lisp/smerge-mode.el

   1 ;;; smerge-mode.el --- Minor mode to resolve diff3 conflicts
   2
   3 ;; Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006,
   4 ;;   2007, 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
   5
   6 ;; Author: Stefan Monnier <monnier@iro.umontreal.ca>
   7 ;; Keywords: tools revision-control merge diff3 cvs conflict
   8
   9 ;; This file is part of GNU Emacs.
  10
  11 ;; GNU Emacs is free software: you can redistribute it and/or modify
  12 ;; it under the terms of the GNU General Public License as published by
  13 ;; the Free Software Foundation, either version 3 of the License, or
  14 ;; (at your option) any later version.
  15
  16 ;; GNU Emacs is distributed in the hope that it will be useful,
  17 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19 ;; GNU General Public License for more details.
  20
  21 ;; You should have received a copy of the GNU General Public License
  22 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  23
  24 ;;; Commentary:
  25
  26 ;; Provides a lightweight alternative to emerge/ediff.
  27 ;; To use it, simply add to your .emacs the following lines:
  28 ;;
  29 ;;   (autoload 'smerge-mode "smerge-mode" nil t)
  30 ;;
  31 ;; you can even have it turned on automatically with the following
  32 ;; piece of code in your .emacs:
  33 ;;
  34 ;;   (defun sm-try-smerge ()
  35 ;;     (save-excursion
  36 ;;       (goto-char (point-min))
  37 ;;       (when (re-search-forward "^<<<<<<< " nil t)
  38 ;;         (smerge-mode 1))))
  39 ;;   (add-hook 'find-file-hook 'sm-try-smerge t)
  40
  41 ;;; Todo:
  42
  43 ;; - if requested, ask the user whether he wants to call ediff right away
  44
  45 ;;; Code:
  46
  47 (eval-when-compile (require 'cl))
  48 (require 'diff-mode)                    ;For diff-auto-refine-mode.
  49
  50
  51 ;;; The real definition comes later.
  52 (defvar smerge-mode)
  53
  54 (defgroup smerge ()
  55   "Minor mode to highlight and resolve diff3 conflicts."
  56   :group 'tools
  57   :prefix "smerge-")
  58
  59 (defcustom smerge-diff-buffer-name "*vc-diff*"
  60   "Buffer name to use for displaying diffs."
  61   :group 'smerge
  62   :type '(choice
  63           (const "*vc-diff*")
  64           (const "*cvs-diff*")
  65           (const "*smerge-diff*")
  66           string))
  67
  68 (defcustom smerge-diff-switches
  69   (append '("-d" "-b")
  70           (if (listp diff-switches) diff-switches (list diff-switches)))
  71   "A list of strings specifying switches to be passed to diff.
  72 Used in `smerge-diff-base-mine' and related functions."
  73   :group 'smerge
  74   :type '(repeat string))
  75
  76 (defcustom smerge-auto-leave t
  77   "Non-nil means to leave `smerge-mode' when the last conflict is resolved."
  78   :group 'smerge
  79   :type 'boolean)
  80
  81 (defface smerge-mine
  82   '((((min-colors 88) (background light))
  83      (:foreground "blue1"))
  84     (((background light))
  85      (:foreground "blue"))
  86     (((min-colors 88) (background dark))
  87      (:foreground "cyan1"))
  88     (((background dark))
  89      (:foreground "cyan")))
  90   "Face for your code."
  91   :group 'smerge)
  92 (define-obsolete-face-alias 'smerge-mine-face 'smerge-mine "22.1")
  93 (defvar smerge-mine-face 'smerge-mine)
  94
  95 (defface smerge-other
  96   '((((background light))
  97      (:foreground "darkgreen"))
  98     (((background dark))
  99      (:foreground "lightgreen")))
 100   "Face for the other code."
