Merge branch 'vim'

[MacVim.git] / src / mbyte.c

/* vi:set ts=8 sts=4 sw=4:
 *
 * VIM - Vi IMproved    by Bram Moolenaar
 * Multibyte extensions partly by Sung-Hoon Baek
 *
 * 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.
 */
/*
 * mbyte.c: Code specifically for handling multi-byte characters.
 *
 * The encoding used in the core is set with 'encoding'.  When 'encoding' is
 * changed, the following four variables are set (for speed).
 * Currently these types of character encodings are supported:
 *
 * "enc_dbcs"       When non-zero it tells the type of double byte character
 *                  encoding (Chinese, Korean, Japanese, etc.).
 *                  The cell width on the display is equal to the number of
 *                  bytes.  (exception: DBCS_JPNU with first byte 0x8e)
 *                  Recognizing the first or second byte is difficult, it
 *                  requires checking a byte sequence from the start.
 * "enc_utf8"       When TRUE use Unicode characters in UTF-8 encoding.
 *                  The cell width on the display needs to be determined from
 *                  the character value.
 *                  Recognizing bytes is easy: 0xxx.xxxx is a single-byte
 *                  char, 10xx.xxxx is a trailing byte, 11xx.xxxx is a leading
 *                  byte of a multi-byte character.
 *                  To make things complicated, up to two composing characters
 *                  are allowed.  These are drawn on top of the first char.
 *                  For most editing the sequence of bytes with composing
 *                  characters included is considered to be one character.
 * "enc_unicode"    When 2 use 16-bit Unicode characters (or UTF-16).
 *                  When 4 use 32-but Unicode characters.
 *                  Internally characters are stored in UTF-8 encoding to
 *                  avoid NUL bytes.  Conversion happens when doing I/O.
 *                  "enc_utf8" will also be TRUE.
 *
 * "has_mbyte" is set when "enc_dbcs" or "enc_utf8" is non-zero.
 *
 * If none of these is TRUE, 8-bit bytes are used for a character.  The
 * encoding isn't currently specified (TODO).
 *
 * 'encoding' specifies the encoding used in the core.  This is in registers,
 * text manipulation, buffers, etc.  Conversion has to be done when characters
 * in another encoding are received or send:
 *
 *                     clipboard
 *                         ^
 *                         | (2)
 *                         V
 *                 +---------------+
 *            (1)  |               | (3)
 *  keyboard ----->|     core      |-----> display
 *                 |               |
 *                 +---------------+
 *                         ^
 *                         | (4)
 *                         V
 *                       file
 *
 * (1) Typed characters arrive in the current locale.  Conversion is to be
 *     done when 'encoding' is different from 'termencoding'.
 * (2) Text will be made available with the encoding specified with
 *     'encoding'.  If this is not sufficient, system-specific conversion
 *     might be required.
 * (3) For the GUI the correct font must be selected, no conversion done.
 *     Otherwise, conversion is to be done when 'encoding' differs from
 *     'termencoding'.  (Different in the GTK+ 2 port -- 'termencoding'
 *     is always used for both input and output and must always be set to
 *     "utf-8".  gui_mch_init() does this automatically.)
 * (4) The encoding of the file is specified with 'fileencoding'.  Conversion
 *     is to be done when it's different from 'encoding'.
 *
 * The viminfo file is a special case: Only text is converted, not file names.
 * Vim scripts may contain an ":encoding" command.  This has an effect for
 * some commands, like ":menutrans"
 */

#include "vim.h"

#ifdef WIN32UNIX
# ifndef WIN32_LEAN_AND_MEAN
#  define WIN32_LEAN_AND_MEAN
# endif
# include <windows.h>
# ifdef WIN32
#  undef WIN32      /* Some windows.h define WIN32, we don't want that here. */
# endif
#endif

#if (defined(WIN3264) || defined(WIN32UNIX)) && !defined(__MINGW32__)
# include <winnls.h>
#endif

#ifdef FEAT_GUI_X11
# include <X11/Intrinsic.h>
#endif
#ifdef X_LOCALE
#include <X11/Xlocale.h>
#endif

#if defined(FEAT_GUI_GTK) && defined(FEAT_XIM) && defined(HAVE_GTK2)
# include <gdk/gdkkeysyms.h>
# ifdef WIN3264
#  include <gdk/gdkwin32.h>
# else
#  include <gdk/gdkx.h>
# endif
#endif

#ifdef HAVE_WCHAR_H
# include <wchar.h>
#endif

#if 0
/* This has been disabled, because several people reported problems with the
 * wcwidth() and iswprint() library functions, esp. for Hebrew. */
# ifdef __STDC_ISO_10646__
#  define USE_WCHAR_FUNCTIONS
# endif
#endif

#if defined(FEAT_MBYTE) || defined(PROTO)

static int enc_canon_search __ARGS((char_u *name));
static int dbcs_char2len __ARGS((int c));
static int dbcs_char2bytes __ARGS((int c, char_u *buf));
static int dbcs_ptr2len __ARGS((char_u *p));
static int dbcs_ptr2len_len __ARGS((char_u *p, int size));
static int utf_ptr2cells_len __ARGS((char_u *p, int size));
static int dbcs_char2cells __ARGS((int c));
static int dbcs_ptr2cells_len __ARGS((char_u *p, int size));
static int dbcs_ptr2char __ARGS((char_u *p));

/*
 * Lookup table to quickly get the length in bytes of a UTF-8 character from
 * the first byte of a UTF-8 string.
 * Bytes which are illegal when used as the first byte have a 1.
 * The NUL byte has length 1.
 */
static char utf8len_tab[256] =
{
    1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
    1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
    1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
    1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
    1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
    1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
    2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
    3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,4,4,4,4,4,4,4,4,5,5,5,5,6,6,1,1,
};

/*
 * Like utf8len_tab above, but using a zero for illegal lead bytes.
 */
static char utf8len_tab_zero[256] =
{
    1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
    1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
    1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
    1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
    0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
    0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
    2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
    3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,4,4,4,4,4,4,4,4,5,5,5,5,6,6,0,0,
};

/*
 * XIM often causes trouble.  Define XIM_DEBUG to get a log of XIM callbacks
 * in the "xim.log" file.
 */
/* #define XIM_DEBUG */
#ifdef XIM_DEBUG
    static void
xim_log(char *s, ...)
{
    va_list arglist;
    static FILE *fd = NULL;

    if (fd == (FILE *)-1)
        return;
    if (fd == NULL)
    {
        fd = mch_fopen("xim.log", "w");
        if (fd == NULL)
        {
            EMSG("Cannot open xim.log");
            fd = (FILE *)-1;
            return;
        }
    }

    va_start(arglist, s);
    vfprintf(fd, s, arglist);
    va_end(arglist);
}
#endif

#endif

#if defined(FEAT_MBYTE) || defined(FEAT_POSTSCRIPT) || defined(PROTO)
/*
 * Canonical encoding names and their properties.
 * "iso-8859-n" is handled by enc_canonize() directly.
 */
static struct
{   char *name;         int prop;               int codepage;}
enc_canon_table[] =
{
#define IDX_LATIN_1     0
    {"latin1",          ENC_8BIT + ENC_LATIN1,  1252},
#define IDX_ISO_2       1
    {"iso-8859-2",      ENC_8BIT,               0},
#define IDX_ISO_3       2
    {"iso-8859-3",      ENC_8BIT,               0},
#define IDX_ISO_4       3
    {"iso-8859-4",      ENC_8BIT,               0},
#define IDX_ISO_5       4
    {"iso-8859-5",      ENC_8BIT,               0},
#define IDX_ISO_6       5
    {"iso-8859-6",      ENC_8BIT,               0},
#define IDX_ISO_7       6
    {"iso-8859-7",      ENC_8BIT,               0},
#define IDX_ISO_8       7
    {"iso-8859-8",      ENC_8BIT,               0},
#define IDX_ISO_9       8
    {"iso-8859-9",      ENC_8BIT,               0},
#define IDX_ISO_10      9
    {"iso-8859-10",     ENC_8BIT,               0},
#define IDX_ISO_11      10
    {"iso-8859-11",     ENC_8BIT,               0},
#define IDX_ISO_13      11
    {"iso-8859-13",     ENC_8BIT,               0},
#define IDX_ISO_14      12
    {"iso-8859-14",     ENC_8BIT,               0},
#define IDX_ISO_15      13
    {"iso-8859-15",     ENC_8BIT + ENC_LATIN9,  0},
#define IDX_KOI8_R      14
    {"koi8-r",          ENC_8BIT,               0},
#define IDX_KOI8_U      15
    {"koi8-u",          ENC_8BIT,               0},
#define IDX_UTF8        16
    {"utf-8",           ENC_UNICODE,            0},
#define IDX_UCS2        17
    {"ucs-2",           ENC_UNICODE + ENC_ENDIAN_B + ENC_2BYTE, 0},
#define IDX_UCS2LE      18
    {"ucs-2le",         ENC_UNICODE + ENC_ENDIAN_L + ENC_2BYTE, 0},
#define IDX_UTF16       19
    {"utf-16",          ENC_UNICODE + ENC_ENDIAN_B + ENC_2WORD, 0},
#define IDX_UTF16LE     20
    {"utf-16le",        ENC_UNICODE + ENC_ENDIAN_L + ENC_2WORD, 0},
#define IDX_UCS4        21
    {"ucs-4",           ENC_UNICODE + ENC_ENDIAN_B + ENC_4BYTE, 0},
#define IDX_UCS4LE      22
    {"ucs-4le",         ENC_UNICODE + ENC_ENDIAN_L + ENC_4BYTE, 0},

    /* For debugging DBCS encoding on Unix. */
#define IDX_DEBUG       23
    {"debug",           ENC_DBCS,               DBCS_DEBUG},
#define IDX_EUC_JP      24
    {"euc-jp",          ENC_DBCS,               DBCS_JPNU},
#define IDX_SJIS        25
    {"sjis",            ENC_DBCS,               DBCS_JPN},
#define IDX_EUC_KR      26
    {"euc-kr",          ENC_DBCS,               DBCS_KORU},
#define IDX_EUC_CN      27
    {"euc-cn",          ENC_DBCS,               DBCS_CHSU},
#define IDX_EUC_TW      28
    {"euc-tw",          ENC_DBCS,               DBCS_CHTU},
#define IDX_BIG5        29
    {"big5",            ENC_DBCS,               DBCS_CHT},

    /* MS-DOS and MS-Windows codepages are included here, so that they can be
     * used on Unix too.  Most of them are similar to ISO-8859 encodings, but
     * not exactly the same. */
#define IDX_CP437       30
    {"cp437",           ENC_8BIT,               437}, /* like iso-8859-1 */
#define IDX_CP737       31
    {"cp737",           ENC_8BIT,               737}, /* like iso-8859-7 */
#define IDX_CP775       32
    {"cp775",           ENC_8BIT,               775}, /* Baltic */
#define IDX_CP850       33
    {"cp850",           ENC_8BIT,               850}, /* like iso-8859-4 */
#define IDX_CP852       34
    {"cp852",           ENC_8BIT,               852}, /* like iso-8859-1 */
#define IDX_CP855       35
    {"cp855",           ENC_8BIT,               855}, /* like iso-8859-2 */
#define IDX_CP857       36
    {"cp857",           ENC_8BIT,               857}, /* like iso-8859-5 */
#define IDX_CP860       37
    {"cp860",           ENC_8BIT,               860}, /* like iso-8859-9 */
#define IDX_CP861       38
    {"cp861",           ENC_8BIT,               861}, /* like iso-8859-1 */
#define IDX_CP862       39
    {"cp862",           ENC_8BIT,               862}, /* like iso-8859-1 */
#define IDX_CP863       40
    {"cp863",           ENC_8BIT,               863}, /* like iso-8859-8 */
#define IDX_CP865       41
    {"cp865",           ENC_8BIT,               865}, /* like iso-8859-1 */
#define IDX_CP866       42
    {"cp866",           ENC_8BIT,               866}, /* like iso-8859-5 */
#define IDX_CP869       43
    {"cp869",           ENC_8BIT,               869}, /* like iso-8859-7 */
#define IDX_CP874       44
    {"cp874",           ENC_8BIT,               874}, /* Thai */
#define IDX_CP932       45
    {"cp932",           ENC_DBCS,               DBCS_JPN},
#define IDX_CP936       46
    {"cp936",           ENC_DBCS,               DBCS_CHS},
#define IDX_CP949       47
    {"cp949",           ENC_DBCS,               DBCS_KOR},
#define IDX_CP950       48
    {"cp950",           ENC_DBCS,               DBCS_CHT},
#define IDX_CP1250      49
    {"cp1250",          ENC_8BIT,               1250}, /* Czech, Polish, etc. */
#define IDX_CP1251      50
    {"cp1251",          ENC_8BIT,               1251}, /* Cyrillic */
    /* cp1252 is considered to be equal to latin1 */
#define IDX_CP1253      51
    {"cp1253",          ENC_8BIT,               1253}, /* Greek */
#define IDX_CP1254      52
    {"cp1254",          ENC_8BIT,               1254}, /* Turkish */
#define IDX_CP1255      53
    {"cp1255",          ENC_8BIT,               1255}, /* Hebrew */
#define IDX_CP1256      54
    {"cp1256",          ENC_8BIT,               1256}, /* Arabic */
#define IDX_CP1257      55
    {"cp1257",          ENC_8BIT,               1257}, /* Baltic */
#define IDX_CP1258      56
    {"cp1258",          ENC_8BIT,               1258}, /* Vietnamese */

#define IDX_MACROMAN    57
    {"macroman",        ENC_8BIT + ENC_MACROMAN, 0},    /* Mac OS */
#define IDX_DECMCS      58
    {"dec-mcs",         ENC_8BIT,               0},     /* DEC MCS */
#define IDX_HPROMAN8    59
    {"hp-roman8",       ENC_8BIT,               0},     /* HP Roman8 */
#define IDX_COUNT       60
};

/*
 * Aliases for encoding names.
 */
static struct
{   char *name;         int canon;}
enc_alias_table[] =
{
    {"ansi",            IDX_LATIN_1},
    {"iso-8859-1",      IDX_LATIN_1},
    {"latin2",          IDX_ISO_2},
    {"latin3",          IDX_ISO_3},
    {"latin4",          IDX_ISO_4},
    {"cyrillic",        IDX_ISO_5},
    {"arabic",          IDX_ISO_6},
    {"greek",           IDX_ISO_7},
#ifdef WIN3264
    {"hebrew",          IDX_CP1255},
#else
    {"hebrew",          IDX_ISO_8},
#endif
    {"latin5",          IDX_ISO_9},
    {"turkish",         IDX_ISO_9}, /* ? */
    {"latin6",          IDX_ISO_10},
    {"nordic",          IDX_ISO_10}, /* ? */
    {"thai",            IDX_ISO_11}, /* ? */
    {"latin7",          IDX_ISO_13},
    {"latin8",          IDX_ISO_14},
    {"latin9",          IDX_ISO_15},
    {"utf8",            IDX_UTF8},
    {"unicode",         IDX_UCS2},
    {"ucs2",            IDX_UCS2},
    {"ucs2be",          IDX_UCS2},
    {"ucs-2be",         IDX_UCS2},
    {"ucs2le",          IDX_UCS2LE},
    {"utf16",           IDX_UTF16},
    {"utf16be",         IDX_UTF16},
    {"utf-16be",        IDX_UTF16},
    {"utf16le",         IDX_UTF16LE},
    {"ucs4",            IDX_UCS4},
    {"ucs4be",          IDX_UCS4},
    {"ucs-4be",         IDX_UCS4},
    {"ucs4le",          IDX_UCS4LE},
    {"utf32",           IDX_UCS4},
    {"utf-32",          IDX_UCS4},
    {"utf32be",         IDX_UCS4},
    {"utf-32be",        IDX_UCS4},
    {"utf32le",         IDX_UCS4LE},
    {"utf-32le",        IDX_UCS4LE},
    {"932",             IDX_CP932},
    {"949",             IDX_CP949},
    {"936",             IDX_CP936},
    {"gbk",             IDX_CP936},
    {"950",             IDX_CP950},
    {"eucjp",           IDX_EUC_JP},
    {"unix-jis",        IDX_EUC_JP},
    {"ujis",            IDX_EUC_JP},
    {"shift-jis",       IDX_SJIS},
    {"euckr",           IDX_EUC_KR},
    {"5601",            IDX_EUC_KR},    /* Sun: KS C 5601 */
    {"euccn",           IDX_EUC_CN},
    {"gb2312",          IDX_EUC_CN},
    {"euctw",           IDX_EUC_TW},
#if defined(WIN3264) || defined(WIN32UNIX) || defined(MACOS)
    {"japan",           IDX_CP932},
    {"korea",           IDX_CP949},
    {"prc",             IDX_CP936},
    {"chinese",         IDX_CP936},
    {"taiwan",          IDX_CP950},
    {"big5",            IDX_CP950},
#else
    {"japan",           IDX_EUC_JP},
    {"korea",           IDX_EUC_KR},
    {"prc",             IDX_EUC_CN},
    {"chinese",         IDX_EUC_CN},
    {"taiwan",          IDX_EUC_TW},
    {"cp950",           IDX_BIG5},
    {"950",             IDX_BIG5},
#endif
    {"mac",             IDX_MACROMAN},
    {"mac-roman",       IDX_MACROMAN},
    {NULL,              0}
};

#ifndef CP_UTF8
# define CP_UTF8 65001  /* magic number from winnls.h */
#endif

/*
 * Find encoding "name" in the list of canonical encoding names.
 * Returns -1 if not found.
 */
    static int
enc_canon_search(name)
    char_u      *name;
{
    int         i;

    for (i = 0; i < IDX_COUNT; ++i)
        if (STRCMP(name, enc_canon_table[i].name) == 0)
            return i;
    return -1;
}

#endif

#if defined(FEAT_MBYTE) || defined(PROTO)

/*
 * Find canonical encoding "name" in the list and return its properties.
 * Returns 0 if not found.
 */
    int
enc_canon_props(name)
    char_u      *name;
{
    int         i;

    i = enc_canon_search(name);
    if (i >= 0)
        return enc_canon_table[i].prop;
#ifdef WIN3264
    if (name[0] == 'c' && name[1] == 'p' && VIM_ISDIGIT(name[2]))
    {
        CPINFO  cpinfo;

        /* Get info on this codepage to find out what it is. */
        if (GetCPInfo(atoi(name + 2), &cpinfo) != 0)
        {
            if (cpinfo.MaxCharSize == 1) /* some single-byte encoding */
                return ENC_8BIT;
            if (cpinfo.MaxCharSize == 2
                    && (cpinfo.LeadByte[0] != 0 || cpinfo.LeadByte[1] != 0))
                /* must be a DBCS encoding */
                return ENC_DBCS;
        }
        return 0;
    }
#endif
    if (STRNCMP(name, "2byte-", 6) == 0)
        return ENC_DBCS;
    if (STRNCMP(name, "8bit-", 5) == 0 || STRNCMP(name, "iso-8859-", 9) == 0)
        return ENC_8BIT;
    return 0;
}

/*
 * Set up for using multi-byte characters.
 * Called in three cases:
 * - by main() to initialize (p_enc == NULL)
 * - by set_init_1() after 'encoding' was set to its default.
 * - by do_set() when 'encoding' has been set.
 * p_enc must have been passed through enc_canonize() already.
 * Sets the "enc_unicode", "enc_utf8", "enc_dbcs" and "has_mbyte" flags.
 * Fills mb_bytelen_tab[] and returns NULL when there are no problems.
 * When there is something wrong: Returns an error message and doesn't change
 * anything.
 */
    char_u *
mb_init()
{
    int         i;
    int         idx;
    int         n;
    int         enc_dbcs_new = 0;
#if defined(USE_ICONV) && !defined(WIN3264) && !defined(WIN32UNIX) \
        && !defined(MACOS)
# define LEN_FROM_CONV
    vimconv_T   vimconv;
    char_u      *p;
#endif

    if (p_enc == NULL)
    {
        /* Just starting up: set the whole table to one's. */
        for (i = 0; i < 256; ++i)
            mb_bytelen_tab[i] = 1;
        input_conv.vc_type = CONV_NONE;
        input_conv.vc_factor = 1;
        output_conv.vc_type = CONV_NONE;
        return NULL;
    }

#ifdef WIN3264
    if (p_enc[0] == 'c' && p_enc[1] == 'p' && VIM_ISDIGIT(p_enc[2]))
    {
        CPINFO  cpinfo;

        /* Get info on this codepage to find out what it is. */
        if (GetCPInfo(atoi(p_enc + 2), &cpinfo) != 0)
        {
            if (cpinfo.MaxCharSize == 1)
            {
                /* some single-byte encoding */
                enc_unicode = 0;
                enc_utf8 = FALSE;
            }
            else if (cpinfo.MaxCharSize == 2
                    && (cpinfo.LeadByte[0] != 0 || cpinfo.LeadByte[1] != 0))
            {
                /* must be a DBCS encoding, check below */
                enc_dbcs_new = atoi(p_enc + 2);
            }
            else
                goto codepage_invalid;
        }
        else if (GetLastError() == ERROR_INVALID_PARAMETER)
        {
codepage_invalid:
            return (char_u *)N_("E543: Not a valid codepage");
        }
    }
#endif
    else if (STRNCMP(p_enc, "8bit-", 5) == 0
            || STRNCMP(p_enc, "iso-8859-", 9) == 0)
    {
        /* Accept any "8bit-" or "iso-8859-" name. */
        enc_unicode = 0;
        enc_utf8 = FALSE;
    }
    else if (STRNCMP(p_enc, "2byte-", 6) == 0)
    {
#ifdef WIN3264
        /* Windows: accept only valid codepage numbers, check below. */
        if (p_enc[6] != 'c' || p_enc[7] != 'p'
                                      || (enc_dbcs_new = atoi(p_enc + 8)) == 0)
            return e_invarg;
#else
        /* Unix: accept any "2byte-" name, assume current locale. */
        enc_dbcs_new = DBCS_2BYTE;
#endif
    }
    else if ((idx = enc_canon_search(p_enc)) >= 0)
    {
        i = enc_canon_table[idx].prop;
        if (i & ENC_UNICODE)
        {
            /* Unicode */
            enc_utf8 = TRUE;
            if (i & (ENC_2BYTE | ENC_2WORD))
                enc_unicode = 2;
            else if (i & ENC_4BYTE)
                enc_unicode = 4;
            else
                enc_unicode = 0;
        }
        else if (i & ENC_DBCS)
        {
            /* 2byte, handle below */
            enc_dbcs_new = enc_canon_table[idx].codepage;
        }
        else
        {
            /* Must be 8-bit. */
            enc_unicode = 0;
            enc_utf8 = FALSE;
        }
    }
    else    /* Don't know what encoding this is, reject it. */
        return e_invarg;

    if (enc_dbcs_new != 0)
    {
#ifdef WIN3264
        /* Check if the DBCS code page is OK. */
        if (!IsValidCodePage(enc_dbcs_new))
            goto codepage_invalid;
#endif
        enc_unicode = 0;
        enc_utf8 = FALSE;
    }
    enc_dbcs = enc_dbcs_new;
    has_mbyte = (enc_dbcs != 0 || enc_utf8);

#ifdef WIN3264
    enc_codepage = encname2codepage(p_enc);
    enc_latin9 = (STRCMP(p_enc, "iso-8859-15") == 0);
#endif

    /* Detect an encoding that uses latin1 characters. */
    enc_latin1like = (enc_utf8 || STRCMP(p_enc, "latin1") == 0
                                        || STRCMP(p_enc, "iso-8859-15") == 0);

    /*
     * Set the function pointers.
     */
    if (enc_utf8)
    {
        mb_ptr2len = utfc_ptr2len;
        mb_ptr2len_len = utfc_ptr2len_len;
        mb_char2len = utf_char2len;
        mb_char2bytes = utf_char2bytes;
        mb_ptr2cells = utf_ptr2cells;
        mb_ptr2cells_len = utf_ptr2cells_len;
        mb_char2cells = utf_char2cells;
        mb_off2cells = utf_off2cells;
        mb_ptr2char = utf_ptr2char;
        mb_head_off = utf_head_off;
    }
    else if (enc_dbcs != 0)
    {
        mb_ptr2len = dbcs_ptr2len;
        mb_ptr2len_len = dbcs_ptr2len_len;
        mb_char2len = dbcs_char2len;
        mb_char2bytes = dbcs_char2bytes;
        mb_ptr2cells = dbcs_ptr2cells;
        mb_ptr2cells_len = dbcs_ptr2cells_len;
        mb_char2cells = dbcs_char2cells;
        mb_off2cells = dbcs_off2cells;
        mb_ptr2char = dbcs_ptr2char;
        mb_head_off = dbcs_head_off;
    }
    else
    {
        mb_ptr2len = latin_ptr2len;
        mb_ptr2len_len = latin_ptr2len_len;
        mb_char2len = latin_char2len;
        mb_char2bytes = latin_char2bytes;
        mb_ptr2cells = latin_ptr2cells;
        mb_ptr2cells_len = latin_ptr2cells_len;
        mb_char2cells = latin_char2cells;
        mb_off2cells = latin_off2cells;
        mb_ptr2char = latin_ptr2char;
        mb_head_off = latin_head_off;
    }

