        else
#endif
        if (this_ru_col + (int)STRLEN(buffer) > WITH_WIDTH(width))
            buffer[WITH_WIDTH(width) - this_ru_col] = NUL;

        screen_puts(buffer, row, this_ru_col + WITH_OFF(off), attr);
        i = redraw_cmdline;
        screen_fill(row, row + 1,
                this_ru_col + WITH_OFF(off) + (int)STRLEN(buffer),
                (int)(WITH_OFF(off) + WITH_WIDTH(width)),
                fillchar, fillchar, attr);
        /* don't redraw the cmdline because of showing the ruler */
        redraw_cmdline = i;
        wp->w_ru_cursor = wp->w_cursor;
        wp->w_ru_virtcol = wp->w_virtcol;
        wp->w_ru_empty = empty_line;
        wp->w_ru_topline = wp->w_topline;
        wp->w_ru_line_count = wp->w_buffer->b_ml.ml_line_count;
#ifdef FEAT_DIFF
        wp->w_ru_topfill = wp->w_topfill;
#endif
    }
}
#endif

#if defined(FEAT_LINEBREAK) || defined(PROTO)
/*
 * Return the width of the 'number' column.
 * Caller may need to check if 'number' is set.
 * Otherwise it depends on 'numberwidth' and the line count.
 */
    int
number_width(wp)
    win_T       *wp;
{
    int         n;
    linenr_T    lnum;

    lnum = wp->w_buffer->b_ml.ml_line_count;
    if (lnum == wp->w_nrwidth_line_count)
        return wp->w_nrwidth_width;
    wp->w_nrwidth_line_count = lnum;

    n = 0;
    do
    {
        lnum /= 10;
        ++n;
    } while (lnum > 0);

    /* 'numberwidth' gives the minimal width plus one */
    if (n < wp->w_p_nuw - 1)
        n = wp->w_p_nuw - 1;

    wp->w_nrwidth_width = n;
    return n;
}
#endif