    /*
     * Fill the mb_bytelen_tab[] for MB_BYTE2LEN().
     */
#ifdef LEN_FROM_CONV
    /* When 'encoding' is different from the current locale mblen() won't
     * work.  Use conversion to "utf-8" instead. */
    vimconv.vc_type = CONV_NONE;
    if (enc_dbcs)
    {
        p = enc_locale();
        if (p == NULL || STRCMP(p, p_enc) != 0)
        {
            convert_setup(&vimconv, p_enc, (char_u *)"utf-8");
            vimconv.vc_fail = TRUE;
        }
        vim_free(p);
    }
#endif

    for (i = 0; i < 256; ++i)
    {
        /* Our own function to reliably check the length of UTF-8 characters,
         * independent of mblen(). */
        if (enc_utf8)
            n = utf8len_tab[i];
        else if (enc_dbcs == 0)
            n = 1;
        else
        {
#if defined(WIN3264) || defined(WIN32UNIX)
            /* enc_dbcs is set by setting 'fileencoding'.  It becomes a Windows
             * CodePage identifier, which we can pass directly in to Windows
             * API */
            n = IsDBCSLeadByteEx(enc_dbcs, (BYTE)i) ? 2 : 1;
#else
# if defined(MACOS) || defined(__amigaos4__)
            /*
             * if mblen() is not available, character which MSB is turned on
             * are treated as leading byte character. (note : This assumption
             * is not always true.)
             */
            n = (i & 0x80) ? 2 : 1;
# else
            char buf[MB_MAXBYTES];
# ifdef X_LOCALE
#  ifndef mblen
#   define mblen _Xmblen
#  endif
# endif
            if (i == NUL)       /* just in case mblen() can't handle "" */
                n = 1;
            else
            {
                buf[0] = i;
                buf[1] = 0;
#ifdef LEN_FROM_CONV
                if (vimconv.vc_type != CONV_NONE)
                {
                    /*
                     * string_convert() should fail when converting the first
                     * byte of a double-byte character.
                     */
                    p = string_convert(&vimconv, (char_u *)buf, NULL);
                    if (p != NULL)
                    {
                        vim_free(p);
                        n = 1;
                    }
                    else
                        n = 2;
                }
                else
#endif
                {
                    /*
                     * mblen() should return -1 for invalid (means the leading
                     * multibyte) character.  However there are some platforms
                     * where mblen() returns 0 for invalid character.
                     * Therefore, following condition includes 0.
                     */
                    ignored = mblen(NULL, 0);   /* First reset the state. */
                    if (mblen(buf, (size_t)1) <= 0)
                        n = 2;
                    else
                        n = 1;
                }
            }
# endif
#endif
        }

        mb_bytelen_tab[i] = n;
    }

#ifdef LEN_FROM_CONV
    convert_setup(&vimconv, NULL, NULL);
#endif

    /* The cell width depends on the type of multi-byte characters. */
    (void)init_chartab();

    /* When enc_utf8 is set or reset, (de)allocate ScreenLinesUC[] */
    screenalloc(FALSE);

    /* When using Unicode, set default for 'fileencodings'. */
    if (enc_utf8 && !option_was_set((char_u *)"fencs"))
        set_string_option_direct((char_u *)"fencs", -1,
                       (char_u *)"ucs-bom,utf-8,default,latin1", OPT_FREE, 0);

#if defined(HAVE_BIND_TEXTDOMAIN_CODESET) && defined(FEAT_GETTEXT)
    /* GNU gettext 0.10.37 supports this feature: set the codeset used for
     * translated messages independently from the current locale. */
    (void)bind_textdomain_codeset(VIMPACKAGE,
                                          enc_utf8 ? "utf-8" : (char *)p_enc);
#endif

#ifdef WIN32
    /* When changing 'encoding' while starting up, then convert the command
     * line arguments from the active codepage to 'encoding'. */
    if (starting != 0)
        fix_arg_enc();
#endif

#ifdef FEAT_AUTOCMD
    /* Fire an autocommand to let people do custom font setup. This must be
     * after Vim has been setup for the new encoding. */
    apply_autocmds(EVENT_ENCODINGCHANGED, NULL, (char_u *)"", FALSE, curbuf);
#endif

#ifdef FEAT_SPELL
    /* Need to reload spell dictionaries */
    spell_reload();
#endif

    return NULL;
}

/*
 * Return the size of the BOM for the current buffer:
 * 0 - no BOM
 * 2 - UCS-2 or UTF-16 BOM
 * 4 - UCS-4 BOM
 * 3 - UTF-8 BOM
 */
    int
bomb_size()
{
    int n = 0;

    if (curbuf->b_p_bomb && !curbuf->b_p_bin)
    {
        if (*curbuf->b_p_fenc == NUL)
        {
            if (enc_utf8)
            {
                if (enc_unicode != 0)
                    n = enc_unicode;
                else
                    n = 3;
            }
        }
        else if (STRCMP(curbuf->b_p_fenc, "utf-8") == 0)
            n = 3;
        else if (STRNCMP(curbuf->b_p_fenc, "ucs-2", 5) == 0
                || STRNCMP(curbuf->b_p_fenc, "utf-16", 6) == 0)
            n = 2;
        else if (STRNCMP(curbuf->b_p_fenc, "ucs-4", 5) == 0)
            n = 4;
    }
    return n;
}

/*
 * Get class of pointer:
 * 0 for blank or NUL
 * 1 for punctuation
 * 2 for an (ASCII) word character
 * >2 for other word characters
 */
    int
mb_get_class(p)
    char_u      *p;
{
    if (MB_BYTE2LEN(p[0]) == 1)
    {
        if (p[0] == NUL || vim_iswhite(p[0]))
            return 0;
        if (vim_iswordc(p[0]))
            return 2;
        return 1;
    }
    if (enc_dbcs != 0 && p[0] != NUL && p[1] != NUL)
        return dbcs_class(p[0], p[1]);
    if (enc_utf8)
        return utf_class(utf_ptr2char(p));
    return 0;
}

/*
 * Get class of a double-byte character.  This always returns 3 or bigger.
 * TODO: Should return 1 for punctuation.
 */
    int
dbcs_class(lead, trail)
    unsigned    lead;
    unsigned    trail;
{
    switch (enc_dbcs)
    {
        /* please add classfy routine for your language in here */

        case DBCS_JPNU: /* ? */
        case DBCS_JPN:
            {
                /* JIS code classification */
                unsigned char lb = lead;
                unsigned char tb = trail;

                /* convert process code to JIS */
# if defined(WIN3264) || defined(WIN32UNIX) || defined(MACOS)
                /* process code is SJIS */
                if (lb <= 0x9f)
                    lb = (lb - 0x81) * 2 + 0x21;
                else
                    lb = (lb - 0xc1) * 2 + 0x21;
                if (tb <= 0x7e)
                    tb -= 0x1f;
                else if (tb <= 0x9e)
                    tb -= 0x20;
                else
                {
                    tb -= 0x7e;
                    lb += 1;
                }
# else
                /*
                 * XXX: Code page identification can not use with all
                 *          system! So, some other encoding information
                 *          will be needed.
                 *          In japanese: SJIS,EUC,UNICODE,(JIS)
                 *          Note that JIS-code system don't use as
                 *          process code in most system because it uses
                 *          escape sequences(JIS is context depend encoding).
                 */
                /* assume process code is JAPANESE-EUC */
                lb &= 0x7f;
                tb &= 0x7f;
# endif
                /* exceptions */
                switch (lb << 8 | tb)
                {
                    case 0x2121: /* ZENKAKU space */
                        return 0;
                    case 0x2122: /* KU-TEN (Japanese comma) */
                    case 0x2123: /* TOU-TEN (Japanese period) */
                    case 0x2124: /* ZENKAKU comma */
                    case 0x2125: /* ZENKAKU period */
                        return 1;
                    case 0x213c: /* prolongedsound handled as KATAKANA */
                        return 13;
                }
                /* sieved by KU code */
                switch (lb)
                {
                    case 0x21:
                    case 0x22:
                        /* special symbols */
                        return 10;
                    case 0x23:
                        /* alpha-numeric */
                        return 11;
                    case 0x24:
                        /* hiragana */
                        return 12;
                    case 0x25:
                        /* katakana */
                        return 13;
                    case 0x26:
                        /* greek */
                        return 14;
                    case 0x27:
                        /* russian */
                        return 15;
                    case 0x28:
                        /* lines */
                        return 16;
                    default:
                        /* kanji */
                        return 17;
                }
            }

        case DBCS_KORU: /* ? */
        case DBCS_KOR:
            {
                /* KS code classification */
                unsigned char c1 = lead;
                unsigned char c2 = trail;

                /*
                 * 20 : Hangul
                 * 21 : Hanja
                 * 22 : Symbols
                 * 23 : Alpha-numeric/Roman Letter (Full width)
                 * 24 : Hangul Letter(Alphabet)
                 * 25 : Roman Numeral/Greek Letter
                 * 26 : Box Drawings
                 * 27 : Unit Symbols
                 * 28 : Circled/Parenthesized Letter
                 * 29 : Hirigana/Katakana
                 * 30 : Cyrillic Letter
                 */

                if (c1 >= 0xB0 && c1 <= 0xC8)
                    /* Hangul */
                    return 20;
#if defined(WIN3264) || defined(WIN32UNIX)
                else if (c1 <= 0xA0 || c2 <= 0xA0)
                    /* Extended Hangul Region : MS UHC(Unified Hangul Code) */
                    /* c1: 0x81-0xA0 with c2: 0x41-0x5A, 0x61-0x7A, 0x81-0xFE
                     * c1: 0xA1-0xC6 with c2: 0x41-0x5A, 0x61-0x7A, 0x81-0xA0
                     */
                    return 20;
#endif

                else if (c1 >= 0xCA && c1 <= 0xFD)
                    /* Hanja */
                    return 21;
                else switch (c1)
                {
                    case 0xA1:
                    case 0xA2:
                        /* Symbols */
                        return 22;
                    case 0xA3:
                        /* Alpha-numeric */
                        return 23;
                    case 0xA4:
                        /* Hangul Letter(Alphabet) */
                        return 24;
                    case 0xA5:
                        /* Roman Numeral/Greek Letter */
                        return 25;
                    case 0xA6:
                        /* Box Drawings */
                        return 26;
                    case 0xA7:
                        /* Unit Symbols */
                        return 27;
                    case 0xA8:
                    case 0xA9:
                        if (c2 <= 0xAF)
                            return 25;  /* Roman Letter */
                        else if (c2 >= 0xF6)
                            return 22;  /* Symbols */
                        else
                            /* Circled/Parenthesized Letter */
                            return 28;
                    case 0xAA:
                    case 0xAB:
                        /* Hirigana/Katakana */
                        return 29;
                    case 0xAC:
                        /* Cyrillic Letter */
                        return 30;
                }
            }
        default:
            break;
    }
    return 3;
}

/*
 * mb_char2len() function pointer.
 * Return length in bytes of character "c".
 * Returns 1 for a single-byte character.
 */
    int
latin_char2len(c)
    int         c UNUSED;
{
    return 1;
}

    static int
dbcs_char2len(c)
    int         c;
{
    if (c >= 0x100)
        return 2;
    return 1;
}

/*
 * mb_char2bytes() function pointer.
 * Convert a character to its bytes.
 * Returns the length in bytes.
 */
    int
latin_char2bytes(c, buf)
    int         c;
    char_u      *buf;
{
    buf[0] = c;
    return 1;
}

    static int
dbcs_char2bytes(c, buf)
    int         c;
    char_u      *buf;
{
    if (c >= 0x100)
    {
        buf[0] = (unsigned)c >> 8;
        buf[1] = c;
        /* Never use a NUL byte, it causes lots of trouble.  It's an invalid
         * character anyway. */
        if (buf[1] == NUL)
            buf[1] = '\n';
        return 2;
    }
    buf[0] = c;
    return 1;
}

/*
 * mb_ptr2len() function pointer.
 * Get byte length of character at "*p" but stop at a NUL.
 * For UTF-8 this includes following composing characters.
 * Returns 0 when *p is NUL.
 */
    int
latin_ptr2len(p)
    char_u      *p;
{
    return MB_BYTE2LEN(*p);
}

    static int
dbcs_ptr2len(p)
    char_u      *p;
{
    int         len;

    /* Check if second byte is not missing. */
    len = MB_BYTE2LEN(*p);
    if (len == 2 && p[1] == NUL)
        len = 1;
    return len;
}

/*
 * mb_ptr2len_len() function pointer.
 * Like mb_ptr2len(), but limit to read "size" bytes.
 * Returns 0 for an empty string.
 * Returns 1 for an illegal char or an incomplete byte sequence.
 */
    int
latin_ptr2len_len(p, size)
    char_u      *p;
    int         size;
{
    if (size < 1 || *p == NUL)
        return 0;
    return 1;
}

    static int
dbcs_ptr2len_len(p, size)
    char_u      *p;
    int         size;
{
    int         len;

    if (size < 1 || *p == NUL)
        return 0;
    if (size == 1)
        return 1;
    /* Check that second byte is not missing. */
    len = MB_BYTE2LEN(*p);
    if (len == 2 && p[1] == NUL)
        len = 1;
    return len;
}

struct interval
{
    unsigned short first;
    unsigned short last;
};
static int intable __ARGS((struct interval *table, size_t size, int c));

/*
 * Return TRUE if "c" is in "table[size / sizeof(struct interval)]".
 */
    static int
intable(table, size, c)
    struct interval     *table;
    size_t              size;
    int                 c;
{
    int mid, bot, top;

    /* first quick check for Latin1 etc. characters */
    if (c < table[0].first)
        return FALSE;

    /* binary search in table */
    bot = 0;
    top = (int)(size / sizeof(struct interval) - 1);
    while (top >= bot)
    {
        mid = (bot + top) / 2;
        if (table[mid].last < c)
            bot = mid + 1;
        else if (table[mid].first > c)
            top = mid - 1;
        else
            return TRUE;
    }
    return FALSE;
}

/*
 * For UTF-8 character "c" return 2 for a double-width character, 1 for others.
 * Returns 4 or 6 for an unprintable character.
 * Is only correct for characters >= 0x80.
 * When p_ambw is "double", return 2 for a character with East Asian Width
 * class 'A'(mbiguous).
 */
    int
utf_char2cells(c)
    int         c;
{
    /* sorted list of non-overlapping intervals of East Asian Ambiguous
     * characters, generated with:
     * "uniset +WIDTH-A -cat=Me -cat=Mn -cat=Cf c" */
    static struct interval ambiguous[] = {
        {0x00A1, 0x00A1}, {0x00A4, 0x00A4}, {0x00A7, 0x00A8},
        {0x00AA, 0x00AA}, {0x00AE, 0x00AE}, {0x00B0, 0x00B4},
        {0x00B6, 0x00BA}, {0x00BC, 0x00BF}, {0x00C6, 0x00C6},
        {0x00D0, 0x00D0}, {0x00D7, 0x00D8}, {0x00DE, 0x00E1},
        {0x00E6, 0x00E6}, {0x00E8, 0x00EA}, {0x00EC, 0x00ED},
        {0x00F0, 0x00F0}, {0x00F2, 0x00F3}, {0x00F7, 0x00FA},
        {0x00FC, 0x00FC}, {0x00FE, 0x00FE}, {0x0101, 0x0101},
        {0x0111, 0x0111}, {0x0113, 0x0113}, {0x011B, 0x011B},
        {0x0126, 0x0127}, {0x012B, 0x012B}, {0x0131, 0x0133},
        {0x0138, 0x0138}, {0x013F, 0x0142}, {0x0144, 0x0144},
        {0x0148, 0x014B}, {0x014D, 0x014D}, {0x0152, 0x0153},
        {0x0166, 0x0167}, {0x016B, 0x016B}, {0x01CE, 0x01CE},
        {0x01D0, 0x01D0}, {0x01D2, 0x01D2}, {0x01D4, 0x01D4},
        {0x01D6, 0x01D6}, {0x01D8, 0x01D8}, {0x01DA, 0x01DA},
        {0x01DC, 0x01DC}, {0x0251, 0x0251}, {0x0261, 0x0261},
        {0x02C4, 0x02C4}, {0x02C7, 0x02C7}, {0x02C9, 0x02CB},
        {0x02CD, 0x02CD}, {0x02D0, 0x02D0}, {0x02D8, 0x02DB},
        {0x02DD, 0x02DD}, {0x02DF, 0x02DF}, {0x0391, 0x03A1},
        {0x03A3, 0x03A9}, {0x03B1, 0x03C1}, {0x03C3, 0x03C9},
        {0x0401, 0x0401}, {0x0410, 0x044F}, {0x0451, 0x0451},
        {0x2010, 0x2010}, {0x2013, 0x2016}, {0x2018, 0x2019},
        {0x201C, 0x201D}, {0x2020, 0x2022}, {0x2024, 0x2027},
        {0x2030, 0x2030}, {0x2032, 0x2033}, {0x2035, 0x2035},
        {0x203B, 0x203B}, {0x203E, 0x203E}, {0x2074, 0x2074},
        {0x207F, 0x207F}, {0x2081, 0x2084}, {0x20AC, 0x20AC},
        {0x2103, 0x2103}, {0x2105, 0x2105}, {0x2109, 0x2109},
        {0x2113, 0x2113}, {0x2116, 0x2116}, {0x2121, 0x2122},
        {0x2126, 0x2126}, {0x212B, 0x212B}, {0x2153, 0x2154},
        {0x215B, 0x215E}, {0x2160, 0x216B}, {0x2170, 0x2179},
        {0x2190, 0x2199}, {0x21B8, 0x21B9}, {0x21D2, 0x21D2},
        {0x21D4, 0x21D4}, {0x21E7, 0x21E7}, {0x2200, 0x2200},
        {0x2202, 0x2203}, {0x2207, 0x2208}, {0x220B, 0x220B},
        {0x220F, 0x220F}, {0x2211, 0x2211}, {0x2215, 0x2215},
        {0x221A, 0x221A}, {0x221D, 0x2220}, {0x2223, 0x2223},
        {0x2225, 0x2225}, {0x2227, 0x222C}, {0x222E, 0x222E},
        {0x2234, 0x2237}, {0x223C, 0x223D}, {0x2248, 0x2248},
        {0x224C, 0x224C}, {0x2252, 0x2252}, {0x2260, 0x2261},
        {0x2264, 0x2267}, {0x226A, 0x226B}, {0x226E, 0x226F},
        {0x2282, 0x2283}, {0x2286, 0x2287}, {0x2295, 0x2295},
        {0x2299, 0x2299}, {0x22A5, 0x22A5}, {0x22BF, 0x22BF},
        {0x2312, 0x2312}, {0x2460, 0x24E9}, {0x24EB, 0x254B},
        {0x2550, 0x2573}, {0x2580, 0x258F}, {0x2592, 0x2595},
        {0x25A0, 0x25A1}, {0x25A3, 0x25A9}, {0x25B2, 0x25B3},
        {0x25B6, 0x25B7}, {0x25BC, 0x25BD}, {0x25C0, 0x25C1},
        {0x25C6, 0x25C8}, {0x25CB, 0x25CB}, {0x25CE, 0x25D1},
        {0x25E2, 0x25E5}, {0x25EF, 0x25EF}, {0x2605, 0x2606},
        {0x2609, 0x2609}, {0x260E, 0x260F}, {0x2614, 0x2615},
        {0x261C, 0x261C}, {0x261E, 0x261E}, {0x2640, 0x2640},
        {0x2642, 0x2642}, {0x2660, 0x2661}, {0x2663, 0x2665},
        {0x2667, 0x266A}, {0x266C, 0x266D}, {0x266F, 0x266F},
        {0x273D, 0x273D}, {0x2776, 0x277F}, {0xE000, 0xF8FF},
        {0xFFFD, 0xFFFD}, /* {0xF0000, 0xFFFFD}, {0x100000, 0x10FFFD} */
    };

    if (c >= 0x100)
    {
#ifdef USE_WCHAR_FUNCTIONS
        /*
         * Assume the library function wcwidth() works better than our own
         * stuff.  It should return 1 for ambiguous width chars!
         */
        int     n = wcwidth(c);

        if (n < 0)
            return 6;           /* unprintable, displays <xxxx> */
        if (n > 1)
            return n;
#else
        if (!utf_printable(c))
            return 6;           /* unprintable, displays <xxxx> */
        if (c >= 0x1100
            && (c <= 0x115f                     /* Hangul Jamo */
                || c == 0x2329
                || c == 0x232a
                || (c >= 0x2e80 && c <= 0xa4cf
                    && c != 0x303f)             /* CJK ... Yi */
                || (c >= 0xac00 && c <= 0xd7a3) /* Hangul Syllables */
                || (c >= 0xf900 && c <= 0xfaff) /* CJK Compatibility
                                                   Ideographs */
                || (c >= 0xfe30 && c <= 0xfe6f) /* CJK Compatibility Forms */
                || (c >= 0xff00 && c <= 0xff60) /* Fullwidth Forms */
                || (c >= 0xffe0 && c <= 0xffe6)
                || (c >= 0x20000 && c <= 0x2fffd)
                || (c >= 0x30000 && c <= 0x3fffd)))
            return 2;
#endif
    }

    /* Characters below 0x100 are influenced by 'isprint' option */
    else if (c >= 0x80 && !vim_isprintc(c))
        return 4;               /* unprintable, displays <xx> */

    if (c >= 0x80 && *p_ambw == 'd' && intable(ambiguous, sizeof(ambiguous), c))
        return 2;

    return 1;
}

/*
 * mb_ptr2cells() function pointer.
 * Return the number of display cells character at "*p" occupies.
 * This doesn't take care of unprintable characters, use ptr2cells() for that.
 */
    int
latin_ptr2cells(p)
    char_u      *p UNUSED;
{
    return 1;
}

    int
utf_ptr2cells(p)
    char_u      *p;
{
    int         c;

    /* Need to convert to a wide character. */
    if (*p >= 0x80)
    {
        c = utf_ptr2char(p);
        /* An illegal byte is displayed as <xx>. */
        if (utf_ptr2len(p) == 1 || c == NUL)
            return 4;
        /* If the char is ASCII it must be an overlong sequence. */
        if (c < 0x80)
            return char2cells(c);
        return utf_char2cells(c);
    }
    return 1;
}

    int
dbcs_ptr2cells(p)
    char_u      *p;
{
    /* Number of cells is equal to number of bytes, except for euc-jp when
     * the first byte is 0x8e. */
    if (enc_dbcs == DBCS_JPNU && *p == 0x8e)
        return 1;
    return MB_BYTE2LEN(*p);
}

/*
 * mb_ptr2cells_len() function pointer.
 * Like mb_ptr2cells(), but limit string length to "size".
 * For an empty string or truncated character returns 1.
 */
    int
latin_ptr2cells_len(p, size)
    char_u      *p UNUSED;
    int         size UNUSED;
{
    return 1;
}

    static int
utf_ptr2cells_len(p, size)
    char_u      *p;
    int         size;
{
    int         c;

    /* Need to convert to a wide character. */
    if (size > 0 && *p >= 0x80)
    {
        if (utf_ptr2len_len(p, size) < utf8len_tab[*p])
            return 1;  /* truncated */
        c = utf_ptr2char(p);
        /* An illegal byte is displayed as <xx>. */
        if (utf_ptr2len(p) == 1 || c == NUL)
            return 4;
        /* If the char is ASCII it must be an overlong sequence. */
        if (c < 0x80)
            return char2cells(c);
        return utf_char2cells(c);
    }
    return 1;
}

    static int
dbcs_ptr2cells_len(p, size)
    char_u      *p;
    int         size;
{
    /* Number of cells is equal to number of bytes, except for euc-jp when
     * the first byte is 0x8e. */
    if (size <= 1 || (enc_dbcs == DBCS_JPNU && *p == 0x8e))
        return 1;
    return MB_BYTE2LEN(*p);
}

/*
 * mb_char2cells() function pointer.
 * Return the number of display cells character "c" occupies.
 * Only takes care of multi-byte chars, not "^C" and such.
 */
    int
latin_char2cells(c)
    int         c UNUSED;
{
    return 1;
}

    static int
dbcs_char2cells(c)
    int         c;
{
    /* Number of cells is equal to number of bytes, except for euc-jp when
     * the first byte is 0x8e. */
    if (enc_dbcs == DBCS_JPNU && ((unsigned)c >> 8) == 0x8e)
        return 1;
    /* use the first byte */
    return MB_BYTE2LEN((unsigned)c >> 8);
}

/*
 * mb_off2cells() function pointer.
 * Return number of display cells for char at ScreenLines[off].
 * We make sure that the offset used is less than "max_off".
 */
    int
latin_off2cells(off, max_off)
    unsigned    off UNUSED;
    unsigned    max_off UNUSED;
{
    return 1;
}

    int
dbcs_off2cells(off, max_off)
    unsigned    off;
    unsigned    max_off;
{
    /* never check beyond end of the line */
    if (off >= max_off)
        return 1;

    /* Number of cells is equal to number of bytes, except for euc-jp when
     * the first byte is 0x8e. */
    if (enc_dbcs == DBCS_JPNU && ScreenLines[off] == 0x8e)
        return 1;
    return MB_BYTE2LEN(ScreenLines[off]);
}

    int
utf_off2cells(off, max_off)
    unsigned    off;
    unsigned    max_off;
{
    return (off + 1 < max_off && ScreenLines[off + 1] == 0) ? 2 : 1;
}

/*
 * mb_ptr2char() function pointer.
 * Convert a byte sequence into a character.
 */
    int
latin_ptr2char(p)
    char_u      *p;
{
    return *p;
}

    static int
dbcs_ptr2char(p)
    char_u      *p;
{
    if (MB_BYTE2LEN(*p) > 1 && p[1] != NUL)
        return (p[0] << 8) + p[1];
    return *p;
}

/*
 * Convert a UTF-8 byte sequence to a wide character.
 * If the sequence is illegal or truncated by a NUL the first byte is
 * returned.
 * Does not include composing characters, of course.
 */
    int
utf_ptr2char(p)
    char_u      *p;
{
    int         len;

    if (p[0] < 0x80)    /* be quick for ASCII */
        return p[0];

    len = utf8len_tab_zero[p[0]];
    if (len > 1 && (p[1] & 0xc0) == 0x80)
    {
        if (len == 2)
            return ((p[0] & 0x1f) << 6) + (p[1] & 0x3f);
        if ((p[2] & 0xc0) == 0x80)
        {
            if (len == 3)
                return ((p[0] & 0x0f) << 12) + ((p[1] & 0x3f) << 6)
                    + (p[2] & 0x3f);
            if ((p[3] & 0xc0) == 0x80)
            {
                if (len == 4)
                    return ((p[0] & 0x07) << 18) + ((p[1] & 0x3f) << 12)
                        + ((p[2] & 0x3f) << 6) + (p[3] & 0x3f);
                if ((p[4] & 0xc0) == 0x80)
                {
                    if (len == 5)
                        return ((p[0] & 0x03) << 24) + ((p[1] & 0x3f) << 18)
                            + ((p[2] & 0x3f) << 12) + ((p[3] & 0x3f) << 6)
                            + (p[4] & 0x3f);
                    if ((p[5] & 0xc0) == 0x80 && len == 6)
                        return ((p[0] & 0x01) << 30) + ((p[1] & 0x3f) << 24)
                            + ((p[2] & 0x3f) << 18) + ((p[3] & 0x3f) << 12)
                            + ((p[4] & 0x3f) << 6) + (p[5] & 0x3f);
                }
            }
        }
    }
    /* Illegal value, just return the first byte */
    return p[0];
}

/*
 * Get character at **pp and advance *pp to the next character.
 * Note: composing characters are skipped!
 */
    int
mb_ptr2char_adv(pp)
    char_u      **pp;
{
    int         c;

    c = (*mb_ptr2char)(*pp);
    *pp += (*mb_ptr2len)(*pp);
    return c;
}

/*
 * Get character at **pp and advance *pp to the next character.
 * Note: composing characters are returned as separate characters.
 */
    int
mb_cptr2char_adv(pp)
    char_u      **pp;
{
    int         c;

    c = (*mb_ptr2char)(*pp);
    if (enc_utf8)
        *pp += utf_ptr2len(*pp);
    else
        *pp += (*mb_ptr2len)(*pp);
    return c;
}

#if defined(FEAT_ARABIC) || defined(PROTO)
/*
 * Check whether we are dealing with Arabic combining characters.
 * Note: these are NOT really composing characters!
 */
    int
arabic_combine(one, two)
    int         one;        /* first character */
    int         two;        /* character just after "one" */
{
    if (one == a_LAM)
        return arabic_maycombine(two);
    return FALSE;
}

/*
 * Check whether we are dealing with a character that could be regarded as an
 * Arabic combining character, need to check the character before this.
 */
    int
arabic_maycombine(two)
    int         two;
{
    if (p_arshape && !p_tbidi)
        return (two == a_ALEF_MADDA
                    || two == a_ALEF_HAMZA_ABOVE
                    || two == a_ALEF_HAMZA_BELOW
                    || two == a_ALEF);
    return FALSE;
}

/*
 * Check if the character pointed to by "p2" is a composing character when it
 * comes after "p1".  For Arabic sometimes "ab" is replaced with "c", which
 * behaves like a composing character.
 */
    int
utf_composinglike(p1, p2)
    char_u      *p1;
    char_u      *p2;
{
    int         c2;

    c2 = utf_ptr2char(p2);
    if (utf_iscomposing(c2))
        return TRUE;
    if (!arabic_maycombine(c2))
        return FALSE;
    return arabic_combine(utf_ptr2char(p1), c2);
}
#endif

/*
 * Convert a UTF-8 byte string to a wide character.  Also get up to MAX_MCO
 * composing characters.
 */
    int
utfc_ptr2char(p, pcc)
    char_u      *p;
    int         *pcc;   /* return: composing chars, last one is 0 */
{
    int         len;
    int         c;
    int         cc;
    int         i = 0;

    c = utf_ptr2char(p);
    len = utf_ptr2len(p);

    /* Only accept a composing char when the first char isn't illegal. */
    if ((len > 1 || *p < 0x80)
            && p[len] >= 0x80
            && UTF_COMPOSINGLIKE(p, p + len))
    {
        cc = utf_ptr2char(p + len);
        for (;;)
        {
            pcc[i++] = cc;
            if (i == MAX_MCO)
                break;
            len += utf_ptr2len(p + len);
            if (p[len] < 0x80 || !utf_iscomposing(cc = utf_ptr2char(p + len)))
                break;
        }
    }

    if (i < MAX_MCO)    /* last composing char must be 0 */
        pcc[i] = 0;

    return c;
}

/*
 * Convert a UTF-8 byte string to a wide character.  Also get up to MAX_MCO
 * composing characters.  Use no more than p[maxlen].
 */
    int
utfc_ptr2char_len(p, pcc, maxlen)
    char_u      *p;
    int         *pcc;   /* return: composing chars, last one is 0 */
    int         maxlen;
{
    int         len;
    int         c;
    int         cc;
    int         i = 0;

    c = utf_ptr2char(p);
    len = utf_ptr2len_len(p, maxlen);
    /* Only accept a composing char when the first char isn't illegal. */
    if ((len > 1 || *p < 0x80)
            && len < maxlen
            && p[len] >= 0x80
            && UTF_COMPOSINGLIKE(p, p + len))
    {
        cc = utf_ptr2char(p + len);
        for (;;)
        {
            pcc[i++] = cc;
            if (i == MAX_MCO)
                break;
            len += utf_ptr2len_len(p + len, maxlen - len);
            if (len >= maxlen
                    || p[len] < 0x80
                    || !utf_iscomposing(cc = utf_ptr2char(p + len)))
                break;
        }
    }

    if (i < MAX_MCO)    /* last composing char must be 0 */
        pcc[i] = 0;

    return c;
}

/*
 * Convert the character at screen position "off" to a sequence of bytes.
 * Includes the composing characters.
 * "buf" must at least have the length MB_MAXBYTES.
 * Returns the produced number of bytes.
 */
    int
utfc_char2bytes(off, buf)
    int         off;
    char_u      *buf;
{
    int         len;
    int         i;

    len = utf_char2bytes(ScreenLinesUC[off], buf);
    for (i = 0; i < Screen_mco; ++i)
    {
        if (ScreenLinesC[i][off] == 0)
            break;
        len += utf_char2bytes(ScreenLinesC[i][off], buf + len);
    }
    return len;
}

/*
 * Get the length of a UTF-8 byte sequence, not including any following
 * composing characters.
 * Returns 0 for "".
 * Returns 1 for an illegal byte sequence.
 */
    int
utf_ptr2len(p)
    char_u      *p;
{
    int         len;
    int         i;

    if (*p == NUL)
        return 0;
    len = utf8len_tab[*p];
    for (i = 1; i < len; ++i)
        if ((p[i] & 0xc0) != 0x80)
            return 1;
    return len;
}

/*
 * Return length of UTF-8 character, obtained from the first byte.
 * "b" must be between 0 and 255!
 * Returns 1 for an invalid first byte value.
 */
    int
utf_byte2len(b)
    int         b;
{
    return utf8len_tab[b];
}

/*
 * Get the length of UTF-8 byte sequence "p[size]".  Does not include any
 * following composing characters.
 * Returns 1 for "".
 * Returns 1 for an illegal byte sequence (also in incomplete byte seq.).
 * Returns number > "size" for an incomplete byte sequence.
 * Never returns zero.
 */
    int
utf_ptr2len_len(p, size)
    char_u      *p;
    int         size;
{
    int         len;
    int         i;
    int         m;

    len = utf8len_tab[*p];
    if (len == 1)
        return 1;       /* NUL, ascii or illegal lead byte */
    if (len > size)
        m = size;       /* incomplete byte sequence. */
    else
        m = len;
    for (i = 1; i < m; ++i)
        if ((p[i] & 0xc0) != 0x80)
            return 1;
    return len;
}

/*
 * Return the number of bytes the UTF-8 encoding of the character at "p" takes.
 * This includes following composing characters.
 */
    int
utfc_ptr2len(p)
    char_u      *p;
{
    int         len;
    int         b0 = *p;
#ifdef FEAT_ARABIC
    int         prevlen;
#endif

    if (b0 == NUL)
        return 0;
    if (b0 < 0x80 && p[1] < 0x80)       /* be quick for ASCII */
        return 1;

    /* Skip over first UTF-8 char, stopping at a NUL byte. */
    len = utf_ptr2len(p);

    /* Check for illegal byte. */
    if (len == 1 && b0 >= 0x80)
        return 1;

    /*
     * Check for composing characters.  We can handle only the first two, but
     * skip all of them (otherwise the cursor would get stuck).
     */
#ifdef FEAT_ARABIC
    prevlen = 0;
#endif
    for (;;)
    {
        if (p[len] < 0x80 || !UTF_COMPOSINGLIKE(p + prevlen, p + len))
            return len;

        /* Skip over composing char */
#ifdef FEAT_ARABIC
        prevlen = len;
#endif
        len += utf_ptr2len(p + len);
    }
}

/*
 * Return the number of bytes the UTF-8 encoding of the character at "p[size]"
 * takes.  This includes following composing characters.
 * Returns 0 for an empty string.
 * Returns 1 for an illegal char or an incomplete byte sequence.
 */
    int
utfc_ptr2len_len(p, size)
    char_u      *p;
    int         size;
{
    int         len;
#ifdef FEAT_ARABIC
    int         prevlen;
#endif

    if (size < 1 || *p == NUL)
        return 0;
    if (p[0] < 0x80 && (size == 1 || p[1] < 0x80)) /* be quick for ASCII */
        return 1;

    /* Skip over first UTF-8 char, stopping at a NUL byte. */
    len = utf_ptr2len_len(p, size);

    /* Check for illegal byte and incomplete byte sequence. */
    if ((len == 1 && p[0] >= 0x80) || len > size)
        return 1;

    /*
     * Check for composing characters.  We can handle only the first two, but
     * skip all of them (otherwise the cursor would get stuck).
     */
#ifdef FEAT_ARABIC
    prevlen = 0;
#endif
    while (len < size)
    {
        int     len_next_char;

        if (p[len] < 0x80)
            break;

        /*
         * Next character length should not go beyond size to ensure that
         * UTF_COMPOSINGLIKE(...) does not read beyond size.
         */
        len_next_char = utf_ptr2len_len(p + len, size - len);
        if (len_next_char > size - len)
            break;

        if (!UTF_COMPOSINGLIKE(p + prevlen, p + len))
            break;

        /* Skip over composing char */
#ifdef FEAT_ARABIC
        prevlen = len;
#endif
        len += len_next_char;
    }
    return len;
}

/*
 * Return the number of bytes the UTF-8 encoding of character "c" takes.
 * This does not include composing characters.
 */
    int
utf_char2len(c)
    int         c;
{
    if (c < 0x80)
        return 1;
    if (c < 0x800)
        return 2;
    if (c < 0x10000)
        return 3;
    if (c < 0x200000)
        return 4;
    if (c < 0x4000000)
        return 5;
    return 6;
}

/*
 * Convert Unicode character "c" to UTF-8 string in "buf[]".
 * Returns the number of bytes.
 * This does not include composing characters.
 */
    int
utf_char2bytes(c, buf)
    int         c;
    char_u      *buf;
{
    if (c < 0x80)               /* 7 bits */
    {
        buf[0] = c;
        return 1;
    }
    if (c < 0x800)              /* 11 bits */
    {
        buf[0] = 0xc0 + ((unsigned)c >> 6);
        buf[1] = 0x80 + (c & 0x3f);
        return 2;
    }
    if (c < 0x10000)            /* 16 bits */
    {
        buf[0] = 0xe0 + ((unsigned)c >> 12);
        buf[1] = 0x80 + (((unsigned)c >> 6) & 0x3f);
        buf[2] = 0x80 + (c & 0x3f);
        return 3;
    }
    if (c < 0x200000)           /* 21 bits */
    {
        buf[0] = 0xf0 + ((unsigned)c >> 18);
        buf[1] = 0x80 + (((unsigned)c >> 12) & 0x3f);
        buf[2] = 0x80 + (((unsigned)c >> 6) & 0x3f);
        buf[3] = 0x80 + (c & 0x3f);
        return 4;
    }
    if (c < 0x4000000)          /* 26 bits */
    {
        buf[0] = 0xf8 + ((unsigned)c >> 24);
        buf[1] = 0x80 + (((unsigned)c >> 18) & 0x3f);
        buf[2] = 0x80 + (((unsigned)c >> 12) & 0x3f);
        buf[3] = 0x80 + (((unsigned)c >> 6) & 0x3f);
        buf[4] = 0x80 + (c & 0x3f);
        return 5;
    }
                                /* 31 bits */
    buf[0] = 0xfc + ((unsigned)c >> 30);
    buf[1] = 0x80 + (((unsigned)c >> 24) & 0x3f);
    buf[2] = 0x80 + (((unsigned)c >> 18) & 0x3f);
    buf[3] = 0x80 + (((unsigned)c >> 12) & 0x3f);
    buf[4] = 0x80 + (((unsigned)c >> 6) & 0x3f);
    buf[5] = 0x80 + (c & 0x3f);
    return 6;
}

/*
 * Return TRUE if "c" is a composing UTF-8 character.  This means it will be
 * drawn on top of the preceding character.
 * Based on code from Markus Kuhn.
 */
    int
utf_iscomposing(c)
    int         c;
{
    /* sorted list of non-overlapping intervals */
    static struct interval combining[] =
    {
        {0x0300, 0x034f}, {0x0360, 0x036f}, {0x0483, 0x0486}, {0x0488, 0x0489},
        {0x0591, 0x05a1}, {0x05a3, 0x05b9}, {0x05bb, 0x05bd}, {0x05bf, 0x05bf},
        {0x05c1, 0x05c2}, {0x05c4, 0x05c4}, {0x0610, 0x0615}, {0x064b, 0x0658},
        {0x0670, 0x0670}, {0x06d6, 0x06dc}, {0x06de, 0x06e4}, {0x06e7, 0x06e8},
        {0x06ea, 0x06ed}, {0x0711, 0x0711}, {0x0730, 0x074a}, {0x07a6, 0x07b0},
        {0x0901, 0x0903}, {0x093c, 0x093c}, {0x093e, 0x094d}, {0x0951, 0x0954},
        {0x0962, 0x0963}, {0x0981, 0x0983}, {0x09bc, 0x09bc}, {0x09be, 0x09c4},
        {0x09c7, 0x09c8}, {0x09cb, 0x09cd}, {0x09d7, 0x09d7}, {0x09e2, 0x09e3},
        {0x0a01, 0x0a03}, {0x0a3c, 0x0a3c}, {0x0a3e, 0x0a42}, {0x0a47, 0x0a48},
        {0x0a4b, 0x0a4d}, {0x0a70, 0x0a71}, {0x0a81, 0x0a83}, {0x0abc, 0x0abc},
        {0x0abe, 0x0ac5}, {0x0ac7, 0x0ac9}, {0x0acb, 0x0acd}, {0x0ae2, 0x0ae3},
        {0x0b01, 0x0b03}, {0x0b3c, 0x0b3c}, {0x0b3e, 0x0b43}, {0x0b47, 0x0b48},
        {0x0b4b, 0x0b4d}, {0x0b56, 0x0b57}, {0x0b82, 0x0b82}, {0x0bbe, 0x0bc2},
        {0x0bc6, 0x0bc8}, {0x0bca, 0x0bcd}, {0x0bd7, 0x0bd7}, {0x0c01, 0x0c03},
        {0x0c3e, 0x0c44}, {0x0c46, 0x0c48}, {0x0c4a, 0x0c4d}, {0x0c55, 0x0c56},
        {0x0c82, 0x0c83}, {0x0cbc, 0x0cbc}, {0x0cbe, 0x0cc4}, {0x0cc6, 0x0cc8},
        {0x0cca, 0x0ccd}, {0x0cd5, 0x0cd6}, {0x0d02, 0x0d03}, {0x0d3e, 0x0d43},
        {0x0d46, 0x0d48}, {0x0d4a, 0x0d4d}, {0x0d57, 0x0d57}, {0x0d82, 0x0d83},
        {0x0dca, 0x0dca}, {0x0dcf, 0x0dd4}, {0x0dd6, 0x0dd6}, {0x0dd8, 0x0ddf},
        {0x0df2, 0x0df3}, {0x0e31, 0x0e31}, {0x0e34, 0x0e3a}, {0x0e47, 0x0e4e},
        {0x0eb1, 0x0eb1}, {0x0eb4, 0x0eb9}, {0x0ebb, 0x0ebc}, {0x0ec8, 0x0ecd},
        {0x0f18, 0x0f19}, {0x0f35, 0x0f35}, {0x0f37, 0x0f37}, {0x0f39, 0x0f39},
        {0x0f3e, 0x0f3f}, {0x0f71, 0x0f84}, {0x0f86, 0x0f87}, {0x0f90, 0x0f97},
        {0x0f99, 0x0fbc}, {0x0fc6, 0x0fc6}, {0x102c, 0x1032}, {0x1036, 0x1039},
        {0x1056, 0x1059}, {0x1712, 0x1714}, {0x1732, 0x1734}, {0x1752, 0x1753},
        {0x1772, 0x1773}, {0x17b6, 0x17d3}, {0x17dd, 0x17dd}, {0x180b, 0x180d},
        {0x18a9, 0x18a9}, {0x1920, 0x192b}, {0x1930, 0x193b}, {0x20d0, 0x20ea},
        {0x302a, 0x302f}, {0x3099, 0x309a}, {0xfb1e, 0xfb1e}, {0xfe00, 0xfe0f},
        {0xfe20, 0xfe23},
    };

    return intable(combining, sizeof(combining), c);
}

/*
 * Return TRUE for characters that can be displayed in a normal way.
 * Only for characters of 0x100 and above!
 */
    int
utf_printable(c)
    int         c;
{
#ifdef USE_WCHAR_FUNCTIONS
    /*
     * Assume the iswprint() library function works better than our own stuff.
     */
    return iswprint(c);
#else
    /* Sorted list of non-overlapping intervals.
     * 0xd800-0xdfff is reserved for UTF-16, actually illegal. */
    static struct interval nonprint[] =
    {
        {0x070f, 0x070f}, {0x180b, 0x180e}, {0x200b, 0x200f}, {0x202a, 0x202e},
        {0x206a, 0x206f}, {0xd800, 0xdfff}, {0xfeff, 0xfeff}, {0xfff9, 0xfffb},
        {0xfffe, 0xffff}
    };

    return !intable(nonprint, sizeof(nonprint), c);
#endif
}

/*
 * Get class of a Unicode character.
 * 0: white space
 * 1: punctuation
 * 2 or bigger: some class of word character.
 */
    int
utf_class(c)
    int         c;
{
    /* sorted list of non-overlapping intervals */
    static struct clinterval
    {
        unsigned short first;
        unsigned short last;
        unsigned short class;
    } classes[] =
    {
        {0x037e, 0x037e, 1},            /* Greek question mark */
        {0x0387, 0x0387, 1},            /* Greek ano teleia */
        {0x055a, 0x055f, 1},            /* Armenian punctuation */
        {0x0589, 0x0589, 1},            /* Armenian full stop */
        {0x05be, 0x05be, 1},
        {0x05c0, 0x05c0, 1},
        {0x05c3, 0x05c3, 1},
        {0x05f3, 0x05f4, 1},
        {0x060c, 0x060c, 1},
        {0x061b, 0x061b, 1},
        {0x061f, 0x061f, 1},
        {0x066a, 0x066d, 1},
        {0x06d4, 0x06d4, 1},
        {0x0700, 0x070d, 1},            /* Syriac punctuation */
        {0x0964, 0x0965, 1},
        {0x0970, 0x0970, 1},
        {0x0df4, 0x0df4, 1},
        {0x0e4f, 0x0e4f, 1},
        {0x0e5a, 0x0e5b, 1},
        {0x0f04, 0x0f12, 1},
        {0x0f3a, 0x0f3d, 1},
        {0x0f85, 0x0f85, 1},
        {0x104a, 0x104f, 1},            /* Myanmar punctuation */
        {0x10fb, 0x10fb, 1},            /* Georgian punctuation */
        {0x1361, 0x1368, 1},            /* Ethiopic punctuation */
        {0x166d, 0x166e, 1},            /* Canadian Syl. punctuation */
        {0x1680, 0x1680, 0},
        {0x169b, 0x169c, 1},
        {0x16eb, 0x16ed, 1},
        {0x1735, 0x1736, 1},
        {0x17d4, 0x17dc, 1},            /* Khmer punctuation */
        {0x1800, 0x180a, 1},            /* Mongolian punctuation */
        {0x2000, 0x200b, 0},            /* spaces */
        {0x200c, 0x2027, 1},            /* punctuation and symbols */
        {0x2028, 0x2029, 0},
        {0x202a, 0x202e, 1},            /* punctuation and symbols */
        {0x202f, 0x202f, 0},
        {0x2030, 0x205e, 1},            /* punctuation and symbols */
        {0x205f, 0x205f, 0},
        {0x2060, 0x27ff, 1},            /* punctuation and symbols */
        {0x2070, 0x207f, 0x2070},       /* superscript */
        {0x2080, 0x2094, 0x2080},       /* subscript */
        {0x20a0, 0x27ff, 1},            /* all kinds of symbols */
        {0x2800, 0x28ff, 0x2800},       /* braille */
        {0x2900, 0x2998, 1},            /* arrows, brackets, etc. */
        {0x29d8, 0x29db, 1},
        {0x29fc, 0x29fd, 1},
        {0x3000, 0x3000, 0},            /* ideographic space */
        {0x3001, 0x3020, 1},            /* ideographic punctuation */
        {0x3030, 0x3030, 1},
        {0x303d, 0x303d, 1},
        {0x3040, 0x309f, 0x3040},       /* Hiragana */
        {0x30a0, 0x30ff, 0x30a0},       /* Katakana */
        {0x3300, 0x9fff, 0x4e00},       /* CJK Ideographs */
        {0xac00, 0xd7a3, 0xac00},       /* Hangul Syllables */
        {0xf900, 0xfaff, 0x4e00},       /* CJK Ideographs */
        {0xfd3e, 0xfd3f, 1},
        {0xfe30, 0xfe6b, 1},            /* punctuation forms */
        {0xff00, 0xff0f, 1},            /* half/fullwidth ASCII */
        {0xff1a, 0xff20, 1},            /* half/fullwidth ASCII */
        {0xff3b, 0xff40, 1},            /* half/fullwidth ASCII */
        {0xff5b, 0xff65, 1},            /* half/fullwidth ASCII */
    };
    int bot = 0;
    int top = sizeof(classes) / sizeof(struct clinterval) - 1;
    int mid;

    /* First quick check for Latin1 characters, use 'iskeyword'. */
    if (c < 0x100)
    {
        if (c == ' ' || c == '\t' || c == NUL || c == 0xa0)
            return 0;       /* blank */
        if (vim_iswordc(c))
            return 2;       /* word character */
        return 1;           /* punctuation */
    }

    /* binary search in table */
    while (top >= bot)
    {
        mid = (bot + top) / 2;
        if (classes[mid].last < c)
            bot = mid + 1;
        else if (classes[mid].first > c)
            top = mid - 1;
        else
            return (int)classes[mid].class;
    }

    /* most other characters are "word" characters */
    return 2;
}

/*
 * Code for Unicode case-dependent operations.  Based on notes in
 * http://www.unicode.org/Public/UNIDATA/CaseFolding.txt
 * This code uses simple case folding, not full case folding.
 */

/*
 * The following table is built by foldExtract.pl < CaseFolding.txt .
 * It must be in numeric order, because we use binary search on it.
 * An entry such as {0x41,0x5a,1,32} means that UCS-4 characters in the range
 * from 0x41 to 0x5a inclusive, stepping by 1, are folded by adding 32.
 */

typedef struct
{
    int rangeStart;
    int rangeEnd;
    int step;
    int offset;
} convertStruct;

static convertStruct foldCase[] =
{
        {0x41,0x5a,1,32}, {0xc0,0xd6,1,32}, {0xd8,0xde,1,32},
        {0x100,0x12e,2,1}, {0x130,0x130,-1,-199}, {0x132,0x136,2,1},
        {0x139,0x147,2,1}, {0x14a,0x176,2,1}, {0x178,0x178,-1,-121},
        {0x179,0x17d,2,1}, {0x181,0x181,-1,210}, {0x182,0x184,2,1},
        {0x186,0x186,-1,206}, {0x187,0x187,-1,1}, {0x189,0x18a,1,205},
        {0x18b,0x18b,-1,1}, {0x18e,0x18e,-1,79}, {0x18f,0x18f,-1,202},
        {0x190,0x190,-1,203}, {0x191,0x191,-1,1}, {0x193,0x193,-1,205},
        {0x194,0x194,-1,207}, {0x196,0x196,-1,211}, {0x197,0x197,-1,209},
        {0x198,0x198,-1,1}, {0x19c,0x19c,-1,211}, {0x19d,0x19d,-1,213},
        {0x19f,0x19f,-1,214}, {0x1a0,0x1a4,2,1}, {0x1a6,0x1a6,-1,218},
        {0x1a7,0x1a7,-1,1}, {0x1a9,0x1a9,-1,218}, {0x1ac,0x1ac,-1,1},
        {0x1ae,0x1ae,-1,218}, {0x1af,0x1af,-1,1}, {0x1b1,0x1b2,1,217},
        {0x1b3,0x1b5,2,1}, {0x1b7,0x1b7,-1,219}, {0x1b8,0x1bc,4,1},
        {0x1c4,0x1c4,-1,2}, {0x1c5,0x1c5,-1,1}, {0x1c7,0x1c7,-1,2},
        {0x1c8,0x1c8,-1,1}, {0x1ca,0x1ca,-1,2}, {0x1cb,0x1db,2,1},
        {0x1de,0x1ee,2,1}, {0x1f1,0x1f1,-1,2}, {0x1f2,0x1f4,2,1},
        {0x1f6,0x1f6,-1,-97}, {0x1f7,0x1f7,-1,-56}, {0x1f8,0x21e,2,1},
        {0x220,0x220,-1,-130}, {0x222,0x232,2,1}, {0x386,0x386,-1,38},
        {0x388,0x38a,1,37}, {0x38c,0x38c,-1,64}, {0x38e,0x38f,1,63},
        {0x391,0x3a1,1,32}, {0x3a3,0x3ab,1,32}, {0x3d8,0x3ee,2,1},
        {0x3f4,0x3f4,-1,-60}, {0x3f7,0x3f7,-1,1}, {0x3f9,0x3f9,-1,-7},
        {0x3fa,0x3fa,-1,1}, {0x400,0x40f,1,80}, {0x410,0x42f,1,32},
        {0x460,0x480,2,1}, {0x48a,0x4be,2,1}, {0x4c1,0x4cd,2,1},
        {0x4d0,0x4f4,2,1}, {0x4f8,0x500,8,1}, {0x502,0x50e,2,1},
        {0x531,0x556,1,48}, {0x1e00,0x1e94,2,1}, {0x1ea0,0x1ef8,2,1},
        {0x1f08,0x1f0f,1,-8}, {0x1f18,0x1f1d,1,-8}, {0x1f28,0x1f2f,1,-8},
        {0x1f38,0x1f3f,1,-8}, {0x1f48,0x1f4d,1,-8}, {0x1f59,0x1f5f,2,-8},
        {0x1f68,0x1f6f,1,-8}, {0x1f88,0x1f8f,1,-8}, {0x1f98,0x1f9f,1,-8},
        {0x1fa8,0x1faf,1,-8}, {0x1fb8,0x1fb9,1,-8}, {0x1fba,0x1fbb,1,-74},
        {0x1fbc,0x1fbc,-1,-9}, {0x1fc8,0x1fcb,1,-86}, {0x1fcc,0x1fcc,-1,-9},
        {0x1fd8,0x1fd9,1,-8}, {0x1fda,0x1fdb,1,-100}, {0x1fe8,0x1fe9,1,-8},
        {0x1fea,0x1feb,1,-112}, {0x1fec,0x1fec,-1,-7}, {0x1ff8,0x1ff9,1,-128},
        {0x1ffa,0x1ffb,1,-126}, {0x1ffc,0x1ffc,-1,-9}, {0x2126,0x2126,-1,-7517},
        {0x212a,0x212a,-1,-8383}, {0x212b,0x212b,-1,-8262},
        {0x2160,0x216f,1,16}, {0x24b6,0x24cf,1,26}, {0xff21,0xff3a,1,32},
        {0x10400,0x10427,1,40}
};

static int utf_convert(int a, convertStruct table[], int tableSize);

/*
 * Generic conversion function for case operations.
 * Return the converted equivalent of "a", which is a UCS-4 character.  Use
 * the given conversion "table".  Uses binary search on "table".
 */
    static int
utf_convert(a, table, tableSize)
    int                 a;
    convertStruct       table[];
    int                 tableSize;
{
    int start, mid, end; /* indices into table */

    start = 0;
    end = tableSize / sizeof(convertStruct);
    while (start < end)
    {
        /* need to search further */
        mid = (end + start) /2;
        if (table[mid].rangeEnd < a)
            start = mid + 1;
        else
            end = mid;
    }
    if (table[start].rangeStart <= a && a <= table[start].rangeEnd
            && (a - table[start].rangeStart) % table[start].step == 0)
        return (a + table[start].offset);
    else
        return a;
}

/*
 * Return the folded-case equivalent of "a", which is a UCS-4 character.  Uses
 * simple case folding.
 */
    int
utf_fold(a)
    int         a;
{
    return utf_convert(a, foldCase, sizeof(foldCase));
}

/*
 * The following tables are built by upperLowerExtract.pl < UnicodeData.txt .
 * They must be in numeric order, because we use binary search on them.
 * An entry such as {0x41,0x5a,1,32} means that UCS-4 characters in the range
 * from 0x41 to 0x5a inclusive, stepping by 1, are switched to lower (for
 * example) by adding 32.
 */
static convertStruct toLower[] =
{
        {0x41,0x5a,1,32}, {0xc0,0xd6,1,32}, {0xd8,0xde,1,32},
        {0x100,0x12e,2,1}, {0x130,0x130,-1,-199}, {0x132,0x136,2,1},
        {0x139,0x147,2,1}, {0x14a,0x176,2,1}, {0x178,0x178,-1,-121},
        {0x179,0x17d,2,1}, {0x181,0x181,-1,210}, {0x182,0x184,2,1},
        {0x186,0x186,-1,206}, {0x187,0x187,-1,1}, {0x189,0x18a,1,205},
        {0x18b,0x18b,-1,1}, {0x18e,0x18e,-1,79}, {0x18f,0x18f,-1,202},
        {0x190,0x190,-1,203}, {0x191,0x191,-1,1}, {0x193,0x193,-1,205},
        {0x194,0x194,-1,207}, {0x196,0x196,-1,211}, {0x197,0x197,-1,209},
        {0x198,0x198,-1,1}, {0x19c,0x19c,-1,211}, {0x19d,0x19d,-1,213},
        {0x19f,0x19f,-1,214}, {0x1a0,0x1a4,2,1}, {0x1a6,0x1a6,-1,218},
        {0x1a7,0x1a7,-1,1}, {0x1a9,0x1a9,-1,218}, {0x1ac,0x1ac,-1,1},
        {0x1ae,0x1ae,-1,218}, {0x1af,0x1af,-1,1}, {0x1b1,0x1b2,1,217},
        {0x1b3,0x1b5,2,1}, {0x1b7,0x1b7,-1,219}, {0x1b8,0x1bc,4,1},
        {0x1c4,0x1ca,3,2}, {0x1cd,0x1db,2,1}, {0x1de,0x1ee,2,1},
        {0x1f1,0x1f1,-1,2}, {0x1f4,0x1f4,-1,1}, {0x1f6,0x1f6,-1,-97},
        {0x1f7,0x1f7,-1,-56}, {0x1f8,0x21e,2,1}, {0x220,0x220,-1,-130},
        {0x222,0x232,2,1}, {0x386,0x386,-1,38}, {0x388,0x38a,1,37},
        {0x38c,0x38c,-1,64}, {0x38e,0x38f,1,63}, {0x391,0x3a1,1,32},
        {0x3a3,0x3ab,1,32}, {0x3d8,0x3ee,2,1}, {0x3f4,0x3f4,-1,-60},
        {0x3f7,0x3f7,-1,1}, {0x3f9,0x3f9,-1,-7}, {0x3fa,0x3fa,-1,1},
        {0x400,0x40f,1,80}, {0x410,0x42f,1,32}, {0x460,0x480,2,1},
        {0x48a,0x4be,2,1}, {0x4c1,0x4cd,2,1}, {0x4d0,0x4f4,2,1},
        {0x4f8,0x500,8,1}, {0x502,0x50e,2,1}, {0x531,0x556,1,48},
        {0x1e00,0x1e94,2,1}, {0x1ea0,0x1ef8,2,1}, {0x1f08,0x1f0f,1,-8},
        {0x1f18,0x1f1d,1,-8}, {0x1f28,0x1f2f,1,-8}, {0x1f38,0x1f3f,1,-8},
        {0x1f48,0x1f4d,1,-8}, {0x1f59,0x1f5f,2,-8}, {0x1f68,0x1f6f,1,-8},
        {0x1fb8,0x1fb9,1,-8}, {0x1fba,0x1fbb,1,-74}, {0x1fc8,0x1fcb,1,-86},
        {0x1fd8,0x1fd9,1,-8}, {0x1fda,0x1fdb,1,-100}, {0x1fe8,0x1fe9,1,-8},
        {0x1fea,0x1feb,1,-112}, {0x1fec,0x1fec,-1,-7}, {0x1ff8,0x1ff9,1,-128},
        {0x1ffa,0x1ffb,1,-126}, {0x2126,0x2126,-1,-7517}, {0x212a,0x212a,-1,-8383},
        {0x212b,0x212b,-1,-8262}, {0xff21,0xff3a,1,32}, {0x10400,0x10427,1,40}
};

static convertStruct toUpper[] =
{
        {0x61,0x7a,1,-32}, {0xb5,0xb5,-1,743}, {0xe0,0xf6,1,-32},
        {0xf8,0xfe,1,-32}, {0xff,0xff,-1,121}, {0x101,0x12f,2,-1},
        {0x131,0x131,-1,-232}, {0x133,0x137,2,-1}, {0x13a,0x148,2,-1},
        {0x14b,0x177,2,-1}, {0x17a,0x17e,2,-1}, {0x17f,0x17f,-1,-300},
        {0x183,0x185,2,-1}, {0x188,0x18c,4,-1}, {0x192,0x192,-1,-1},
        {0x195,0x195,-1,97}, {0x199,0x199,-1,-1}, {0x19e,0x19e,-1,130},
        {0x1a1,0x1a5,2,-1}, {0x1a8,0x1ad,5,-1}, {0x1b0,0x1b4,4,-1},
        {0x1b6,0x1b9,3,-1}, {0x1bd,0x1bd,-1,-1}, {0x1bf,0x1bf,-1,56},
        {0x1c5,0x1c6,1,-1}, {0x1c8,0x1c9,1,-1}, {0x1cb,0x1cc,1,-1},
        {0x1ce,0x1dc,2,-1}, {0x1dd,0x1dd,-1,-79}, {0x1df,0x1ef,2,-1},
        {0x1f2,0x1f3,1,-1}, {0x1f5,0x1f9,4,-1}, {0x1fb,0x21f,2,-1},
        {0x223,0x233,2,-1}, {0x253,0x253,-1,-210}, {0x254,0x254,-1,-206},
        {0x256,0x257,1,-205}, {0x259,0x259,-1,-202}, {0x25b,0x25b,-1,-203},
        {0x260,0x260,-1,-205}, {0x263,0x263,-1,-207}, {0x268,0x268,-1,-209},
        {0x269,0x26f,6,-211}, {0x272,0x272,-1,-213}, {0x275,0x275,-1,-214},
        {0x280,0x283,3,-218}, {0x288,0x288,-1,-218}, {0x28a,0x28b,1,-217},
        {0x292,0x292,-1,-219}, {0x3ac,0x3ac,-1,-38}, {0x3ad,0x3af,1,-37},
        {0x3b1,0x3c1,1,-32}, {0x3c2,0x3c2,-1,-31}, {0x3c3,0x3cb,1,-32},
        {0x3cc,0x3cc,-1,-64}, {0x3cd,0x3ce,1,-63}, {0x3d0,0x3d0,-1,-62},
        {0x3d1,0x3d1,-1,-57}, {0x3d5,0x3d5,-1,-47}, {0x3d6,0x3d6,-1,-54},
        {0x3d9,0x3ef,2,-1}, {0x3f0,0x3f0,-1,-86}, {0x3f1,0x3f1,-1,-80},
        {0x3f2,0x3f2,-1,7}, {0x3f5,0x3f5,-1,-96}, {0x3f8,0x3fb,3,-1},
        {0x430,0x44f,1,-32}, {0x450,0x45f,1,-80}, {0x461,0x481,2,-1},
        {0x48b,0x4bf,2,-1}, {0x4c2,0x4ce,2,-1}, {0x4d1,0x4f5,2,-1},
        {0x4f9,0x501,8,-1}, {0x503,0x50f,2,-1}, {0x561,0x586,1,-48},
        {0x1e01,0x1e95,2,-1}, {0x1e9b,0x1e9b,-1,-59}, {0x1ea1,0x1ef9,2,-1},
        {0x1f00,0x1f07,1,8}, {0x1f10,0x1f15,1,8}, {0x1f20,0x1f27,1,8},
        {0x1f30,0x1f37,1,8}, {0x1f40,0x1f45,1,8}, {0x1f51,0x1f57,2,8},
        {0x1f60,0x1f67,1,8}, {0x1f70,0x1f71,1,74}, {0x1f72,0x1f75,1,86},
        {0x1f76,0x1f77,1,100}, {0x1f78,0x1f79,1,128}, {0x1f7a,0x1f7b,1,112},
        {0x1f7c,0x1f7d,1,126}, {0x1f80,0x1f87,1,8}, {0x1f90,0x1f97,1,8},
        {0x1fa0,0x1fa7,1,8}, {0x1fb0,0x1fb1,1,8}, {0x1fb3,0x1fb3,-1,9},
        {0x1fbe,0x1fbe,-1,-7205}, {0x1fc3,0x1fc3,-1,9}, {0x1fd0,0x1fd1,1,8},
        {0x1fe0,0x1fe1,1,8}, {0x1fe5,0x1fe5,-1,7}, {0x1ff3,0x1ff3,-1,9},
        {0xff41,0xff5a,1,-32}, {0x10428,0x1044f,1,-40}
};

/*
 * Return the upper-case equivalent of "a", which is a UCS-4 character.  Use
 * simple case folding.
 */
    int
utf_toupper(a)
    int         a;
{
    /* If 'casemap' contains "keepascii" use ASCII style toupper(). */
    if (a < 128 && (cmp_flags & CMP_KEEPASCII))
        return TOUPPER_ASC(a);

#if defined(HAVE_TOWUPPER) && defined(__STDC_ISO_10646__)
    /* If towupper() is available and handles Unicode, use it. */
    if (!(cmp_flags & CMP_INTERNAL))
        return towupper(a);
#endif

    /* For characters below 128 use locale sensitive toupper(). */
    if (a < 128)
        return TOUPPER_LOC(a);

    /* For any other characters use the above mapping table. */
    return utf_convert(a, toUpper, sizeof(toUpper));
}

    int
utf_islower(a)
    int         a;
{
    return (utf_toupper(a) != a);
}

/*
 * Return the lower-case equivalent of "a", which is a UCS-4 character.  Use
 * simple case folding.
 */
    int
utf_tolower(a)
    int         a;
{
    /* If 'casemap' contains "keepascii" use ASCII style tolower(). */
    if (a < 128 && (cmp_flags & CMP_KEEPASCII))
        return TOLOWER_ASC(a);

#if defined(HAVE_TOWLOWER) && defined(__STDC_ISO_10646__)
    /* If towlower() is available and handles Unicode, use it. */
    if (!(cmp_flags & CMP_INTERNAL))
        return towlower(a);
#endif

    /* For characters below 128 use locale sensitive tolower(). */
    if (a < 128)
        return TOLOWER_LOC(a);

    /* For any other characters use the above mapping table. */
    return utf_convert(a, toLower, sizeof(toLower));
}

    int
utf_isupper(a)
    int         a;
{
    return (utf_tolower(a) != a);
}

/*
 * Version of strnicmp() that handles multi-byte characters.
 * Needed for Big5, Sjift-JIS and UTF-8 encoding.  Other DBCS encodings can
 * probably use strnicmp(), because there are no ASCII characters in the
 * second byte.
 * Returns zero if s1 and s2 are equal (ignoring case), the difference between
 * two characters otherwise.
 */
    int
mb_strnicmp(s1, s2, nn)
    char_u      *s1, *s2;
    size_t      nn;
{
    int         i, j, l;
    int         cdiff;
    int         incomplete = FALSE;
    int         n = (int)nn;

    for (i = 0; i < n; i += l)
    {
        if (s1[i] == NUL && s2[i] == NUL)   /* both strings end */
            return 0;
        if (enc_utf8)
        {
            l = utf_byte2len(s1[i]);
            if (l > n - i)
            {
                l = n - i;                  /* incomplete character */
                incomplete = TRUE;
            }
            /* Check directly first, it's faster. */
            for (j = 0; j < l; ++j)
            {
                if (s1[i + j] != s2[i + j])
                    break;
                if (s1[i + j] == 0)
                    /* Both stings have the same bytes but are incomplete or
                     * have illegal bytes, accept them as equal. */
                    l = j;
            }
            if (j < l)
            {
                /* If one of the two characters is incomplete return -1. */
                if (incomplete || i + utf_byte2len(s2[i]) > n)
                    return -1;
                cdiff = utf_fold(utf_ptr2char(s1 + i))
                                             - utf_fold(utf_ptr2char(s2 + i));
                if (cdiff != 0)
                    return cdiff;
            }
        }
        else
        {
            l = (*mb_ptr2len)(s1 + i);
            if (l <= 1)
            {
                /* Single byte: first check normally, then with ignore case. */
                if (s1[i] != s2[i])
                {
                    cdiff = MB_TOLOWER(s1[i]) - MB_TOLOWER(s2[i]);
                    if (cdiff != 0)
                        return cdiff;
                }
            }
            else
            {
                /* For non-Unicode multi-byte don't ignore case. */
                if (l > n - i)
                    l = n - i;
                cdiff = STRNCMP(s1 + i, s2 + i, l);
                if (cdiff != 0)
                    return cdiff;
            }
        }
    }
    return 0;
}

/*
 * "g8": show bytes of the UTF-8 char under the cursor.  Doesn't matter what
 * 'encoding' has been set to.
 */
    void
show_utf8()
{
    int         len;
    int         rlen = 0;
    char_u      *line;
    int         clen;
    int         i;

    /* Get the byte length of the char under the cursor, including composing
     * characters. */
    line = ml_get_cursor();
    len = utfc_ptr2len(line);
    if (len == 0)
    {
        MSG("NUL");
        return;
    }

    clen = 0;
    for (i = 0; i < len; ++i)
    {
        if (clen == 0)
        {
            /* start of (composing) character, get its length */
            if (i > 0)
            {
                STRCPY(IObuff + rlen, "+ ");
                rlen += 2;
            }
            clen = utf_ptr2len(line + i);
        }
        sprintf((char *)IObuff + rlen, "%02x ", line[i]);
        --clen;
        rlen += (int)STRLEN(IObuff + rlen);
        if (rlen > IOSIZE - 20)
            break;
    }

    msg(IObuff);
}

/*
 * mb_head_off() function pointer.
 * Return offset from "p" to the first byte of the character it points into.
 * If "p" points to the NUL at the end of the string return 0.
 * Returns 0 when already at the first byte of a character.
 */
    int
latin_head_off(base, p)
    char_u      *base UNUSED;
    char_u      *p UNUSED;
{
    return 0;
}

    int
dbcs_head_off(base, p)
    char_u      *base;
    char_u      *p;
{
    char_u      *q;

    /* It can't be a trailing byte when not using DBCS, at the start of the
     * string or the previous byte can't start a double-byte. */
    if (p <= base || MB_BYTE2LEN(p[-1]) == 1 || *p == NUL)
        return 0;

    /* This is slow: need to start at the base and go forward until the
     * byte we are looking for.  Return 1 when we went past it, 0 otherwise. */
    q = base;
    while (q < p)
        q += dbcs_ptr2len(q);
    return (q == p) ? 0 : 1;
}

/*
 * Special version of dbcs_head_off() that works for ScreenLines[], where
 * single-width DBCS_JPNU characters are stored separately.
 */
    int
dbcs_screen_head_off(base, p)
    char_u      *base;
    char_u      *p;
{
    char_u      *q;

    /* It can't be a trailing byte when not using DBCS, at the start of the
     * string or the previous byte can't start a double-byte.
     * For euc-jp an 0x8e byte in the previous cell always means we have a
     * lead byte in the current cell. */
    if (p <= base
            || (enc_dbcs == DBCS_JPNU && p[-1] == 0x8e)
            || MB_BYTE2LEN(p[-1]) == 1
            || *p == NUL)
        return 0;

    /* This is slow: need to start at the base and go forward until the
     * byte we are looking for.  Return 1 when we went past it, 0 otherwise.
     * For DBCS_JPNU look out for 0x8e, which means the second byte is not
     * stored as the next byte. */
    q = base;
    while (q < p)
    {
        if (enc_dbcs == DBCS_JPNU && *q == 0x8e)
            ++q;
        else
            q += dbcs_ptr2len(q);
    }
    return (q == p) ? 0 : 1;
}

    int
utf_head_off(base, p)
    char_u      *base;
    char_u      *p;
{
    char_u      *q;
    char_u      *s;
    int         c;
    int         len;
#ifdef FEAT_ARABIC
    char_u      *j;
#endif

    if (*p < 0x80)              /* be quick for ASCII */
        return 0;

    /* Skip backwards over trailing bytes: 10xx.xxxx
     * Skip backwards again if on a composing char. */
    for (q = p; ; --q)
    {
        /* Move s to the last byte of this char. */
        for (s = q; (s[1] & 0xc0) == 0x80; ++s)
            ;
        /* Move q to the first byte of this char. */
        while (q > base && (*q & 0xc0) == 0x80)
            --q;
        /* Check for illegal sequence. Do allow an illegal byte after where we
         * started. */
        len = utf8len_tab[*q];
        if (len != (int)(s - q + 1) && len != (int)(p - q + 1))
            return 0;

        if (q <= base)
            break;

        c = utf_ptr2char(q);
        if (utf_iscomposing(c))
            continue;

#ifdef FEAT_ARABIC
        if (arabic_maycombine(c))
        {
            /* Advance to get a sneak-peak at the next char */
            j = q;
            --j;
            /* Move j to the first byte of this char. */
            while (j > base && (*j & 0xc0) == 0x80)
                --j;
            if (arabic_combine(utf_ptr2char(j), c))
                continue;
        }
#endif
        break;
    }

    return (int)(p - q);
}

/*
 * Copy a character from "*fp" to "*tp" and advance the pointers.
 */
    void
mb_copy_char(fp, tp)
    char_u      **fp;
    char_u      **tp;
{
    int     l = (*mb_ptr2len)(*fp);

    mch_memmove(*tp, *fp, (size_t)l);
    *tp += l;
    *fp += l;
}

/*
 * Return the offset from "p" to the first byte of a character.  When "p" is
 * at the start of a character 0 is returned, otherwise the offset to the next
 * character.  Can start anywhere in a stream of bytes.
 */
    int
mb_off_next(base, p)
    char_u      *base;
    char_u      *p;
{
    int         i;
    int         j;

    if (enc_utf8)
    {
        if (*p < 0x80)          /* be quick for ASCII */
            return 0;

        /* Find the next character that isn't 10xx.xxxx */
        for (i = 0; (p[i] & 0xc0) == 0x80; ++i)
            ;
        if (i > 0)
        {
            /* Check for illegal sequence. */
            for (j = 0; p - j > base; ++j)
                if ((p[-j] & 0xc0) != 0x80)
                    break;
            if (utf8len_tab[p[-j]] != i + j)
                return 0;
        }
        return i;
    }

    /* Only need to check if we're on a trail byte, it doesn't matter if we
     * want the offset to the next or current character. */
    return (*mb_head_off)(base, p);
}

/*
 * Return the offset from "p" to the last byte of the character it points
 * into.  Can start anywhere in a stream of bytes.
 */
    int
mb_tail_off(base, p)
    char_u      *base;
    char_u      *p;
{
    int         i;
    int         j;

    if (*p == NUL)
        return 0;

    if (enc_utf8)
    {
        /* Find the last character that is 10xx.xxxx */
        for (i = 0; (p[i + 1] & 0xc0) == 0x80; ++i)
            ;
        /* Check for illegal sequence. */
        for (j = 0; p - j > base; ++j)
            if ((p[-j] & 0xc0) != 0x80)
                break;
        if (utf8len_tab[p[-j]] != i + j + 1)
            return 0;
        return i;
    }

    /* It can't be the first byte if a double-byte when not using DBCS, at the
     * end of the string or the byte can't start a double-byte. */
    if (enc_dbcs == 0 || p[1] == NUL || MB_BYTE2LEN(*p) == 1)
        return 0;

    /* Return 1 when on the lead byte, 0 when on the tail byte. */
    return 1 - dbcs_head_off(base, p);
}

/*
 * Find the next illegal byte sequence.
 */
    void
utf_find_illegal()
{
    pos_T       pos = curwin->w_cursor;
    char_u      *p;
    int         len;
    vimconv_T   vimconv;
    char_u      *tofree = NULL;

    vimconv.vc_type = CONV_NONE;
    if (enc_utf8 && (enc_canon_props(curbuf->b_p_fenc) & ENC_8BIT))
    {
        /* 'encoding' is "utf-8" but we are editing a 8-bit encoded file,
         * possibly a utf-8 file with illegal bytes.  Setup for conversion
         * from utf-8 to 'fileencoding'. */
        convert_setup(&vimconv, p_enc, curbuf->b_p_fenc);
    }

#ifdef FEAT_VIRTUALEDIT
    curwin->w_cursor.coladd = 0;
#endif
    for (;;)
    {
        p = ml_get_cursor();
        if (vimconv.vc_type != CONV_NONE)
        {
            vim_free(tofree);
            tofree = string_convert(&vimconv, p, NULL);
            if (tofree == NULL)
                break;
            p = tofree;
        }

        while (*p != NUL)
        {
            /* Illegal means that there are not enough trail bytes (checked by
             * utf_ptr2len()) or too many of them (overlong sequence). */
            len = utf_ptr2len(p);
            if (*p >= 0x80 && (len == 1
                                     || utf_char2len(utf_ptr2char(p)) != len))
            {
                if (vimconv.vc_type == CONV_NONE)
                    curwin->w_cursor.col += (colnr_T)(p - ml_get_cursor());
                else
                {
                    int     l;

                    len = (int)(p - tofree);
                    for (p = ml_get_cursor(); *p != NUL && len-- > 0; p += l)
                    {
                        l = utf_ptr2len(p);
                        curwin->w_cursor.col += l;
                    }
                }
                goto theend;
            }
            p += len;
        }
        if (curwin->w_cursor.lnum == curbuf->b_ml.ml_line_count)
            break;
        ++curwin->w_cursor.lnum;
        curwin->w_cursor.col = 0;
    }

    /* didn't find it: don't move and beep */
    curwin->w_cursor = pos;
    beep_flush();

theend:
    vim_free(tofree);
    convert_setup(&vimconv, NULL, NULL);
}

#if defined(HAVE_GTK2) || defined(PROTO)
/*
 * Return TRUE if string "s" is a valid utf-8 string.
 * When "end" is NULL stop at the first NUL.
 * When "end" is positive stop there.
 */
    int
utf_valid_string(s, end)
    char_u      *s;
    char_u      *end;
{
    int         l;
    char_u      *p = s;

    while (end == NULL ? *p != NUL : p < end)
    {
        l = utf8len_tab_zero[*p];
        if (l == 0)
            return FALSE;       /* invalid lead byte */
        if (end != NULL && p + l > end)
            return FALSE;       /* incomplete byte sequence */
        ++p;
        while (--l > 0)
            if ((*p++ & 0xc0) != 0x80)
                return FALSE;   /* invalid trail byte */
    }
    return TRUE;
}
#endif

#if defined(FEAT_GUI) || defined(PROTO)
/*
 * Special version of mb_tail_off() for use in ScreenLines[].
 */
    int
dbcs_screen_tail_off(base, p)
    char_u      *base;
    char_u      *p;
{
    /* It can't be the first byte if a double-byte when not using DBCS, at the
     * end of the string or the byte can't start a double-byte.
     * For euc-jp an 0x8e byte always means we have a lead byte in the current
     * cell. */
    if (*p == NUL || p[1] == NUL
            || (enc_dbcs == DBCS_JPNU && *p == 0x8e)
            || MB_BYTE2LEN(*p) == 1)
        return 0;

    /* Return 1 when on the lead byte, 0 when on the tail byte. */
    return 1 - dbcs_screen_head_off(base, p);
}
#endif

/*
 * If the cursor moves on an trail byte, set the cursor on the lead byte.
 * Thus it moves left if necessary.
 * Return TRUE when the cursor was adjusted.
 */
    void
mb_adjust_cursor()
{
    mb_adjustpos(&curwin->w_cursor);
}

/*
 * Adjust position "*lp" to point to the first byte of a multi-byte character.
 * If it points to a tail byte it's moved backwards to the head byte.
 */
    void
mb_adjustpos(lp)
    pos_T       *lp;
{
    char_u      *p;

    if (lp->col > 0
#ifdef FEAT_VIRTUALEDIT
            || lp->coladd > 1
#endif
            )
    {
        p = ml_get(lp->lnum);
        lp->col -= (*mb_head_off)(p, p + lp->col);
#ifdef FEAT_VIRTUALEDIT
        /* Reset "coladd" when the cursor would be on the right half of a
         * double-wide character. */
        if (lp->coladd == 1
                && p[lp->col] != TAB
                && vim_isprintc((*mb_ptr2char)(p + lp->col))
                && ptr2cells(p + lp->col) > 1)
            lp->coladd = 0;
#endif
    }
}

/*
 * Return a pointer to the character before "*p", if there is one.
 */
    char_u *
mb_prevptr(line, p)
    char_u *line;       /* start of the string */
    char_u *p;
{
    if (p > line)
        mb_ptr_back(line, p);
    return p;
}

/*
 * Return the character length of "str".  Each multi-byte character (with
 * following composing characters) counts as one.
 */
    int
mb_charlen(str)
    char_u      *str;
{
    char_u      *p = str;
    int         count;

    if (p == NULL)
        return 0;

    for (count = 0; *p != NUL; count++)
        p += (*mb_ptr2len)(p);

    return count;
}

#if defined(FEAT_SPELL) || defined(PROTO)
/*
 * Like mb_charlen() but for a string with specified length.
 */
    int
mb_charlen_len(str, len)
    char_u      *str;
    int         len;
{
    char_u      *p = str;
    int         count;

    for (count = 0; *p != NUL && p < str + len; count++)
        p += (*mb_ptr2len)(p);

    return count;
}
#endif

/*
 * Try to un-escape a multi-byte character.
 * Used for the "to" and "from" part of a mapping.
 * Return the un-escaped string if it is a multi-byte character, and advance
 * "pp" to just after the bytes that formed it.
 * Return NULL if no multi-byte char was found.
 */
    char_u *
mb_unescape(pp)
    char_u **pp;
{
    static char_u       buf[MB_MAXBYTES + 1];
    int                 n, m = 0;
    char_u              *str = *pp;

    /* Must translate K_SPECIAL KS_SPECIAL KE_FILLER to K_SPECIAL and CSI
     * KS_EXTRA KE_CSI to CSI. */
    for (n = 0; str[n] != NUL && m <= MB_MAXBYTES; ++n)
    {
        if (str[n] == K_SPECIAL
                && str[n + 1] == KS_SPECIAL
                && str[n + 2] == KE_FILLER)
        {
            buf[m++] = K_SPECIAL;
            n += 2;
        }
        else if ((str[n] == K_SPECIAL
# ifdef FEAT_GUI
                    || str[n] == CSI
# endif
                 )
                && str[n + 1] == KS_EXTRA
                && str[n + 2] == (int)KE_CSI)
        {
            buf[m++] = CSI;
            n += 2;
        }
        else if (str[n] == K_SPECIAL
# ifdef FEAT_GUI
                || str[n] == CSI
# endif
                )
            break;              /* a special key can't be a multibyte char */
        else
            buf[m++] = str[n];
        buf[m] = NUL;

        /* Return a multi-byte character if it's found.  An illegal sequence
         * will result in a 1 here. */
        if ((*mb_ptr2len)(buf) > 1)
        {
            *pp = str + n + 1;
            return buf;
        }
    }
    return NULL;
}

/*
 * Return TRUE if the character at "row"/"col" on the screen is the left side
 * of a double-width character.
 * Caller must make sure "row" and "col" are not invalid!
 */
    int
mb_lefthalve(row, col)
    int     row;
    int     col;
{
#ifdef FEAT_HANGULIN
    if (composing_hangul)
        return TRUE;
#endif
    return (*mb_off2cells)(LineOffset[row] + col,
                                        LineOffset[row] + screen_Columns) > 1;
}

/*
 * Correct a position on the screen, if it's the right half of a double-wide
 * char move it to the left half.  Returns the corrected column.
 */
    int
mb_fix_col(col, row)
    int         col;
    int         row;
{
    col = check_col(col);
    row = check_row(row);
    if (has_mbyte && ScreenLines != NULL && col > 0
            && ((enc_dbcs
                    && ScreenLines[LineOffset[row] + col] != NUL
                    && dbcs_screen_head_off(ScreenLines + LineOffset[row],
                                         ScreenLines + LineOffset[row] + col))
                || (enc_utf8 && ScreenLines[LineOffset[row] + col] == 0)))
        return col - 1;
    return col;
}
#endif

#if defined(FEAT_MBYTE) || defined(FEAT_POSTSCRIPT) || defined(PROTO)
static int enc_alias_search __ARGS((char_u *name));

/*
 * Skip the Vim specific head of a 'encoding' name.
 */
    char_u *
enc_skip(p)
    char_u      *p;
{
    if (STRNCMP(p, "2byte-", 6) == 0)
        return p + 6;
    if (STRNCMP(p, "8bit-", 5) == 0)
        return p + 5;
    return p;
}

/*
 * Find the canonical name for encoding "enc".
 * When the name isn't recognized, returns "enc" itself, but with all lower
 * case characters and '_' replaced with '-'.
 * Returns an allocated string.  NULL for out-of-memory.
 */
    char_u *
enc_canonize(enc)
    char_u      *enc;
{
    char_u      *r;
    char_u      *p, *s;
    int         i;

# ifdef FEAT_MBYTE
    if (STRCMP(enc, "default") == 0)
    {
        /* Use the default encoding as it's found by set_init_1(). */
        r = get_encoding_default();
        if (r == NULL)
            r = (char_u *)"latin1";
        return vim_strsave(r);
    }
# endif

    /* copy "enc" to allocated memory, with room for two '-' */
    r = alloc((unsigned)(STRLEN(enc) + 3));
    if (r != NULL)
    {
        /* Make it all lower case and replace '_' with '-'. */
        p = r;
        for (s = enc; *s != NUL; ++s)
        {
            if (*s == '_')
                *p++ = '-';
            else
                *p++ = TOLOWER_ASC(*s);
        }
        *p = NUL;

        /* Skip "2byte-" and "8bit-". */
        p = enc_skip(r);

        /* Change "microsoft-cp" to "cp".  Used in some spell files. */
        if (STRNCMP(p, "microsoft-cp", 12) == 0)
            STRMOVE(p, p + 10);

        /* "iso8859" -> "iso-8859" */
        if (STRNCMP(p, "iso8859", 7) == 0)
        {
            STRMOVE(p + 4, p + 3);
            p[3] = '-';
        }

        /* "iso-8859n" -> "iso-8859-n" */
        if (STRNCMP(p, "iso-8859", 8) == 0 && p[8] != '-')
        {
            STRMOVE(p + 9, p + 8);
            p[8] = '-';
        }

        /* "latin-N" -> "latinN" */
        if (STRNCMP(p, "latin-", 6) == 0)
            STRMOVE(p + 5, p + 6);

        if (enc_canon_search(p) >= 0)
        {
            /* canonical name can be used unmodified */
            if (p != r)
                STRMOVE(r, p);
        }
        else if ((i = enc_alias_search(p)) >= 0)
        {
            /* alias recognized, get canonical name */
            vim_free(r);
            r = vim_strsave((char_u *)enc_canon_table[i].name);
        }
    }
    return r;
}

/*
 * Search for an encoding alias of "name".
 * Returns -1 when not found.
 */
    static int
enc_alias_search(name)
    char_u      *name;
{
    int         i;

    for (i = 0; enc_alias_table[i].name != NULL; ++i)
        if (STRCMP(name, enc_alias_table[i].name) == 0)
            return enc_alias_table[i].canon;
    return -1;
}
#endif

#if defined(FEAT_MBYTE) || defined(PROTO)

#ifdef HAVE_LANGINFO_H
# include <langinfo.h>
#endif

/*
 * Get the canonicalized encoding of the current locale.
 * Returns an allocated string when successful, NULL when not.
 */
    char_u *
enc_locale()
{
#ifndef WIN3264
    char        *s;
    char        *p;
    int         i;
#endif
    char        buf[50];
#ifdef WIN3264
    long        acp = GetACP();

    if (acp == 1200)
        STRCPY(buf, "ucs-2le");
    else if (acp == 1252)           /* cp1252 is used as latin1 */
        STRCPY(buf, "latin1");
    else
        sprintf(buf, "cp%ld", acp);
#else
# ifdef HAVE_NL_LANGINFO_CODESET
    if ((s = nl_langinfo(CODESET)) == NULL || *s == NUL)
# endif
#  if defined(HAVE_LOCALE_H) || defined(X_LOCALE)
        if ((s = setlocale(LC_CTYPE, NULL)) == NULL || *s == NUL)
#  endif
            if ((s = getenv("LC_ALL")) == NULL || *s == NUL)
                if ((s = getenv("LC_CTYPE")) == NULL || *s == NUL)
                    s = getenv("LANG");

    if (s == NULL || *s == NUL)
        return FAIL;

    /* The most generic locale format is:
     * language[_territory][.codeset][@modifier][+special][,[sponsor][_revision]]
     * If there is a '.' remove the part before it.
     * if there is something after the codeset, remove it.
     * Make the name lowercase and replace '_' with '-'.
     * Exception: "ja_JP.EUC" == "euc-jp", "zh_CN.EUC" = "euc-cn",
     * "ko_KR.EUC" == "euc-kr"
     */
    if ((p = (char *)vim_strchr((char_u *)s, '.')) != NULL)
    {
        if (p > s + 2 && STRNICMP(p + 1, "EUC", 3) == 0
                        && !isalnum((int)p[4]) && p[4] != '-' && p[-3] == '_')
        {
            /* copy "XY.EUC" to "euc-XY" to buf[10] */
            STRCPY(buf + 10, "euc-");
            buf[14] = p[-2];
            buf[15] = p[-1];
            buf[16] = 0;
            s = buf + 10;
        }
        else
            s = p + 1;
    }
    for (i = 0; s[i] != NUL && i < (int)sizeof(buf) - 1; ++i)
    {
        if (s[i] == '_' || s[i] == '-')
            buf[i] = '-';
        else if (isalnum((int)s[i]))
            buf[i] = TOLOWER_ASC(s[i]);
        else
            break;
    }
    buf[i] = NUL;
#endif

    return enc_canonize((char_u *)buf);
}

#if defined(WIN3264) || defined(PROTO)
/*
 * Convert an encoding name to an MS-Windows codepage.
 * Returns zero if no codepage can be figured out.
 */
    int
encname2codepage(name)
    char_u      *name;
{
    int         cp;
    char_u      *p = name;
    int         idx;

    if (STRNCMP(p, "8bit-", 5) == 0)
        p += 5;
    else if (STRNCMP(p_enc, "2byte-", 6) == 0)
        p += 6;

    if (p[0] == 'c' && p[1] == 'p')
        cp = atoi(p + 2);
    else if ((idx = enc_canon_search(p)) >= 0)
        cp = enc_canon_table[idx].codepage;
    else
        return 0;
    if (IsValidCodePage(cp))
        return cp;
    return 0;
}
#endif

# if defined(USE_ICONV) || defined(PROTO)

static char_u *iconv_string __ARGS((vimconv_T *vcp, char_u *str, int slen, int *unconvlenp, int *resultlenp));

/*
 * Call iconv_open() with a check if iconv() works properly (there are broken
 * versions).
 * Returns (void *)-1 if failed.
 * (should return iconv_t, but that causes problems with prototypes).
 */
    void *
my_iconv_open(to, from)
    char_u      *to;
    char_u      *from;
{
    iconv_t     fd;
#define ICONV_TESTLEN 400
    char_u      tobuf[ICONV_TESTLEN];
    char        *p;
    size_t      tolen;
    static int  iconv_ok = -1;

    if (iconv_ok == FALSE)
        return (void *)-1;      /* detected a broken iconv() previously */

#ifdef DYNAMIC_ICONV
    /* Check if the iconv.dll can be found. */
    if (!iconv_enabled(TRUE))
        return (void *)-1;
#endif

    fd = iconv_open((char *)enc_skip(to), (char *)enc_skip(from));

    if (fd != (iconv_t)-1 && iconv_ok == -1)
    {
        /*
         * Do a dummy iconv() call to check if it actually works.  There is a
         * version of iconv() on Linux that is broken.  We can't ignore it,
         * because it's wide-spread.  The symptoms are that after outputting
         * the initial shift state the "to" pointer is NULL and conversion
         * stops for no apparent reason after about 8160 characters.
         */
        p = (char *)tobuf;
        tolen = ICONV_TESTLEN;
        (void)iconv(fd, NULL, NULL, &p, &tolen);
        if (p == NULL)
        {
            iconv_ok = FALSE;
            iconv_close(fd);
            fd = (iconv_t)-1;
        }
        else
            iconv_ok = TRUE;
    }

    return (void *)fd;
}

/*
 * Convert the string "str[slen]" with iconv().
 * If "unconvlenp" is not NULL handle the string ending in an incomplete
 * sequence and set "*unconvlenp" to the length of it.
 * Returns the converted string in allocated memory.  NULL for an error.
 * If resultlenp is not NULL, sets it to the result length in bytes.
 */
    static char_u *
iconv_string(vcp, str, slen, unconvlenp, resultlenp)
    vimconv_T   *vcp;
    char_u      *str;
    int         slen;
    int         *unconvlenp;
    int         *resultlenp;
{
    const char  *from;
    size_t      fromlen;
    char        *to;
    size_t      tolen;
    size_t      len = 0;
    size_t      done = 0;
    char_u      *result = NULL;
    char_u      *p;
    int         l;

    from = (char *)str;
    fromlen = slen;
    for (;;)
    {
        if (len == 0 || ICONV_ERRNO == ICONV_E2BIG)
        {
            /* Allocate enough room for most conversions.  When re-allocating
             * increase the buffer size. */
            len = len + fromlen * 2 + 40;
            p = alloc((unsigned)len);
            if (p != NULL && done > 0)
                mch_memmove(p, result, done);
            vim_free(result);
            result = p;
            if (result == NULL) /* out of memory */
                break;
        }

        to = (char *)result + done;
        tolen = len - done - 2;
        /* Avoid a warning for systems with a wrong iconv() prototype by
         * casting the second argument to void *. */
        if (iconv(vcp->vc_fd, (void *)&from, &fromlen, &to, &tolen)
                                                                != (size_t)-1)
        {
            /* Finished, append a NUL. */
            *to = NUL;
            break;
        }

        /* Check both ICONV_EINVAL and EINVAL, because the dynamically loaded
         * iconv library may use one of them. */
        if (!vcp->vc_fail && unconvlenp != NULL
                && (ICONV_ERRNO == ICONV_EINVAL || ICONV_ERRNO == EINVAL))
        {
            /* Handle an incomplete sequence at the end. */
            *to = NUL;
            *unconvlenp = (int)fromlen;
            break;
        }

        /* Check both ICONV_EILSEQ and EILSEQ, because the dynamically loaded
         * iconv library may use one of them. */
        else if (!vcp->vc_fail
                && (ICONV_ERRNO == ICONV_EILSEQ || ICONV_ERRNO == EILSEQ
                    || ICONV_ERRNO == ICONV_EINVAL || ICONV_ERRNO == EINVAL))
        {
            /* Can't convert: insert a '?' and skip a character.  This assumes
             * conversion from 'encoding' to something else.  In other
             * situations we don't know what to skip anyway. */
            *to++ = '?';
            if ((*mb_ptr2cells)((char_u *)from) > 1)
                *to++ = '?';
            if (enc_utf8)
                l = utfc_ptr2len_len((char_u *)from, (int)fromlen);
            else
            {
                l = (*mb_ptr2len)((char_u *)from);
                if (l > (int)fromlen)
                    l = (int)fromlen;
            }
            from += l;
            fromlen -= l;
        }
        else if (ICONV_ERRNO != ICONV_E2BIG)
        {
            /* conversion failed */
            vim_free(result);
            result = NULL;
            break;
        }
        /* Not enough room or skipping illegal sequence. */
        done = to - (char *)result;
    }

    if (resultlenp != NULL)
        *resultlenp = (int)(to - (char *)result);
    return result;
}

#  if defined(DYNAMIC_ICONV) || defined(PROTO)
/*
 * Dynamically load the "iconv.dll" on Win32.
 */

#ifndef DYNAMIC_ICONV       /* just generating prototypes */
# define HINSTANCE int
#endif
static HINSTANCE hIconvDLL = 0;
static HINSTANCE hMsvcrtDLL = 0;

#  ifndef DYNAMIC_ICONV_DLL
#   define DYNAMIC_ICONV_DLL "iconv.dll"
#   define DYNAMIC_ICONV_DLL_ALT "libiconv.dll"
#  endif
#  ifndef DYNAMIC_MSVCRT_DLL
#   define DYNAMIC_MSVCRT_DLL "msvcrt.dll"
#  endif

/*
 * Try opening the iconv.dll and return TRUE if iconv() can be used.
 */
    int
iconv_enabled(verbose)
    int         verbose;
{
    if (hIconvDLL != 0 && hMsvcrtDLL != 0)
        return TRUE;
    hIconvDLL = LoadLibrary(DYNAMIC_ICONV_DLL);
    if (hIconvDLL == 0)         /* sometimes it's called libiconv.dll */
        hIconvDLL = LoadLibrary(DYNAMIC_ICONV_DLL_ALT);
    if (hIconvDLL != 0)
        hMsvcrtDLL = LoadLibrary(DYNAMIC_MSVCRT_DLL);
    if (hIconvDLL == 0 || hMsvcrtDLL == 0)
    {
        /* Only give the message when 'verbose' is set, otherwise it might be
         * done whenever a conversion is attempted. */
        if (verbose && p_verbose > 0)
        {
            verbose_enter();
            EMSG2(_(e_loadlib),
                    hIconvDLL == 0 ? DYNAMIC_ICONV_DLL : DYNAMIC_MSVCRT_DLL);
            verbose_leave();
        }
        iconv_end();
        return FALSE;
    }

    iconv       = (void *)GetProcAddress(hIconvDLL, "libiconv");
    iconv_open  = (void *)GetProcAddress(hIconvDLL, "libiconv_open");
    iconv_close = (void *)GetProcAddress(hIconvDLL, "libiconv_close");
    iconvctl    = (void *)GetProcAddress(hIconvDLL, "libiconvctl");
    iconv_errno = (void *)GetProcAddress(hMsvcrtDLL, "_errno");
    if (iconv == NULL || iconv_open == NULL || iconv_close == NULL
            || iconvctl == NULL || iconv_errno == NULL)
    {
        iconv_end();
        if (verbose && p_verbose > 0)
        {
            verbose_enter();
            EMSG2(_(e_loadfunc), "for libiconv");
            verbose_leave();
        }
        return FALSE;
    }
    return TRUE;
}

    void
iconv_end()
{
    /* Don't use iconv() when inputting or outputting characters. */
    if (input_conv.vc_type == CONV_ICONV)
        convert_setup(&input_conv, NULL, NULL);
    if (output_conv.vc_type == CONV_ICONV)
        convert_setup(&output_conv, NULL, NULL);

    if (hIconvDLL != 0)
        FreeLibrary(hIconvDLL);
    if (hMsvcrtDLL != 0)
        FreeLibrary(hMsvcrtDLL);
    hIconvDLL = 0;
    hMsvcrtDLL = 0;
}
#  endif /* DYNAMIC_ICONV */
# endif /* USE_ICONV */

#endif /* FEAT_MBYTE */

#if defined(FEAT_XIM) || defined(PROTO)

# ifdef FEAT_GUI_MACVIM
   typedef int   GtkIMContext;
   typedef int * gpointer;
   typedef char  gchar;
#  define g_return_if_fail(x) if (!(x)) return;
# endif

# if defined(FEAT_GUI_GTK) || defined(FEAT_GUI_MACVIM)
static int xim_has_preediting INIT(= FALSE);  /* IM current status */

/*
 * Set preedit_start_col to the current cursor position.
 */
    static void
init_preedit_start_col(void)
{
    if (State & CMDLINE)
        preedit_start_col = cmdline_getvcol_cursor();
    else if (curwin != NULL)
        getvcol(curwin, &curwin->w_cursor, &preedit_start_col, NULL, NULL);
    /* Prevent that preediting marks the buffer as changed. */
    xim_changed_while_preediting = curbuf->b_changed;
}
# endif

# if (defined(HAVE_GTK2) || defined(FEAT_GUI_MACVIM)) && !defined(PROTO)

static int im_is_active        = FALSE; /* IM is enabled for current mode    */
static int preedit_is_active   = FALSE;
static int im_preedit_cursor   = 0;     /* cursor offset in characters       */
static int im_preedit_trailing = 0;     /* number of characters after cursor */

static unsigned long im_commit_handler_id  = 0;
# ifndef FEAT_GUI_MACVIM
static unsigned int  im_activatekey_keyval = GDK_VoidSymbol;
static unsigned int  im_activatekey_state  = 0;
# endif

# ifndef FEAT_GUI_MACVIM
    void
im_set_active(int active)
{
    int was_active;

    was_active = !!im_is_active;
    im_is_active = (active && !p_imdisable);

    if (im_is_active != was_active)
        xim_reset();
}
# endif

    void
xim_set_focus(int focus)
{
# ifndef FEAT_GUI_MACVIM
    if (xic != NULL)
    {
        if (focus)
            gtk_im_context_focus_in(xic);
        else
            gtk_im_context_focus_out(xic);
    }
# endif
}

# ifndef FEAT_GUI_MACVIM
    void
im_set_position(int row, int col)
{
    if (xic != NULL)
    {
        GdkRectangle area;

        area.x = FILL_X(col);
        area.y = FILL_Y(row);
        area.width  = gui.char_width * (mb_lefthalve(row, col) ? 2 : 1);
        area.height = gui.char_height;

        gtk_im_context_set_cursor_location(xic, &area);
    }
}
# endif

#  if 0 || defined(PROTO) /* apparently only used in gui_x11.c */
    void
xim_set_preedit(void)
{
    im_set_position(gui.row, gui.col);
}
#  endif

    static void
im_add_to_input(char_u *str, int len)
{
    /* Convert from 'termencoding' (always "utf-8") to 'encoding' */
    if (input_conv.vc_type != CONV_NONE)
    {
        str = string_convert(&input_conv, str, &len);
        g_return_if_fail(str != NULL);
    }

    add_to_input_buf_csi(str, len);

    if (input_conv.vc_type != CONV_NONE)
        vim_free(str);

# ifndef FEAT_GUI_MACVIM
    if (p_mh) /* blank out the pointer if necessary */
        gui_mch_mousehide(TRUE);
# endif
}

    static void
im_delete_preedit(void)
{
    char_u bskey[]  = {CSI, 'k', 'b'};
    char_u delkey[] = {CSI, 'k', 'D'};

    if (State & NORMAL)
    {
        im_preedit_cursor = 0;
        return;
    }
    for (; im_preedit_cursor > 0; --im_preedit_cursor)
        add_to_input_buf(bskey, (int)sizeof(bskey));

    for (; im_preedit_trailing > 0; --im_preedit_trailing)
        add_to_input_buf(delkey, (int)sizeof(delkey));
}

/*
 * Move the cursor left by "num_move_back" characters.
 * Note that ins_left() checks im_is_preediting() to avoid breaking undo for
 * these K_LEFT keys.
 */
    static void
im_correct_cursor(int num_move_back)
{
    char_u backkey[] = {CSI, 'k', 'l'};

    if (State & NORMAL)
        return;
#  ifdef FEAT_RIGHTLEFT
    if ((State & CMDLINE) == 0 && curwin != NULL && curwin->w_p_rl)
        backkey[2] = 'r';
#  endif
    for (; num_move_back > 0; --num_move_back)
        add_to_input_buf(backkey, (int)sizeof(backkey));
}

# ifndef FEAT_GUI_MACVIM
static int xim_expected_char = NUL;
static int xim_ignored_char = FALSE;
# endif

/*
 * Update the mode and cursor while in an IM callback.
 */
    static void
im_show_info(void)
{
    int     old_vgetc_busy;

    old_vgetc_busy = vgetc_busy;
    vgetc_busy = TRUE;
    showmode();
    vgetc_busy = old_vgetc_busy;
    setcursor();
    out_flush();
}

# ifndef FEAT_GUI_MACVIM
/*
 * Callback invoked when the user finished preediting.
 * Put the final string into the input buffer.
 */
    static void
im_commit_cb(GtkIMContext *context UNUSED,
             const gchar *str,
             gpointer data UNUSED)
{
    int slen = (int)STRLEN(str);
    int add_to_input = TRUE;
    int clen;
    int len = slen;
    int commit_with_preedit = TRUE;
    char_u      *im_str, *p;

#ifdef XIM_DEBUG
    xim_log("im_commit_cb(): %s\n", str);
#endif

    /* The imhangul module doesn't reset the preedit string before
     * committing.  Call im_delete_preedit() to work around that. */
    im_delete_preedit();

    /* Indicate that preediting has finished. */
    if (preedit_start_col == MAXCOL)
    {
        init_preedit_start_col();
        commit_with_preedit = FALSE;
    }

    /* The thing which setting "preedit_start_col" to MAXCOL means that
     * "preedit_start_col" will be set forcely when calling
     * preedit_changed_cb() next time.
     * "preedit_start_col" should not reset with MAXCOL on this part. Vim
     * is simulating the preediting by using add_to_input_str(). when
     * preedit begin immediately before committed, the typebuf is not
     * flushed to screen, then it can't get correct "preedit_start_col".
     * Thus, it should calculate the cells by adding cells of the committed
     * string. */
    if (input_conv.vc_type != CONV_NONE)
    {
        im_str = string_convert(&input_conv, (char_u *)str, &len);
        g_return_if_fail(im_str != NULL);
    }
    else
        im_str = (char_u *)str;
    clen = 0;
    for (p = im_str; p < im_str + len; p += (*mb_ptr2len)(p))
        clen += (*mb_ptr2cells)(p);
    if (input_conv.vc_type != CONV_NONE)
        vim_free(im_str);
    preedit_start_col += clen;

    /* Is this a single character that matches a keypad key that's just
     * been pressed?  If so, we don't want it to be entered as such - let
     * us carry on processing the raw keycode so that it may be used in
     * mappings as <kSomething>. */
    if (xim_expected_char != NUL)
    {
        /* We're currently processing a keypad or other special key */
        if (slen == 1 && str[0] == xim_expected_char)
        {
            /* It's a match - don't do it here */
            xim_ignored_char = TRUE;
            add_to_input = FALSE;
        }
        else
        {
            /* Not a match */
            xim_ignored_char = FALSE;
        }
    }

    if (add_to_input)
        im_add_to_input((char_u *)str, slen);

    /* Inserting chars while "im_is_active" is set does not cause a change of
     * buffer.  When the chars are committed the buffer must be marked as
     * changed. */
    if (!commit_with_preedit)
        preedit_start_col = MAXCOL;

    /* This flag is used in changed() at next call. */
    xim_changed_while_preediting = TRUE;

    if (gtk_main_level() > 0)
        gtk_main_quit();
}
# endif

/*
 * Callback invoked after start to the preedit.
 */
# ifndef FEAT_GUI_MACVIM
    static void
im_preedit_start_cb(GtkIMContext *context UNUSED, gpointer data UNUSED)
# else
    void
im_preedit_start_macvim()
# endif
{
#ifdef XIM_DEBUG
    xim_log("im_preedit_start_cb()\n");
#endif

    im_is_active = TRUE;
    preedit_is_active = TRUE;
    gui_update_cursor(TRUE, FALSE);
    im_show_info();
}

/*
 * Callback invoked after end to the preedit.
 */
# ifndef FEAT_GUI_MACVIM
    static void
im_preedit_end_cb(GtkIMContext *context UNUSED, gpointer data UNUSED)
# else
    void
im_preedit_end_macvim()
# endif
{
#ifdef XIM_DEBUG
    xim_log("im_preedit_end_cb()\n");
#endif
    im_delete_preedit();

    /* Indicate that preediting has finished */
    preedit_start_col = MAXCOL;
    xim_has_preediting = FALSE;

#if 0
    /* Removal of this line suggested by Takuhiro Nishioka.  Fixes that IM was
     * switched off unintentionally.  We now use preedit_is_active (added by
     * SungHyun Nam). */
    im_is_active = FALSE;
#endif
    preedit_is_active = FALSE;
    gui_update_cursor(TRUE, FALSE);
    im_show_info();
}

/*
 * Callback invoked after changes to the preedit string.  If the preedit
 * string was empty before, remember the preedit start column so we know
 * where to apply feedback attributes.  Delete the previous preedit string
 * if there was one, save the new preedit cursor offset, and put the new
 * string into the input buffer.
 *
 * TODO: The pragmatic "put into input buffer" approach used here has
 *       several fundamental problems:
 *
 * - The characters in the preedit string are subject to remapping.
 *   That's broken, only the finally committed string should be remapped.
 *
 * - There is a race condition involved:  The retrieved value for the
 *   current cursor position will be wrong if any unprocessed characters
 *   are still queued in the input buffer.
 *
 * - Due to the lack of synchronization between the file buffer in memory
 *   and any typed characters, it's practically impossible to implement the
 *   "retrieve_surrounding" and "delete_surrounding" signals reliably.  IM
 *   modules for languages such as Thai are likely to rely on this feature
 *   for proper operation.
 *
 * Conclusions:  I think support for preediting needs to be moved to the
 * core parts of Vim.  Ideally, until it has been committed, the preediting
 * string should only be displayed and not affect the buffer content at all.
 * The question how to deal with the synchronization issue still remains.
 * Circumventing the input buffer is probably not desirable.  Anyway, I think
 * implementing "retrieve_surrounding" is the only hard problem.
 *
 * One way to solve all of this in a clean manner would be to queue all key
 * press/release events "as is" in the input buffer, and apply the IM filtering
 * at the receiving end of the queue.  This, however, would have a rather large
 * impact on the code base.  If there is an easy way to force processing of all
 * remaining input from within the "retrieve_surrounding" signal handler, this
 * might not be necessary.  Gotta ask on vim-dev for opinions.
 */
# ifndef FEAT_GUI_MACVIM
    static void
im_preedit_changed_cb(GtkIMContext *context, gpointer data UNUSED)
# else
    void
im_preedit_changed_macvim(char *preedit_string, int cursor_index)
# endif
{
# ifndef FEAT_GUI_MACVIM
    char    *preedit_string = NULL;
    int     cursor_index    = 0;
# endif
    int     num_move_back   = 0;
    char_u  *str;
    char_u  *p;
    int     i;

# ifndef FEAT_GUI_MACVIM
    gtk_im_context_get_preedit_string(context,
                                      &preedit_string, NULL,
                                      &cursor_index);
# endif

#ifdef XIM_DEBUG
    xim_log("im_preedit_changed_cb(): %s\n", preedit_string);
#endif

    g_return_if_fail(preedit_string != NULL); /* just in case */

    /* If preedit_start_col is MAXCOL set it to the current cursor position. */
    if (preedit_start_col == MAXCOL && preedit_string[0] != '\0')
    {
        xim_has_preediting = TRUE;

        /* Urgh, this breaks if the input buffer isn't empty now */
        init_preedit_start_col();
    }
    else if (cursor_index == 0 && preedit_string[0] == '\0')
    {
        xim_has_preediting = FALSE;

        /* If at the start position (after typing backspace)
         * preedit_start_col must be reset. */
        preedit_start_col = MAXCOL;
    }

    im_delete_preedit();

    /*
     * Compute the end of the preediting area: "preedit_end_col".
     * According to the documentation of gtk_im_context_get_preedit_string(),
     * the cursor_pos output argument returns the offset in bytes.  This is
     * unfortunately not true -- real life shows the offset is in characters,
     * and the GTK+ source code agrees with me.  Will file a bug later.
     */
    if (preedit_start_col != MAXCOL)
        preedit_end_col = preedit_start_col;
    str = (char_u *)preedit_string;
    for (p = str, i = 0; *p != NUL; p += utf_byte2len(*p), ++i)
    {
        int is_composing;

        is_composing = ((*p & 0x80) != 0 && utf_iscomposing(utf_ptr2char(p)));
        /*
         * These offsets are used as counters when generating <BS> and <Del>
         * to delete the preedit string.  So don't count composing characters
         * unless 'delcombine' is enabled.
         */
        if (!is_composing || p_deco)
        {
            if (i < cursor_index)
                ++im_preedit_cursor;
            else
                ++im_preedit_trailing;
        }
        if (!is_composing && i >= cursor_index)
        {
            /* This is essentially the same as im_preedit_trailing, except
             * composing characters are not counted even if p_deco is set. */
            ++num_move_back;
        }
        if (preedit_start_col != MAXCOL)
            preedit_end_col += utf_ptr2cells(p);
    }

    if (p > str)
    {
        im_add_to_input(str, (int)(p - str));
        im_correct_cursor(num_move_back);
    }

# ifndef FEAT_GUI_MACVIM
    g_free(preedit_string);

    if (gtk_main_level() > 0)
        gtk_main_quit();
# endif
}

# ifndef FEAT_GUI_MACVIM
/*
 * Translate the Pango attributes at iter to Vim highlighting attributes.
 * Ignore attributes not supported by Vim highlighting.  This shouldn't have
 * too much impact -- right now we handle even more attributes than necessary
 * for the IM modules I tested with.
 */
    static int
translate_pango_attributes(PangoAttrIterator *iter)
{
    PangoAttribute  *attr;
    int             char_attr = HL_NORMAL;

    attr = pango_attr_iterator_get(iter, PANGO_ATTR_UNDERLINE);
    if (attr != NULL && ((PangoAttrInt *)attr)->value
                                                 != (int)PANGO_UNDERLINE_NONE)
        char_attr |= HL_UNDERLINE;

    attr = pango_attr_iterator_get(iter, PANGO_ATTR_WEIGHT);
    if (attr != NULL && ((PangoAttrInt *)attr)->value >= (int)PANGO_WEIGHT_BOLD)
        char_attr |= HL_BOLD;

    attr = pango_attr_iterator_get(iter, PANGO_ATTR_STYLE);
    if (attr != NULL && ((PangoAttrInt *)attr)->value
                                                   != (int)PANGO_STYLE_NORMAL)
        char_attr |= HL_ITALIC;

    attr = pango_attr_iterator_get(iter, PANGO_ATTR_BACKGROUND);
    if (attr != NULL)
    {
        const PangoColor *color = &((PangoAttrColor *)attr)->color;

        /* Assume inverse if black background is requested */
        if ((color->red | color->green | color->blue) == 0)
            char_attr |= HL_INVERSE;
    }

    return char_attr;
}
# endif

/*
 * Retrieve the highlighting attributes at column col in the preedit string.
 * Return -1 if not in preediting mode or if col is out of range.
 */
    int
im_get_feedback_attr(int col)
{
# ifndef FEAT_GUI_MACVIM
    char            *preedit_string = NULL;
    PangoAttrList   *attr_list      = NULL;
    int             char_attr       = -1;

    if (xic == NULL)
        return char_attr;

    gtk_im_context_get_preedit_string(xic, &preedit_string, &attr_list, NULL);

    if (preedit_string != NULL && attr_list != NULL)
    {
        int idx;

        /* Get the byte index as used by PangoAttrIterator */
        for (idx = 0; col > 0 && preedit_string[idx] != '\0'; --col)
            idx += utfc_ptr2len((char_u *)preedit_string + idx);

        if (preedit_string[idx] != '\0')
        {
            PangoAttrIterator   *iter;
            int                 start, end;

            char_attr = HL_NORMAL;
            iter = pango_attr_list_get_iterator(attr_list);

            /* Extract all relevant attributes from the list. */
            do
            {
                pango_attr_iterator_range(iter, &start, &end);

                if (idx >= start && idx < end)
                    char_attr |= translate_pango_attributes(iter);
            }
            while (pango_attr_iterator_next(iter));

            pango_attr_iterator_destroy(iter);
        }
    }

    if (attr_list != NULL)
        pango_attr_list_unref(attr_list);
    g_free(preedit_string);

    return char_attr;
# else
    return HL_UNDERLINE;
# endif
}

    void
xim_init(void)
{
#ifdef XIM_DEBUG
    xim_log("xim_init()\n");
#endif

# ifndef FEAT_GUI_MACVIM
    g_return_if_fail(gui.drawarea != NULL);
    g_return_if_fail(gui.drawarea->window != NULL);

    xic = gtk_im_multicontext_new();
    g_object_ref(xic);

    im_commit_handler_id = g_signal_connect(G_OBJECT(xic), "commit",
                                            G_CALLBACK(&im_commit_cb), NULL);
    g_signal_connect(G_OBJECT(xic), "preedit_changed",
                     G_CALLBACK(&im_preedit_changed_cb), NULL);
    g_signal_connect(G_OBJECT(xic), "preedit_start",
                     G_CALLBACK(&im_preedit_start_cb), NULL);
    g_signal_connect(G_OBJECT(xic), "preedit_end",
                     G_CALLBACK(&im_preedit_end_cb), NULL);

    gtk_im_context_set_client_window(xic, gui.drawarea->window);
# endif
}

    void
im_shutdown(void)
{
#ifdef XIM_DEBUG
    xim_log("im_shutdown()\n");
#endif

# ifndef FEAT_GUI_MACVIM
    if (xic != NULL)
    {
        gtk_im_context_focus_out(xic);
        g_object_unref(xic);
        xic = NULL;
    }
# endif
    im_is_active = FALSE;
    im_commit_handler_id = 0;
    preedit_start_col = MAXCOL;
    xim_has_preediting = FALSE;
}

# ifndef FEAT_GUI_MACVIM
/*
 * Convert the string argument to keyval and state for GdkEventKey.
 * If str is valid return TRUE, otherwise FALSE.
 *
 * See 'imactivatekey' for documentation of the format.
 */
    static int
im_string_to_keyval(const char *str, unsigned int *keyval, unsigned int *state)
{
    const char      *mods_end;
    unsigned        tmp_keyval;
    unsigned        tmp_state = 0;

    mods_end = strrchr(str, '-');
    mods_end = (mods_end != NULL) ? mods_end + 1 : str;

    /* Parse modifier keys */
    while (str < mods_end)
        switch (*str++)
        {
            case '-':                                                   break;
            case 'S': case 's': tmp_state |= (unsigned)GDK_SHIFT_MASK;  break;
            case 'L': case 'l': tmp_state |= (unsigned)GDK_LOCK_MASK;   break;
            case 'C': case 'c': tmp_state |= (unsigned)GDK_CONTROL_MASK;break;
            case '1':           tmp_state |= (unsigned)GDK_MOD1_MASK;   break;
            case '2':           tmp_state |= (unsigned)GDK_MOD2_MASK;   break;
            case '3':           tmp_state |= (unsigned)GDK_MOD3_MASK;   break;
            case '4':           tmp_state |= (unsigned)GDK_MOD4_MASK;   break;
            case '5':           tmp_state |= (unsigned)GDK_MOD5_MASK;   break;
            default:
                return FALSE;
        }

    tmp_keyval = gdk_keyval_from_name(str);

    if (tmp_keyval == 0 || tmp_keyval == GDK_VoidSymbol)
        return FALSE;

    if (keyval != NULL)
        *keyval = tmp_keyval;
    if (state != NULL)
        *state = tmp_state;

    return TRUE;
}

/*
 * Return TRUE if p_imak is valid, otherwise FALSE.  As a special case, an
 * empty string is also regarded as valid.
 *
 * Note: The numerical key value of p_imak is cached if it was valid; thus
 * boldly assuming im_xim_isvalid_imactivate() will always be called whenever
 * 'imak' changes.  This is currently the case but not obvious -- should
 * probably rename the function for clarity.
 */
    int
im_xim_isvalid_imactivate(void)
{
    if (p_imak[0] == NUL)
    {
        im_activatekey_keyval = GDK_VoidSymbol;
        im_activatekey_state  = 0;
        return TRUE;
    }

    return im_string_to_keyval((const char *)p_imak,
                               &im_activatekey_keyval,
                               &im_activatekey_state);
}

    static void
im_synthesize_keypress(unsigned int keyval, unsigned int state)
{
    GdkEventKey *event;

#  ifdef HAVE_GTK_MULTIHEAD
    event = (GdkEventKey *)gdk_event_new(GDK_KEY_PRESS);
    g_object_ref(gui.drawarea->window); /* unreffed by gdk_event_free() */
#  else
    event = (GdkEventKey *)g_malloc0((gulong)sizeof(GdkEvent));
    event->type = GDK_KEY_PRESS;
#  endif
    event->window = gui.drawarea->window;
    event->send_event = TRUE;
    event->time = GDK_CURRENT_TIME;
    event->state  = state;
    event->keyval = keyval;
    event->hardware_keycode = /* needed for XIM */
        XKeysymToKeycode(GDK_WINDOW_XDISPLAY(event->window), (KeySym)keyval);
    event->length = 0;
    event->string = NULL;

    gtk_im_context_filter_keypress(xic, event);

    /* For consistency, also send the corresponding release event. */
    event->type = GDK_KEY_RELEASE;
    event->send_event = FALSE;
    gtk_im_context_filter_keypress(xic, event);

#  ifdef HAVE_GTK_MULTIHEAD
    gdk_event_free((GdkEvent *)event);
#  else
    g_free(event);
#  endif
}
# endif // FEAT_GUI_MACVIM

    void
xim_reset(void)
{
# ifndef FEAT_GUI_MACVIM
    if (xic != NULL)
    {
        /*
         * The third-party imhangul module (and maybe others too) ignores
         * gtk_im_context_reset() or at least doesn't reset the active state.
         * Thus sending imactivatekey would turn it off if it was on before,
         * which is clearly not what we want.  Fortunately we can work around
         * that for imhangul by sending GDK_Escape, but I don't know if it
         * works with all IM modules that support an activation key :/
         *
         * An alternative approach would be to destroy the IM context and
         * recreate it.  But that means loading/unloading the IM module on
         * every mode switch, which causes a quite noticable delay even on
         * my rather fast box...
         * *
         * Moreover, there are some XIM which cannot respond to
         * im_synthesize_keypress(). we hope that they reset by
         * xim_shutdown().
         */
        if (im_activatekey_keyval != GDK_VoidSymbol && im_is_active)
            im_synthesize_keypress(GDK_Escape, 0U);

        gtk_im_context_reset(xic);

        /*
         * HACK for Ami: This sequence of function calls makes Ami handle
         * the IM reset graciously, without breaking loads of other stuff.
         * It seems to force English mode as well, which is exactly what we
         * want because it makes the Ami status display work reliably.
         */
        gtk_im_context_set_use_preedit(xic, FALSE);

        if (p_imdisable)
            im_shutdown();
        else
        {
            gtk_im_context_set_use_preedit(xic, TRUE);
            xim_set_focus(gui.in_focus);

            if (im_activatekey_keyval != GDK_VoidSymbol)
            {
                if (im_is_active)
                {
                    g_signal_handler_block(xic, im_commit_handler_id);
                    im_synthesize_keypress(im_activatekey_keyval,
                                                    im_activatekey_state);
                    g_signal_handler_unblock(xic, im_commit_handler_id);
                }
            }
            else
            {
                im_shutdown();
                xim_init();
                xim_set_focus(gui.in_focus);
            }
        }
    }
# endif

    preedit_start_col = MAXCOL;
    xim_has_preediting = FALSE;
}

# ifndef FEAT_GUI_MACVIM
    int
xim_queue_key_press_event(GdkEventKey *event, int down)
{
    if (down)
    {
        /*
         * Workaround GTK2 XIM 'feature' that always converts keypad keys to
         * chars., even when not part of an IM sequence (ref. feature of
         * gdk/gdkkeyuni.c).
         * Flag any keypad keys that might represent a single char.
         * If this (on its own - i.e., not part of an IM sequence) is
         * committed while we're processing one of these keys, we can ignore
         * that commit and go ahead & process it ourselves.  That way we can
         * still distinguish keypad keys for use in mappings.
         * Also add GDK_space to make <S-Space> work.
         */
        switch (event->keyval)
        {
            case GDK_KP_Add:      xim_expected_char = '+';  break;
            case GDK_KP_Subtract: xim_expected_char = '-';  break;
            case GDK_KP_Divide:   xim_expected_char = '/';  break;
            case GDK_KP_Multiply: xim_expected_char = '*';  break;
            case GDK_KP_Decimal:  xim_expected_char = '.';  break;
            case GDK_KP_Equal:    xim_expected_char = '=';  break;
            case GDK_KP_0:        xim_expected_char = '0';  break;
            case GDK_KP_1:        xim_expected_char = '1';  break;
            case GDK_KP_2:        xim_expected_char = '2';  break;
            case GDK_KP_3:        xim_expected_char = '3';  break;
            case GDK_KP_4:        xim_expected_char = '4';  break;
            case GDK_KP_5:        xim_expected_char = '5';  break;
            case GDK_KP_6:        xim_expected_char = '6';  break;
            case GDK_KP_7:        xim_expected_char = '7';  break;
            case GDK_KP_8:        xim_expected_char = '8';  break;
            case GDK_KP_9:        xim_expected_char = '9';  break;
            case GDK_space:       xim_expected_char = ' ';  break;
            default:              xim_expected_char = NUL;
        }
        xim_ignored_char = FALSE;
    }

    /*
     * When typing fFtT, XIM may be activated. Thus it must pass
     * gtk_im_context_filter_keypress() in Normal mode.
     * And while doing :sh too.
     */
    if (xic != NULL && !p_imdisable
                    && (State & (INSERT | CMDLINE | NORMAL | EXTERNCMD)) != 0)
    {
        /*
         * Filter 'imactivatekey' and map it to CTRL-^.  This way, Vim is
         * always aware of the current status of IM, and can even emulate
         * the activation key for modules that don't support one.
         */
        if (event->keyval == im_activatekey_keyval
             && (event->state & im_activatekey_state) == im_activatekey_state)
        {
            unsigned int state_mask;

            /* Require the state of the 3 most used modifiers to match exactly.
             * Otherwise e.g. <S-C-space> would be unusable for other purposes
             * if the IM activate key is <S-space>. */
            state_mask  = im_activatekey_state;
            state_mask |= ((int)GDK_SHIFT_MASK | (int)GDK_CONTROL_MASK
                                                        | (int)GDK_MOD1_MASK);

            if ((event->state & state_mask) != im_activatekey_state)
                return FALSE;

            /* Don't send it a second time on GDK_KEY_RELEASE. */
            if (event->type != GDK_KEY_PRESS)
                return TRUE;

            if (map_to_exists_mode((char_u *)"", LANGMAP, FALSE))
            {
                im_set_active(FALSE);

                /* ":lmap" mappings exists, toggle use of mappings. */
                State ^= LANGMAP;
                if (State & LANGMAP)
                {
                    curbuf->b_p_iminsert = B_IMODE_NONE;
                    State &= ~LANGMAP;
                }
                else
                {
                    curbuf->b_p_iminsert = B_IMODE_LMAP;
                    State |= LANGMAP;
                }
                return TRUE;
            }

            return gtk_im_context_filter_keypress(xic, event);
        }

        /* Don't filter events through the IM context if IM isn't active
         * right now.  Unlike with GTK+ 1.2 we cannot rely on the IM module
         * not doing anything before the activation key was sent. */
        if (im_activatekey_keyval == GDK_VoidSymbol || im_is_active)
        {
            int imresult = gtk_im_context_filter_keypress(xic, event);

            /* Some XIM send following sequence:
             * 1. preedited string.
             * 2. committed string.
             * 3. line changed key.
             * 4. preedited string.
             * 5. remove preedited string.
             * if 3, Vim can't move back the above line for 5.
             * thus, this part should not parse the key. */
            if (!imresult && preedit_start_col != MAXCOL
                                               && event->keyval == GDK_Return)
            {
                im_synthesize_keypress(GDK_Return, 0U);
                return FALSE;
            }

            /* If XIM tried to commit a keypad key as a single char.,
             * ignore it so we can use the keypad key 'raw', for mappings. */
            if (xim_expected_char != NUL && xim_ignored_char)
                /* We had a keypad key, and XIM tried to thieve it */
                return FALSE;

            /* Normal processing */
            return imresult;
        }
    }

    return FALSE;
}
# endif

# ifndef FEAT_GUI_MACVIM
    int
im_get_status(void)
{
    return im_is_active;
}
# endif

# else /* !HAVE_GTK2 */

static int      xim_is_active = FALSE;  /* XIM should be active in the current
                                           mode */
static int      xim_has_focus = FALSE;  /* XIM is really being used for Vim */
#ifdef FEAT_GUI_X11
static XIMStyle input_style;
static int      status_area_enabled = TRUE;
#endif

#ifdef FEAT_GUI_GTK
# ifdef WIN3264
#  include <gdk/gdkwin32.h>
# else
#  include <gdk/gdkx.h>
# endif
#else
# ifdef PROTO
/* Define a few things to be able to generate prototypes while not configured
 * for GTK. */
#  define GSList int
#  define gboolean int
   typedef int GdkEvent;
   typedef int GdkEventKey;
#  define GdkIC int
# endif
#endif

#if defined(FEAT_GUI_GTK) || defined(PROTO)
static int      preedit_buf_len = 0;
static int      xim_can_preediting INIT(= FALSE);       /* XIM in showmode() */
static int      xim_input_style;
#ifndef FEAT_GUI_GTK
# define gboolean int
#endif
static gboolean use_status_area = 0;

static int im_xim_str2keycode __ARGS((unsigned int *code, unsigned int *state));
static void im_xim_send_event_imactivate __ARGS((void));

/*
 * Convert string to keycode and state for XKeyEvent.
 * When string is valid return OK, when invalid return FAIL.
 *
 * See 'imactivatekey' documentation for the format.
 */
    static int
im_xim_str2keycode(code, state)
    unsigned int *code;
    unsigned int *state;
{
    int         retval = OK;
    int         len;
    unsigned    keycode = 0, keystate = 0;
    Window      window;
    Display     *display;
    char_u      *flag_end;
    char_u      *str;

    if (*p_imak != NUL)
    {
        len = STRLEN(p_imak);
        for (flag_end = p_imak + len - 1;
                            flag_end > p_imak && *flag_end != '-'; --flag_end)
            ;

        /* Parse modifier keys */
        for (str = p_imak; str < flag_end; ++str)
        {
            switch (*str)
            {
                case 's': case 'S':
                    keystate |= ShiftMask;
                    break;
                case 'l': case 'L':
                    keystate |= LockMask;
                    break;
                case 'c': case 'C':
                    keystate |= ControlMask;
                    break;
                case '1':
                    keystate |= Mod1Mask;
                    break;
                case '2':
                    keystate |= Mod2Mask;
                    break;
                case '3':
                    keystate |= Mod3Mask;
                    break;
                case '4':
                    keystate |= Mod4Mask;
                    break;
                case '5':
                    keystate |= Mod5Mask;
                    break;
                case '-':
                    break;
                default:
                    retval = FAIL;
            }
        }
        if (*str == '-')
            ++str;

        /* Get keycode from string. */
        gui_get_x11_windis(&window, &display);
        if (display)
            keycode = XKeysymToKeycode(display, XStringToKeysym((char *)str));
        if (keycode == 0)
            retval = FAIL;

        if (code != NULL)
            *code = keycode;
        if (state != NULL)
            *state = keystate;
    }
    return retval;
}

    static void
im_xim_send_event_imactivate()
{
    /* Force turn on preedit state by symulate keypress event.
     * Keycode and state is specified by 'imactivatekey'.
     */
    XKeyEvent ev;

    gui_get_x11_windis(&ev.window, &ev.display);
    ev.root = RootWindow(ev.display, DefaultScreen(ev.display));
    ev.subwindow = None;
    ev.time = CurrentTime;
    ev.x = 1;
    ev.y = 1;
    ev.x_root = 1;
    ev.y_root = 1;
    ev.same_screen = 1;
    ev.type = KeyPress;
    if (im_xim_str2keycode(&ev.keycode, &ev.state) == OK)
        XSendEvent(ev.display, ev.window, 1, KeyPressMask, (XEvent*)&ev);
}

/*
 * Return TRUE if 'imactivatekey' has a valid value.
 */
    int
im_xim_isvalid_imactivate()
{
    return im_xim_str2keycode(NULL, NULL) == OK;
}
#endif /* FEAT_GUI_GTK */

/*
 * Switch using XIM on/off.  This is used by the code that changes "State".
 */
    void
im_set_active(active)
    int         active;
{
    if (xic == NULL)
        return;

    /* If 'imdisable' is set, XIM is never active. */
    if (p_imdisable)
        active = FALSE;
#if !defined (FEAT_GUI_GTK)
    else if (input_style & XIMPreeditPosition)
        /* There is a problem in switching XIM off when preediting is used,
         * and it is not clear how this can be solved.  For now, keep XIM on
         * all the time, like it was done in Vim 5.8. */
        active = TRUE;
#endif

    /* Remember the active state, it is needed when Vim gets keyboard focus. */
    xim_is_active = active;

#ifdef FEAT_GUI_GTK
    /* When 'imactivatekey' has valid key-string, try to control XIM preedit
     * state.  When 'imactivatekey' has no or invalid string, try old XIM
     * focus control.
     */
    if (*p_imak != NUL)
    {
        /* BASIC STRATEGY:
         * Destroy old Input Context (XIC), and create new one.  New XIC
         * would have a state of preedit that is off.  When argument:active
         * is false, that's all.  Else argument:active is true, send a key
         * event specified by 'imactivatekey' to activate XIM preedit state.
         */

        xim_is_active = TRUE; /* Disable old XIM focus control */
        /* If we can monitor preedit state with preedit callback functions,
         * try least creation of new XIC.
         */
        if (xim_input_style & (int)GDK_IM_PREEDIT_CALLBACKS)
        {
            if (xim_can_preediting && !active)
            {
                /* Force turn off preedit state.  With some IM
                 * implementations, we cannot turn off preedit state by
                 * symulate keypress event.  It is why using such a method
                 * that destroy old IC (input context), and create new one.
                 * When create new IC, its preedit state is usually off.
                 */
                xim_reset();
                xim_set_focus(FALSE);
                gdk_ic_destroy(xic);
                xim_init();
                xim_can_preediting = FALSE;
            }
            else if (!xim_can_preediting && active)
                im_xim_send_event_imactivate();
        }
        else
        {
            /* First, force destroy old IC, and create new one.  It
             * symulates "turning off preedit state".
             */
            xim_set_focus(FALSE);
            gdk_ic_destroy(xic);
            xim_init();
            xim_can_preediting = FALSE;

            /* 2nd, when requested to activate IM, symulate this by sending
             * the event.
             */
            if (active)
            {
                im_xim_send_event_imactivate();
                xim_can_preediting = TRUE;
            }
        }
    }
    else
    {
# ifndef XIMPreeditUnKnown
        /* X11R5 doesn't have these, it looks safe enough to define here. */
        typedef unsigned long XIMPreeditState;
#  define XIMPreeditUnKnown     0L
#  define XIMPreeditEnable      1L
#  define XIMPreeditDisable     (1L<<1)
#  define XNPreeditState        "preeditState"
# endif
        XIMPreeditState preedit_state = XIMPreeditUnKnown;
        XVaNestedList preedit_attr;
        XIC pxic;

        preedit_attr = XVaCreateNestedList(0,
                                XNPreeditState, &preedit_state,
                                NULL);
        pxic = ((GdkICPrivate *)xic)->xic;

        if (!XGetICValues(pxic, XNPreeditAttributes, preedit_attr, NULL))
        {
            XFree(preedit_attr);
            preedit_attr = XVaCreateNestedList(0,
                                XNPreeditState,
                                active ? XIMPreeditEnable : XIMPreeditDisable,
                                NULL);
            XSetICValues(pxic, XNPreeditAttributes, preedit_attr, NULL);
            xim_can_preediting = active;
            xim_is_active = active;
        }
        XFree(preedit_attr);
    }
    if (xim_input_style & XIMPreeditCallbacks)
    {
        preedit_buf_len = 0;
        init_preedit_start_col();
    }
#else
# if 0
        /* When had tested kinput2 + canna + Athena GUI version with
         * 'imactivatekey' is "s-space", im_xim_send_event_imactivate() did not
         * work correctly.  It just inserted one space.  I don't know why we
         * couldn't switch state of XIM preediting.  This is reason why these
         * codes are commented out.
         */
        /* First, force destroy old IC, and create new one.  It symulates
         * "turning off preedit state".
         */
        xim_set_focus(FALSE);
        XDestroyIC(xic);
        xic = NULL;
        xim_init();

        /* 2nd, when requested to activate IM, symulate this by sending the
         * event.
         */
        if (active)
            im_xim_send_event_imactivate();
# endif
#endif
    xim_set_preedit();
}

/*
 * Adjust using XIM for gaining or losing keyboard focus.  Also called when
 * "xim_is_active" changes.
 */
    void
xim_set_focus(focus)
    int         focus;
{
    if (xic == NULL)
        return;

    /*
     * XIM only gets focus when the Vim window has keyboard focus and XIM has
     * been set active for the current mode.
     */
    if (focus && xim_is_active)
    {
        if (!xim_has_focus)
        {
            xim_has_focus = TRUE;
#ifdef FEAT_GUI_GTK
            gdk_im_begin(xic, gui.drawarea->window);
#else
            XSetICFocus(xic);
#endif
        }
    }
    else
    {
        if (xim_has_focus)
        {
            xim_has_focus = FALSE;
#ifdef FEAT_GUI_GTK
            gdk_im_end();
#else
            XUnsetICFocus(xic);
#endif
        }
    }
}

    void
im_set_position(row, col)
    int         row UNUSED;
    int         col UNUSED;
{
    xim_set_preedit();
}

/*
 * Set the XIM to the current cursor position.
 */
    void
xim_set_preedit()
{
    if (xic == NULL)
        return;

    xim_set_focus(TRUE);

#ifdef FEAT_GUI_GTK
    if (gdk_im_ready())
    {
        int             attrmask;
        GdkICAttr       *attr;

        if (!xic_attr)
            return;

        attr = xic_attr;
        attrmask = 0;

# ifdef FEAT_XFONTSET
        if ((xim_input_style & (int)GDK_IM_PREEDIT_POSITION)
                && gui.fontset != NOFONTSET
                && gui.fontset->type == GDK_FONT_FONTSET)
        {
            if (!xim_has_focus)
            {
                if (attr->spot_location.y >= 0)
                {
                    attr->spot_location.x = 0;
                    attr->spot_location.y = -100;
                    attrmask |= (int)GDK_IC_SPOT_LOCATION;
                }
            }
            else
            {
                gint    width, height;

                if (attr->spot_location.x != TEXT_X(gui.col)
                    || attr->spot_location.y != TEXT_Y(gui.row))
                {
                    attr->spot_location.x = TEXT_X(gui.col);
                    attr->spot_location.y = TEXT_Y(gui.row);
                    attrmask |= (int)GDK_IC_SPOT_LOCATION;
                }

                gdk_window_get_size(gui.drawarea->window, &width, &height);
                width -= 2 * gui.border_offset;
                height -= 2 * gui.border_offset;
                if (xim_input_style & (int)GDK_IM_STATUS_AREA)
                    height -= gui.char_height;
                if (attr->preedit_area.width != width
                    || attr->preedit_area.height != height)
                {
                    attr->preedit_area.x = gui.border_offset;
                    attr->preedit_area.y = gui.border_offset;
                    attr->preedit_area.width = width;
                    attr->preedit_area.height = height;
                    attrmask |= (int)GDK_IC_PREEDIT_AREA;
                }

                if (attr->preedit_fontset != gui.current_font)
                {
                    attr->preedit_fontset = gui.current_font;
                    attrmask |= (int)GDK_IC_PREEDIT_FONTSET;
                }
            }
        }
# endif /* FEAT_XFONTSET */

        if (xim_fg_color == INVALCOLOR)
        {
            xim_fg_color = gui.def_norm_pixel;
            xim_bg_color = gui.def_back_pixel;
        }
        if (attr->preedit_foreground.pixel != xim_fg_color)
        {
            attr->preedit_foreground.pixel = xim_fg_color;
            attrmask |= (int)GDK_IC_PREEDIT_FOREGROUND;
        }
        if (attr->preedit_background.pixel != xim_bg_color)
        {
            attr->preedit_background.pixel = xim_bg_color;
            attrmask |= (int)GDK_IC_PREEDIT_BACKGROUND;
        }

        if (attrmask != 0)
            gdk_ic_set_attr(xic, attr, (GdkICAttributesType)attrmask);
    }
#else /* FEAT_GUI_GTK */
    {
        XVaNestedList attr_list;
        XRectangle spot_area;
        XPoint over_spot;
        int line_space;

        if (!xim_has_focus)
        {
            /* hide XIM cursor */
            over_spot.x = 0;
            over_spot.y = -100; /* arbitrary invisible position */
            attr_list = (XVaNestedList) XVaCreateNestedList(0,
                                                            XNSpotLocation,
                                                            &over_spot,
                                                            NULL);
            XSetICValues(xic, XNPreeditAttributes, attr_list, NULL);
            XFree(attr_list);
            return;
        }

        if (input_style & XIMPreeditPosition)
        {
            if (xim_fg_color == INVALCOLOR)
            {
                xim_fg_color = gui.def_norm_pixel;
                xim_bg_color = gui.def_back_pixel;
            }
            over_spot.x = TEXT_X(gui.col);
            over_spot.y = TEXT_Y(gui.row);
            spot_area.x = 0;
            spot_area.y = 0;
            spot_area.height = gui.char_height * Rows;
            spot_area.width  = gui.char_width * Columns;
            line_space = gui.char_height;
            attr_list = (XVaNestedList) XVaCreateNestedList(0,
                                            XNSpotLocation, &over_spot,
                                            XNForeground, (Pixel) xim_fg_color,
                                            XNBackground, (Pixel) xim_bg_color,
                                            XNArea, &spot_area,
                                            XNLineSpace, line_space,
                                            NULL);
            if (XSetICValues(xic, XNPreeditAttributes, attr_list, NULL))
                EMSG(_("E284: Cannot set IC values"));
            XFree(attr_list);
        }
    }
#endif /* FEAT_GUI_GTK */
}

/*
 * Set up the status area.
 *
 * This should use a separate Widget, but that seems not possible, because
 * preedit_area and status_area should be set to the same window as for the
 * text input.  Unfortunately this means the status area pollutes the text
 * window...
 */
    void
xim_set_status_area()
{
    if (xic == NULL)
        return;

#ifdef FEAT_GUI_GTK
# if defined(FEAT_XFONTSET)
    if (use_status_area)
    {
        GdkICAttr       *attr;
        int             style;
        gint            width, height;
        GtkWidget       *widget;
        int             attrmask;

        if (!xic_attr)
            return;

        attr = xic_attr;
        attrmask = 0;
        style = (int)gdk_ic_get_style(xic);
        if ((style & (int)GDK_IM_STATUS_MASK) == (int)GDK_IM_STATUS_AREA)
        {
            if (gui.fontset != NOFONTSET
                    && gui.fontset->type == GDK_FONT_FONTSET)
            {
                widget = gui.mainwin;
                gdk_window_get_size(widget->window, &width, &height);

                attrmask |= (int)GDK_IC_STATUS_AREA;
                attr->status_area.x = 0;
                attr->status_area.y = height - gui.char_height - 1;
                attr->status_area.width = width;
                attr->status_area.height = gui.char_height;
            }
        }
        if (attrmask != 0)
            gdk_ic_set_attr(xic, attr, (GdkICAttributesType)attrmask);
    }
# endif
#else
    {
        XVaNestedList preedit_list = 0, status_list = 0, list = 0;
        XRectangle pre_area, status_area;

        if (input_style & XIMStatusArea)
        {
            if (input_style & XIMPreeditArea)
            {
                XRectangle *needed_rect;

                /* to get status_area width */
                status_list = XVaCreateNestedList(0, XNAreaNeeded,
                                                  &needed_rect, NULL);
                XGetICValues(xic, XNStatusAttributes, status_list, NULL);
                XFree(status_list);

                status_area.width = needed_rect->width;
            }
            else
                status_area.width = gui.char_width * Columns;

            status_area.x = 0;
            status_area.y = gui.char_height * Rows + gui.border_offset;
            if (gui.which_scrollbars[SBAR_BOTTOM])
                status_area.y += gui.scrollbar_height;
#ifdef FEAT_MENU
            if (gui.menu_is_active)
                status_area.y += gui.menu_height;
#endif
            status_area.height = gui.char_height;
            status_list = XVaCreateNestedList(0, XNArea, &status_area, NULL);
        }
        else
        {
            status_area.x = 0;
            status_area.y = gui.char_height * Rows + gui.border_offset;
            if (gui.which_scrollbars[SBAR_BOTTOM])
                status_area.y += gui.scrollbar_height;
#ifdef FEAT_MENU
            if (gui.menu_is_active)
                status_area.y += gui.menu_height;
#endif
            status_area.width = 0;
            status_area.height = gui.char_height;
        }

        if (input_style & XIMPreeditArea)   /* off-the-spot */
        {
            pre_area.x = status_area.x + status_area.width;
            pre_area.y = gui.char_height * Rows + gui.border_offset;
            pre_area.width = gui.char_width * Columns - pre_area.x;
            if (gui.which_scrollbars[SBAR_BOTTOM])
                pre_area.y += gui.scrollbar_height;
#ifdef FEAT_MENU
            if (gui.menu_is_active)
                pre_area.y += gui.menu_height;
#endif
            pre_area.height = gui.char_height;
            preedit_list = XVaCreateNestedList(0, XNArea, &pre_area, NULL);
        }
        else if (input_style & XIMPreeditPosition)   /* over-the-spot */
        {
            pre_area.x = 0;
            pre_area.y = 0;
            pre_area.height = gui.char_height * Rows;
            pre_area.width = gui.char_width * Columns;
            preedit_list = XVaCreateNestedList(0, XNArea, &pre_area, NULL);
        }

        if (preedit_list && status_list)
            list = XVaCreateNestedList(0, XNPreeditAttributes, preedit_list,
                                       XNStatusAttributes, status_list, NULL);
        else if (preedit_list)
            list = XVaCreateNestedList(0, XNPreeditAttributes, preedit_list,
                                       NULL);
        else if (status_list)
            list = XVaCreateNestedList(0, XNStatusAttributes, status_list,
                                       NULL);
        else
            list = NULL;

        if (list)
        {
            XSetICValues(xic, XNVaNestedList, list, NULL);
            XFree(list);
        }
        if (status_list)
            XFree(status_list);
        if (preedit_list)
            XFree(preedit_list);
    }
#endif
}

#if defined(FEAT_GUI_X11) || defined(FEAT_GUI_GTK)
static char e_xim[] = N_("E285: Failed to create input context");
#endif

#if defined(FEAT_GUI_X11) || defined(PROTO)
# if defined(XtSpecificationRelease) && XtSpecificationRelease >= 6 && !defined(sun)
#  define USE_X11R6_XIM
# endif

static int xim_real_init __ARGS((Window x11_window, Display *x11_display));


#ifdef USE_X11R6_XIM
static void xim_instantiate_cb __ARGS((Display *display, XPointer client_data, XPointer call_data));
static void xim_destroy_cb __ARGS((XIM im, XPointer client_data, XPointer call_data));

    static void
xim_instantiate_cb(display, client_data, call_data)
    Display     *display;
    XPointer    client_data UNUSED;
    XPointer    call_data UNUSED;
{
    Window      x11_window;
    Display     *x11_display;

#ifdef XIM_DEBUG
    xim_log("xim_instantiate_cb()\n");
#endif

    gui_get_x11_windis(&x11_window, &x11_display);
    if (display != x11_display)
        return;

    xim_real_init(x11_window, x11_display);
    gui_set_shellsize(FALSE, FALSE, RESIZE_BOTH);
    if (xic != NULL)
        XUnregisterIMInstantiateCallback(x11_display, NULL, NULL, NULL,
                                         xim_instantiate_cb, NULL);
}

    static void
xim_destroy_cb(im, client_data, call_data)
    XIM         im UNUSED;
    XPointer    client_data UNUSED;
    XPointer    call_data UNUSED;
{
    Window      x11_window;
    Display     *x11_display;

#ifdef XIM_DEBUG
    xim_log("xim_destroy_cb()\n");
#endif
    gui_get_x11_windis(&x11_window, &x11_display);

    xic = NULL;
    status_area_enabled = FALSE;

    gui_set_shellsize(FALSE, FALSE, RESIZE_BOTH);

    XRegisterIMInstantiateCallback(x11_display, NULL, NULL, NULL,
                                   xim_instantiate_cb, NULL);
}
#endif

    void
xim_init()
{
    Window      x11_window;
    Display     *x11_display;

#ifdef XIM_DEBUG
    xim_log("xim_init()\n");
#endif

    gui_get_x11_windis(&x11_window, &x11_display);

    xic = NULL;

    if (xim_real_init(x11_window, x11_display))
        return;

    gui_set_shellsize(FALSE, FALSE, RESIZE_BOTH);

#ifdef USE_X11R6_XIM
    XRegisterIMInstantiateCallback(x11_display, NULL, NULL, NULL,
                                   xim_instantiate_cb, NULL);
#endif
}

    static int
xim_real_init(x11_window, x11_display)
    Window      x11_window;
    Display     *x11_display;
{
    int         i;
    char        *p,
                *s,
                *ns,
                *end,
                tmp[1024];
#define IMLEN_MAX 40
    char        buf[IMLEN_MAX + 7];
    XIM         xim = NULL;
    XIMStyles   *xim_styles;
    XIMStyle    this_input_style = 0;
    Boolean     found;
    XPoint      over_spot;
    XVaNestedList preedit_list, status_list;

    input_style = 0;
    status_area_enabled = FALSE;

    if (xic != NULL)
        return FALSE;

    if (gui.rsrc_input_method != NULL && *gui.rsrc_input_method != NUL)
    {
        strcpy(tmp, gui.rsrc_input_method);
        for (ns = s = tmp; ns != NULL && *s != NUL;)
        {
            s = (char *)skipwhite((char_u *)s);
            if (*s == NUL)
                break;
            if ((ns = end = strchr(s, ',')) == NULL)
                end = s + strlen(s);
            while (isspace(((char_u *)end)[-1]))
                end--;
            *end = NUL;

            if (strlen(s) <= IMLEN_MAX)
            {
                strcpy(buf, "@im=");
                strcat(buf, s);
                if ((p = XSetLocaleModifiers(buf)) != NULL && *p != NUL
                        && (xim = XOpenIM(x11_display, NULL, NULL, NULL))
                                                                      != NULL)
                    break;
            }

            s = ns + 1;
        }
    }

    if (xim == NULL && (p = XSetLocaleModifiers("")) != NULL && *p != NUL)
        xim = XOpenIM(x11_display, NULL, NULL, NULL);

    /* This is supposed to be useful to obtain characters through
     * XmbLookupString() without really using a XIM. */
    if (xim == NULL && (p = XSetLocaleModifiers("@im=none")) != NULL
                                                                 && *p != NUL)
        xim = XOpenIM(x11_display, NULL, NULL, NULL);

    if (xim == NULL)
    {
        /* Only give this message when verbose is set, because too many people
         * got this message when they didn't want to use a XIM. */
        if (p_verbose > 0)
        {
            verbose_enter();
            EMSG(_("E286: Failed to open input method"));
            verbose_leave();
        }
        return FALSE;
    }

#ifdef USE_X11R6_XIM
    {
        XIMCallback destroy_cb;

        destroy_cb.callback = xim_destroy_cb;
        destroy_cb.client_data = NULL;
        if (XSetIMValues(xim, XNDestroyCallback, &destroy_cb, NULL))
            EMSG(_("E287: Warning: Could not set destroy callback to IM"));
    }
#endif

    if (XGetIMValues(xim, XNQueryInputStyle, &xim_styles, NULL) || !xim_styles)
    {
        EMSG(_("E288: input method doesn't support any style"));
        XCloseIM(xim);
        return FALSE;
    }

    found = False;
    strcpy(tmp, gui.rsrc_preedit_type_name);
    for (s = tmp; s && !found; )
    {
        while (*s && isspace((unsigned char)*s))
            s++;
        if (!*s)
            break;
        if ((ns = end = strchr(s, ',')) != 0)
            ns++;
        else
            end = s + strlen(s);
        while (isspace((unsigned char)*end))
            end--;
        *end = '\0';

        if (!strcmp(s, "OverTheSpot"))
            this_input_style = (XIMPreeditPosition | XIMStatusArea);
        else if (!strcmp(s, "OffTheSpot"))
            this_input_style = (XIMPreeditArea | XIMStatusArea);
        else if (!strcmp(s, "Root"))
            this_input_style = (XIMPreeditNothing | XIMStatusNothing);

        for (i = 0; (unsigned short)i < xim_styles->count_styles; i++)
        {
            if (this_input_style == xim_styles->supported_styles[i])
            {
                found = True;
                break;
            }
        }
        if (!found)
            for (i = 0; (unsigned short)i < xim_styles->count_styles; i++)
            {
                if ((xim_styles->supported_styles[i] & this_input_style)
                        == (this_input_style & ~XIMStatusArea))
                {
                    this_input_style &= ~XIMStatusArea;
                    found = True;
                    break;
                }
            }

        s = ns;
    }
    XFree(xim_styles);

    if (!found)
    {
        /* Only give this message when verbose is set, because too many people
         * got this message when they didn't want to use a XIM. */
        if (p_verbose > 0)
        {
            verbose_enter();
            EMSG(_("E289: input method doesn't support my preedit type"));
            verbose_leave();
        }
        XCloseIM(xim);
        return FALSE;
    }

    over_spot.x = TEXT_X(gui.col);
    over_spot.y = TEXT_Y(gui.row);
    input_style = this_input_style;

    /* A crash was reported when trying to pass gui.norm_font as XNFontSet,
     * thus that has been removed.  Hopefully the default works... */
#ifdef FEAT_XFONTSET
    if (gui.fontset != NOFONTSET)
    {
        preedit_list = XVaCreateNestedList(0,
                                XNSpotLocation, &over_spot,
                                XNForeground, (Pixel)gui.def_norm_pixel,
                                XNBackground, (Pixel)gui.def_back_pixel,
                                XNFontSet, (XFontSet)gui.fontset,
                                NULL);
        status_list = XVaCreateNestedList(0,
                                XNForeground, (Pixel)gui.def_norm_pixel,
                                XNBackground, (Pixel)gui.def_back_pixel,
                                XNFontSet, (XFontSet)gui.fontset,
                                NULL);
    }
    else
#endif
    {
        preedit_list = XVaCreateNestedList(0,
                                XNSpotLocation, &over_spot,
                                XNForeground, (Pixel)gui.def_norm_pixel,
                                XNBackground, (Pixel)gui.def_back_pixel,
                                NULL);
        status_list = XVaCreateNestedList(0,
                                XNForeground, (Pixel)gui.def_norm_pixel,
                                XNBackground, (Pixel)gui.def_back_pixel,
                                NULL);
    }

    xic = XCreateIC(xim,
                    XNInputStyle, input_style,
                    XNClientWindow, x11_window,
                    XNFocusWindow, gui.wid,
                    XNPreeditAttributes, preedit_list,
                    XNStatusAttributes, status_list,
                    NULL);
    XFree(status_list);
    XFree(preedit_list);
    if (xic != NULL)
    {
        if (input_style & XIMStatusArea)
        {
            xim_set_status_area();
            status_area_enabled = TRUE;
        }
        else
            gui_set_shellsize(FALSE, FALSE, RESIZE_BOTH);
    }
    else
    {
        EMSG(_(e_xim));
        XCloseIM(xim);
        return FALSE;
    }

    return TRUE;
}

#endif /* FEAT_GUI_X11 */

#if defined(FEAT_GUI_GTK) || defined(PROTO)

# ifdef FEAT_XFONTSET
static char e_overthespot[] = N_("E290: over-the-spot style requires fontset");
# endif

# ifdef PROTO
typedef int GdkIC;
# endif

    void
xim_decide_input_style()
{
    /* GDK_IM_STATUS_CALLBACKS was disabled, enabled it to allow Japanese
     * OverTheSpot. */
    int supported_style = (int)GDK_IM_PREEDIT_NONE |
                                 (int)GDK_IM_PREEDIT_NOTHING |
                                 (int)GDK_IM_PREEDIT_POSITION |
                                 (int)GDK_IM_PREEDIT_CALLBACKS |
                                 (int)GDK_IM_STATUS_CALLBACKS |
                                 (int)GDK_IM_STATUS_AREA |
                                 (int)GDK_IM_STATUS_NONE |
                                 (int)GDK_IM_STATUS_NOTHING;

#ifdef XIM_DEBUG
    xim_log("xim_decide_input_style()\n");
#endif

    if (!gdk_im_ready())
        xim_input_style = 0;
    else
    {
        if (gtk_major_version > 1
                || (gtk_major_version == 1
                    && (gtk_minor_version > 2
                        || (gtk_minor_version == 2 && gtk_micro_version >= 3))))
            use_status_area = TRUE;
        else
        {
            EMSG(_("E291: Your GTK+ is older than 1.2.3. Status area disabled"));
            use_status_area = FALSE;
        }
#ifdef FEAT_XFONTSET
        if (gui.fontset == NOFONTSET || gui.fontset->type != GDK_FONT_FONTSET)
#endif
            supported_style &= ~((int)GDK_IM_PREEDIT_POSITION
                                                   | (int)GDK_IM_STATUS_AREA);
        if (!use_status_area)
            supported_style &= ~(int)GDK_IM_STATUS_AREA;
        xim_input_style = (int)gdk_im_decide_style((GdkIMStyle)supported_style);
    }
}

    static void
preedit_start_cbproc(XIC thexic UNUSED,
                     XPointer client_data UNUSED,
                     XPointer call_data UNUSED)
{
#ifdef XIM_DEBUG
    xim_log("xim_decide_input_style()\n");
#endif

    draw_feedback = NULL;
    xim_can_preediting = TRUE;
    xim_has_preediting = TRUE;
    gui_update_cursor(TRUE, FALSE);
    if (showmode() > 0)
    {
        setcursor();
        out_flush();
    }
}

    static void
xim_back_delete(int n)
{
    char_u str[3];

    str[0] = CSI;
    str[1] = 'k';
    str[2] = 'b';
    while (n-- > 0)
        add_to_input_buf(str, 3);
}

static GSList *key_press_event_queue = NULL;
static gboolean processing_queued_event = FALSE;

    static void
preedit_draw_cbproc(XIC thexic UNUSED,
                    XPointer client_data UNUSED,
                    XPointer call_data)
{
    XIMPreeditDrawCallbackStruct *draw_data;
    XIMText     *text;
    char        *src;
    GSList      *event_queue;

#ifdef XIM_DEBUG
    xim_log("preedit_draw_cbproc()\n");
#endif

    draw_data = (XIMPreeditDrawCallbackStruct *) call_data;
    text = (XIMText *) draw_data->text;

    if ((text == NULL && draw_data->chg_length == preedit_buf_len)
                                                      || preedit_buf_len == 0)
    {
        init_preedit_start_col();
        vim_free(draw_feedback);
        draw_feedback = NULL;
    }
    if (draw_data->chg_length > 0)
    {
        int bs_cnt;

        if (draw_data->chg_length > preedit_buf_len)
            bs_cnt = preedit_buf_len;
        else
            bs_cnt = draw_data->chg_length;
        xim_back_delete(bs_cnt);
        preedit_buf_len -= bs_cnt;
    }
    if (text != NULL)
    {
        int             len;
#ifdef FEAT_MBYTE
        char_u          *buf = NULL;
        unsigned int    nfeedback = 0;
#endif
        char_u          *ptr;

        src = text->string.multi_byte;
        if (src != NULL && !text->encoding_is_wchar)
        {
            len = strlen(src);
            ptr = (char_u *)src;
            /* Avoid the enter for decision */
            if (*ptr == '\n')
                return;

#ifdef FEAT_MBYTE
            if (input_conv.vc_type != CONV_NONE
                    && (buf = string_convert(&input_conv,
                                                 (char_u *)src, &len)) != NULL)
            {
                /* Converted from 'termencoding' to 'encoding'. */
                add_to_input_buf_csi(buf, len);
                ptr = buf;
            }
            else
#endif
                add_to_input_buf_csi((char_u *)src, len);
            /* Add count of character to preedit_buf_len  */
            while (*ptr != NUL)
            {
#ifdef FEAT_MBYTE
                if (draw_data->text->feedback != NULL)
                {
                    if (draw_feedback == NULL)
                        draw_feedback = (char *)alloc(draw_data->chg_first
                                                              + text->length);
                    else
                        draw_feedback = vim_realloc(draw_feedback,
                                         draw_data->chg_first + text->length);
                    if (draw_feedback != NULL)
                    {
                        draw_feedback[nfeedback + draw_data->chg_first]
                                       = draw_data->text->feedback[nfeedback];
                        nfeedback++;
                    }
                }
                if (has_mbyte)
                    ptr += (*mb_ptr2len)(ptr);
                else
#endif
                    ptr++;
                preedit_buf_len++;
            }
#ifdef FEAT_MBYTE
            vim_free(buf);
#endif
            preedit_end_col = MAXCOL;
        }
    }
    if (text != NULL || draw_data->chg_length > 0)
    {
        event_queue = key_press_event_queue;
        processing_queued_event = TRUE;
        while (event_queue != NULL && processing_queued_event)
        {
            GdkEvent *ev = event_queue->data;

            gboolean *ret;
            gtk_signal_emit_by_name((GtkObject*)gui.mainwin, "key_press_event",
                                                                    ev, &ret);
            gdk_event_free(ev);
            event_queue = event_queue->next;
        }
        processing_queued_event = FALSE;
        if (key_press_event_queue)
        {
            g_slist_free(key_press_event_queue);
            key_press_event_queue = NULL;
        }
    }
    if (gtk_main_level() > 0)
        gtk_main_quit();
}

/*
 * Retrieve the highlighting attributes at column col in the preedit string.
 * Return -1 if not in preediting mode or if col is out of range.
 */
    int
im_get_feedback_attr(int col)
{
    if (draw_feedback != NULL && col < preedit_buf_len)
    {
        if (draw_feedback[col] & XIMReverse)
            return HL_INVERSE;
        else if (draw_feedback[col] & XIMUnderline)
            return HL_UNDERLINE;
        else
            return hl_attr(HLF_V);
    }

    return -1;
}

    static void
preedit_caret_cbproc(XIC thexic UNUSED,
                     XPointer client_data UNUSED,
                     XPointer call_data UNUSED)
{
#ifdef XIM_DEBUG
    xim_log("preedit_caret_cbproc()\n");
#endif
}

    static void
preedit_done_cbproc(XIC thexic UNUSED,
                    XPointer client_data UNUSED,
                    XPointer call_data UNUSED)
{
#ifdef XIM_DEBUG
    xim_log("preedit_done_cbproc()\n");
#endif

    vim_free(draw_feedback);
    draw_feedback = NULL;
    xim_can_preediting = FALSE;
    xim_has_preediting = FALSE;
    gui_update_cursor(TRUE, FALSE);
    if (showmode() > 0)
    {
        setcursor();
        out_flush();
    }
}

    void
xim_reset(void)
{
    char *text;

#ifdef XIM_DEBUG
    xim_log("xim_reset()\n");
#endif

    if (xic != NULL)
    {
        text = XmbResetIC(((GdkICPrivate *)xic)->xic);
        if (text != NULL && !(xim_input_style & (int)GDK_IM_PREEDIT_CALLBACKS))
            add_to_input_buf_csi((char_u *)text, strlen(text));
        else
            preedit_buf_len = 0;
        if (text != NULL)
            XFree(text);
    }
}

    int
xim_queue_key_press_event(GdkEventKey *event, int down UNUSED)
{
#ifdef XIM_DEBUG
    xim_log("xim_queue_key_press_event()\n");
#endif

    if (preedit_buf_len <= 0)
        return FALSE;
    if (processing_queued_event)
        processing_queued_event = FALSE;

    key_press_event_queue = g_slist_append(key_press_event_queue,
                                           gdk_event_copy((GdkEvent *)event));
    return TRUE;
}

    static void
preedit_callback_setup(GdkIC *ic UNUSED)
{
    XIC xxic;
    XVaNestedList preedit_attr;
    XIMCallback preedit_start_cb;
    XIMCallback preedit_draw_cb;
    XIMCallback preedit_caret_cb;
    XIMCallback preedit_done_cb;

    xxic = ((GdkICPrivate*)xic)->xic;
    preedit_start_cb.callback = (XIMProc)preedit_start_cbproc;
    preedit_draw_cb.callback = (XIMProc)preedit_draw_cbproc;
    preedit_caret_cb.callback = (XIMProc)preedit_caret_cbproc;
    preedit_done_cb.callback = (XIMProc)preedit_done_cbproc;
    preedit_attr
         = XVaCreateNestedList(0,
                               XNPreeditStartCallback, &preedit_start_cb,
                               XNPreeditDrawCallback, &preedit_draw_cb,
                               XNPreeditCaretCallback, &preedit_caret_cb,
                               XNPreeditDoneCallback, &preedit_done_cb,
                               NULL);
    XSetICValues(xxic, XNPreeditAttributes, preedit_attr, NULL);
    XFree(preedit_attr);
}

    static void
reset_state_setup(GdkIC *ic UNUSED)
{
#ifdef USE_X11R6_XIM
    /* don't change the input context when we call reset */
    XSetICValues(((GdkICPrivate *)ic)->xic, XNResetState, XIMPreserveState,
                                                                        NULL);
#endif
}

    void
xim_init(void)
{
#ifdef XIM_DEBUG
    xim_log("xim_init()\n");
#endif

    xic = NULL;
    xic_attr = NULL;

    if (!gdk_im_ready())
    {
        if (p_verbose > 0)
        {
            verbose_enter();
            EMSG(_("E292: Input Method Server is not running"));
            verbose_leave();
        }
        return;
    }
    if ((xic_attr = gdk_ic_attr_new()) != NULL)
    {
#ifdef FEAT_XFONTSET
        gint width, height;
#endif
        int             mask;
        GdkColormap     *colormap;
        GdkICAttr       *attr = xic_attr;
        int             attrmask = (int)GDK_IC_ALL_REQ;
        GtkWidget       *widget = gui.drawarea;

        attr->style = (GdkIMStyle)xim_input_style;
        attr->client_window = gui.mainwin->window;

        if ((colormap = gtk_widget_get_colormap(widget)) !=
            gtk_widget_get_default_colormap())
        {
            attrmask |= (int)GDK_IC_PREEDIT_COLORMAP;
            attr->preedit_colormap = colormap;
        }
        attrmask |= (int)GDK_IC_PREEDIT_FOREGROUND;
        attrmask |= (int)GDK_IC_PREEDIT_BACKGROUND;
        attr->preedit_foreground = widget->style->fg[GTK_STATE_NORMAL];
        attr->preedit_background = widget->style->base[GTK_STATE_NORMAL];

#ifdef FEAT_XFONTSET
        if ((xim_input_style & (int)GDK_IM_PREEDIT_MASK)
                                              == (int)GDK_IM_PREEDIT_POSITION)
        {
            if (gui.fontset == NOFONTSET
                    || gui.fontset->type != GDK_FONT_FONTSET)
            {
                EMSG(_(e_overthespot));
            }
            else
            {
                gdk_window_get_size(widget->window, &width, &height);

                attrmask |= (int)GDK_IC_PREEDIT_POSITION_REQ;
                attr->spot_location.x = TEXT_X(0);
                attr->spot_location.y = TEXT_Y(0);
                attr->preedit_area.x = gui.border_offset;
                attr->preedit_area.y = gui.border_offset;
                attr->preedit_area.width = width - 2*gui.border_offset;
                attr->preedit_area.height = height - 2*gui.border_offset;
                attr->preedit_fontset = gui.fontset;
            }
        }

        if ((xim_input_style & (int)GDK_IM_STATUS_MASK)
                                                   == (int)GDK_IM_STATUS_AREA)
        {
            if (gui.fontset == NOFONTSET
                    || gui.fontset->type != GDK_FONT_FONTSET)
            {
                EMSG(_(e_overthespot));
            }
            else
            {
                gdk_window_get_size(gui.mainwin->window, &width, &height);
                attrmask |= (int)GDK_IC_STATUS_AREA_REQ;
                attr->status_area.x = 0;
                attr->status_area.y = height - gui.char_height - 1;
                attr->status_area.width = width;
                attr->status_area.height = gui.char_height;
                attr->status_fontset = gui.fontset;
            }
        }
        else if ((xim_input_style & (int)GDK_IM_STATUS_MASK)
                                              == (int)GDK_IM_STATUS_CALLBACKS)
        {
            /* FIXME */
        }
#endif

        xic = gdk_ic_new(attr, (GdkICAttributesType)attrmask);

        if (xic == NULL)
            EMSG(_(e_xim));
        else
        {
            mask = (int)gdk_window_get_events(widget->window);
            mask |= (int)gdk_ic_get_events(xic);
            gdk_window_set_events(widget->window, (GdkEventMask)mask);
            if (xim_input_style & (int)GDK_IM_PREEDIT_CALLBACKS)
                preedit_callback_setup(xic);
            reset_state_setup(xic);
        }
    }
}

    void
im_shutdown(void)
{
#ifdef XIM_DEBUG
    xim_log("im_shutdown()\n");
#endif

    if (xic != NULL)
    {
        gdk_im_end();
        gdk_ic_destroy(xic);
        xic = NULL;
    }
    xim_is_active = FALSE;
    xim_can_preediting = FALSE;
    preedit_start_col = MAXCOL;
    xim_has_preediting = FALSE;
}

#endif /* FEAT_GUI_GTK */

    int
xim_get_status_area_height()
{
#ifdef FEAT_GUI_GTK
    if (xim_input_style & (int)GDK_IM_STATUS_AREA)
        return gui.char_height;
#else
    if (status_area_enabled)
        return gui.char_height;
#endif
    return 0;
}

/*
 * Get IM status.  When IM is on, return TRUE.  Else return FALSE.
 * FIXME: This doesn't work correctly: Having focus doesn't always mean XIM is
 * active, when not having focus XIM may still be active (e.g., when using a
 * tear-off menu item).
 */
    int
im_get_status()
{
#  ifdef FEAT_GUI_GTK
    if (xim_input_style & (int)GDK_IM_PREEDIT_CALLBACKS)
        return xim_can_preediting;
#  endif
    return xim_has_focus;
}

# endif /* !HAVE_GTK2 */

# if (defined(HAVE_GTK2) || defined(FEAT_GUI_MACVIM)) || defined(PROTO)
    int
preedit_get_status(void)
{
    return preedit_is_active;
}
# endif

# if (defined(FEAT_GUI_GTK) || defined(FEAT_GUI_MACVIM)) || defined(PROTO)
    int
im_is_preediting()
{
    return xim_has_preediting;
}
# endif
#endif /* FEAT_XIM */

#if defined(FEAT_MBYTE) || defined(PROTO)

/*
 * Setup "vcp" for conversion from "from" to "to".
 * The names must have been made canonical with enc_canonize().
 * vcp->vc_type must have been initialized to CONV_NONE.
 * Note: cannot be used for conversion from/to ucs-2 and ucs-4 (will use utf-8
 * instead).
 * Afterwards invoke with "from" and "to" equal to NULL to cleanup.
 * Return FAIL when conversion is not supported, OK otherwise.
 */
    int
convert_setup(vcp, from, to)
    vimconv_T   *vcp;
    char_u      *from;
    char_u      *to;
{
    return convert_setup_ext(vcp, from, TRUE, to, TRUE);
}

/*
 * As convert_setup(), but only when from_unicode_is_utf8 is TRUE will all
 * "from" unicode charsets be considered utf-8.  Same for "to".
 */
    int
convert_setup_ext(vcp, from, from_unicode_is_utf8, to, to_unicode_is_utf8)
    vimconv_T   *vcp;
    char_u      *from;
    int         from_unicode_is_utf8;
    char_u      *to;
    int         to_unicode_is_utf8;
{
    int         from_prop;
    int         to_prop;
    int         from_is_utf8;
    int         to_is_utf8;

    /* Reset to no conversion. */
# ifdef USE_ICONV
    if (vcp->vc_type == CONV_ICONV && vcp->vc_fd != (iconv_t)-1)
        iconv_close(vcp->vc_fd);
# endif
    vcp->vc_type = CONV_NONE;
    vcp->vc_factor = 1;
    vcp->vc_fail = FALSE;

    /* No conversion when one of the names is empty or they are equal. */
    if (from == NULL || *from == NUL || to == NULL || *to == NUL
                                                     || STRCMP(from, to) == 0)
        return OK;

    from_prop = enc_canon_props(from);
    to_prop = enc_canon_props(to);
    if (from_unicode_is_utf8)
        from_is_utf8 = from_prop & ENC_UNICODE;
    else
        from_is_utf8 = from_prop == ENC_UNICODE;
    if (to_unicode_is_utf8)
        to_is_utf8 = to_prop & ENC_UNICODE;
    else
        to_is_utf8 = to_prop == ENC_UNICODE;

    if ((from_prop & ENC_LATIN1) && to_is_utf8)
    {
        /* Internal latin1 -> utf-8 conversion. */
        vcp->vc_type = CONV_TO_UTF8;
        vcp->vc_factor = 2;     /* up to twice as long */
    }
    else if ((from_prop & ENC_LATIN9) && to_is_utf8)
    {
        /* Internal latin9 -> utf-8 conversion. */
        vcp->vc_type = CONV_9_TO_UTF8;
        vcp->vc_factor = 3;     /* up to three as long (euro sign) */
    }
    else if (from_is_utf8 && (to_prop & ENC_LATIN1))
    {
        /* Internal utf-8 -> latin1 conversion. */
        vcp->vc_type = CONV_TO_LATIN1;
    }
    else if (from_is_utf8 && (to_prop & ENC_LATIN9))
    {
        /* Internal utf-8 -> latin9 conversion. */
        vcp->vc_type = CONV_TO_LATIN9;
    }
#ifdef WIN3264
    /* Win32-specific codepage <-> codepage conversion without iconv. */
    else if ((from_is_utf8 || encname2codepage(from) > 0)
            && (to_is_utf8 || encname2codepage(to) > 0))
    {
        vcp->vc_type = CONV_CODEPAGE;
        vcp->vc_factor = 2;     /* up to twice as long */
        vcp->vc_cpfrom = from_is_utf8 ? 0 : encname2codepage(from);
        vcp->vc_cpto = to_is_utf8 ? 0 : encname2codepage(to);
    }
#endif
#ifdef MACOS_X
    else if ((from_prop & ENC_MACROMAN) && (to_prop & ENC_LATIN1))
    {
        vcp->vc_type = CONV_MAC_LATIN1;
    }
    else if ((from_prop & ENC_MACROMAN) && to_is_utf8)
    {
        vcp->vc_type = CONV_MAC_UTF8;
        vcp->vc_factor = 2;     /* up to twice as long */
    }
    else if ((from_prop & ENC_LATIN1) && (to_prop & ENC_MACROMAN))
    {
        vcp->vc_type = CONV_LATIN1_MAC;
    }
    else if (from_is_utf8 && (to_prop & ENC_MACROMAN))
    {
        vcp->vc_type = CONV_UTF8_MAC;
    }
#endif
# ifdef USE_ICONV
    else
    {
        /* Use iconv() for conversion. */
        vcp->vc_fd = (iconv_t)my_iconv_open(
                to_is_utf8 ? (char_u *)"utf-8" : to,
                from_is_utf8 ? (char_u *)"utf-8" : from);
        if (vcp->vc_fd != (iconv_t)-1)
        {
            vcp->vc_type = CONV_ICONV;
            vcp->vc_factor = 4; /* could be longer too... */
        }
    }
# endif
    if (vcp->vc_type == CONV_NONE)
        return FAIL;

    return OK;
}

#if defined(FEAT_GUI) || defined(AMIGA) || defined(WIN3264) \
        || defined(MSDOS) || defined(PROTO)
/*
 * Do conversion on typed input characters in-place.
 * The input and output are not NUL terminated!
 * Returns the length after conversion.
 */
    int
convert_input(ptr, len, maxlen)
    char_u      *ptr;
    int         len;
    int         maxlen;
{
    return convert_input_safe(ptr, len, maxlen, NULL, NULL);
}
#endif

/*
 * Like convert_input(), but when there is an incomplete byte sequence at the
 * end return that as an allocated string in "restp" and set "*restlenp" to
 * the length.  If "restp" is NULL it is not used.
 */
    int
convert_input_safe(ptr, len, maxlen, restp, restlenp)
    char_u      *ptr;
    int         len;
    int         maxlen;
    char_u      **restp;
    int         *restlenp;
{
    char_u      *d;
    int         dlen = len;
    int         unconvertlen = 0;

    d = string_convert_ext(&input_conv, ptr, &dlen,
                                        restp == NULL ? NULL : &unconvertlen);
    if (d != NULL)
    {
        if (dlen <= maxlen)
        {
            if (unconvertlen > 0)
            {
                /* Move the unconverted characters to allocated memory. */
                *restp = alloc(unconvertlen);
                if (*restp != NULL)
                    mch_memmove(*restp, ptr + len - unconvertlen, unconvertlen);
                *restlenp = unconvertlen;
            }
            mch_memmove(ptr, d, dlen);
        }
        else
            /* result is too long, keep the unconverted text (the caller must
             * have done something wrong!) */
            dlen = len;
        vim_free(d);
    }
    return dlen;
}

/*
 * Convert text "ptr[*lenp]" according to "vcp".
 * Returns the result in allocated memory and sets "*lenp".
 * When "lenp" is NULL, use NUL terminated strings.
 * Illegal chars are often changed to "?", unless vcp->vc_fail is set.
 * When something goes wrong, NULL is returned and "*lenp" is unchanged.
 */
    char_u *
string_convert(vcp, ptr, lenp)
    vimconv_T   *vcp;
    char_u      *ptr;
    int         *lenp;
{
    return string_convert_ext(vcp, ptr, lenp, NULL);
}

/*
 * Like string_convert(), but when "unconvlenp" is not NULL and there are is
 * an incomplete sequence at the end it is not converted and "*unconvlenp" is
 * set to the number of remaining bytes.
 */
    char_u *
string_convert_ext(vcp, ptr, lenp, unconvlenp)
    vimconv_T   *vcp;
    char_u      *ptr;
    int         *lenp;
    int         *unconvlenp;
{
    char_u      *retval = NULL;
    char_u      *d;
    int         len;
    int         i;
    int         l;
    int         c;

    if (lenp == NULL)
        len = (int)STRLEN(ptr);
    else
        len = *lenp;
    if (len == 0)
        return vim_strsave((char_u *)"");

    switch (vcp->vc_type)
    {
        case CONV_TO_UTF8:      /* latin1 to utf-8 conversion */
            retval = alloc(len * 2 + 1);
            if (retval == NULL)
                break;
            d = retval;
            for (i = 0; i < len; ++i)
            {
                c = ptr[i];
                if (c < 0x80)
                    *d++ = c;
                else
                {
                    *d++ = 0xc0 + ((unsigned)c >> 6);
                    *d++ = 0x80 + (c & 0x3f);
                }
            }
            *d = NUL;
            if (lenp != NULL)
                *lenp = (int)(d - retval);
            break;

        case CONV_9_TO_UTF8:    /* latin9 to utf-8 conversion */
            retval = alloc(len * 3 + 1);
            if (retval == NULL)
                break;
            d = retval;
            for (i = 0; i < len; ++i)
            {
                c = ptr[i];
                switch (c)
                {
                    case 0xa4: c = 0x20ac; break;   /* euro */
                    case 0xa6: c = 0x0160; break;   /* S hat */
                    case 0xa8: c = 0x0161; break;   /* S -hat */
                    case 0xb4: c = 0x017d; break;   /* Z hat */
                    case 0xb8: c = 0x017e; break;   /* Z -hat */
                    case 0xbc: c = 0x0152; break;   /* OE */
                    case 0xbd: c = 0x0153; break;   /* oe */
                    case 0xbe: c = 0x0178; break;   /* Y */
                }
                d += utf_char2bytes(c, d);
            }
            *d = NUL;
            if (lenp != NULL)
                *lenp = (int)(d - retval);
            break;

        case CONV_TO_LATIN1:    /* utf-8 to latin1 conversion */
        case CONV_TO_LATIN9:    /* utf-8 to latin9 conversion */
            retval = alloc(len + 1);
            if (retval == NULL)
                break;
            d = retval;
            for (i = 0; i < len; ++i)
            {
                l = utf_ptr2len_len(ptr + i, len - i);
                if (l == 0)
                    *d++ = NUL;
                else if (l == 1)
                {
                    int l_w = utf8len_tab_zero[ptr[i]];

                    if (l_w == 0)
                    {
                        /* Illegal utf-8 byte cannot be converted */
                        vim_free(retval);
                        return NULL;
                    }
                    if (unconvlenp != NULL && l_w > len - i)
                    {
                        /* Incomplete sequence at the end. */
                        *unconvlenp = len - i;
                        break;
                    }
                    *d++ = ptr[i];
                }
                else
                {
                    c = utf_ptr2char(ptr + i);
                    if (vcp->vc_type == CONV_TO_LATIN9)
                        switch (c)
                        {
                            case 0x20ac: c = 0xa4; break;   /* euro */
                            case 0x0160: c = 0xa6; break;   /* S hat */
                            case 0x0161: c = 0xa8; break;   /* S -hat */
                            case 0x017d: c = 0xb4; break;   /* Z hat */
                            case 0x017e: c = 0xb8; break;   /* Z -hat */
                            case 0x0152: c = 0xbc; break;   /* OE */
                            case 0x0153: c = 0xbd; break;   /* oe */
                            case 0x0178: c = 0xbe; break;   /* Y */
                            case 0xa4:
                            case 0xa6:
                            case 0xa8:
                            case 0xb4:
                            case 0xb8:
                            case 0xbc:
                            case 0xbd:
                            case 0xbe: c = 0x100; break; /* not in latin9 */
                        }
                    if (!utf_iscomposing(c))    /* skip composing chars */
                    {
                        if (c < 0x100)
                            *d++ = c;
                        else if (vcp->vc_fail)
                        {
                            vim_free(retval);
                            return NULL;
                        }
                        else
                        {
                            *d++ = 0xbf;
                            if (utf_char2cells(c) > 1)
                                *d++ = '?';
                        }
                    }
                    i += l - 1;
                }
            }
            *d = NUL;
            if (lenp != NULL)
                *lenp = (int)(d - retval);
            break;

# ifdef MACOS_CONVERT
        case CONV_MAC_LATIN1:
            retval = mac_string_convert(ptr, len, lenp, vcp->vc_fail,
                                        'm', 'l', unconvlenp);
            break;

        case CONV_LATIN1_MAC:
            retval = mac_string_convert(ptr, len, lenp, vcp->vc_fail,
                                        'l', 'm', unconvlenp);
            break;

        case CONV_MAC_UTF8:
            retval = mac_string_convert(ptr, len, lenp, vcp->vc_fail,
                                        'm', 'u', unconvlenp);
            break;

        case CONV_UTF8_MAC:
            retval = mac_string_convert(ptr, len, lenp, vcp->vc_fail,
                                        'u', 'm', unconvlenp);
            break;
# endif

# ifdef USE_ICONV
        case CONV_ICONV:        /* conversion with output_conv.vc_fd */
            retval = iconv_string(vcp, ptr, len, unconvlenp, lenp);
            break;
# endif
# ifdef WIN3264
        case CONV_CODEPAGE:             /* codepage -> codepage */
        {
            int         retlen;
            int         tmp_len;
            short_u     *tmp;

            /* 1. codepage/UTF-8  ->  ucs-2. */
            if (vcp->vc_cpfrom == 0)
                tmp_len = utf8_to_utf16(ptr, len, NULL, NULL);
            else
                tmp_len = MultiByteToWideChar(vcp->vc_cpfrom, 0,
                                                              ptr, len, 0, 0);
            tmp = (short_u *)alloc(sizeof(short_u) * tmp_len);
            if (tmp == NULL)
                break;
            if (vcp->vc_cpfrom == 0)
                utf8_to_utf16(ptr, len, tmp, unconvlenp);
            else
                MultiByteToWideChar(vcp->vc_cpfrom, 0, ptr, len, tmp, tmp_len);

            /* 2. ucs-2  ->  codepage/UTF-8. */
            if (vcp->vc_cpto == 0)
                retlen = utf16_to_utf8(tmp, tmp_len, NULL);
            else
                retlen = WideCharToMultiByte(vcp->vc_cpto, 0,
                                                    tmp, tmp_len, 0, 0, 0, 0);
            retval = alloc(retlen + 1);
            if (retval != NULL)
            {
                if (vcp->vc_cpto == 0)
                    utf16_to_utf8(tmp, tmp_len, retval);
                else
                    WideCharToMultiByte(vcp->vc_cpto, 0,
                                          tmp, tmp_len, retval, retlen, 0, 0);
                retval[retlen] = NUL;
                if (lenp != NULL)
                    *lenp = retlen;
            }
            vim_free(tmp);
            break;
        }
# endif
    }

    return retval;
}
#endif