 101   :group 'smerge)
 102 (define-obsolete-face-alias 'smerge-other-face 'smerge-other "22.1")
 103 (defvar smerge-other-face 'smerge-other)
 104
 105 (defface smerge-base
 106   '((((min-colors 88) (background light))
 107      (:foreground "red1"))
 108     (((background light))
 109      (:foreground "red"))
 110     (((background dark))
 111      (:foreground "orange")))
 112   "Face for the base code."
 113   :group 'smerge)
 114 (define-obsolete-face-alias 'smerge-base-face 'smerge-base "22.1")
 115 (defvar smerge-base-face 'smerge-base)
 116
 117 (defface smerge-markers
 118   '((((background light))
 119      (:background "grey85"))
 120     (((background dark))
 121      (:background "grey30")))
 122   "Face for the conflict markers."
 123   :group 'smerge)
 124 (define-obsolete-face-alias 'smerge-markers-face 'smerge-markers "22.1")
 125 (defvar smerge-markers-face 'smerge-markers)
 126
 127 (defface smerge-refined-change
 128   '((t :background "yellow"))
 129   "Face used for char-based changes shown by `smerge-refine'."
 130   :group 'smerge)
 131
 132 (easy-mmode-defmap smerge-basic-map
 133   `(("n" . smerge-next)
 134     ("p" . smerge-prev)
 135     ("r" . smerge-resolve)
 136     ("a" . smerge-keep-all)
 137     ("b" . smerge-keep-base)
 138     ("o" . smerge-keep-other)
 139     ("m" . smerge-keep-mine)
 140     ("E" . smerge-ediff)
 141     ("C" . smerge-combine-with-next)
 142     ("R" . smerge-refine)
 143     ("\C-m" . smerge-keep-current)
 144     ("=" . ,(make-sparse-keymap "Diff"))
 145     ("=<" "base-mine" . smerge-diff-base-mine)
 146     ("=>" "base-other" . smerge-diff-base-other)
 147     ("==" "mine-other" . smerge-diff-mine-other))
 148   "The base keymap for `smerge-mode'.")
 149
 150 (defcustom smerge-command-prefix "\C-c^"
 151   "Prefix for `smerge-mode' commands."
 152   :group 'smerge
 153   :type '(choice (const :tag "ESC"   "\e")
 154                  (const :tag "C-c ^" "\C-c^" )
 155                  (const :tag "none"  "")
 156                  string))
 157
 158 (easy-mmode-defmap smerge-mode-map
 159   `((,smerge-command-prefix . ,smerge-basic-map))
 160   "Keymap for `smerge-mode'.")
 161
 162 (defvar smerge-check-cache nil)
 163 (make-variable-buffer-local 'smerge-check-cache)
 164 (defun smerge-check (n)
 165   (condition-case nil
 166       (let ((state (cons (point) (buffer-modified-tick))))
 167         (unless (equal (cdr smerge-check-cache) state)
 168           (smerge-match-conflict)
 169           (setq smerge-check-cache (cons (match-data) state)))
 170         (nth (* 2 n) (car smerge-check-cache)))
 171     (error nil)))
 172
 173 (easy-menu-define smerge-mode-menu smerge-mode-map
 174   "Menu for `smerge-mode'."
 175   '("SMerge"
 176     ["Next" smerge-next :help "Go to next conflict"]
 177     ["Previous" smerge-prev :help "Go to previous conflict"]
 178     "--"
 179     ["Keep All" smerge-keep-all :help "Keep all three versions"
 180      :active (smerge-check 1)]
 181     ["Keep Current" smerge-keep-current :help "Use current (at point) version"
 182      :active (and (smerge-check 1) (> (smerge-get-current) 0))]
 183     "--"
 184     ["Revert to Base" smerge-keep-base :help "Revert to base version"
 185      :active (smerge-check 2)]
 186     ["Keep Other" smerge-keep-other :help "Keep `other' version"
 187      :active (smerge-check 3)]
 188     ["Keep Yours" smerge-keep-mine :help "Keep your version"
 189      :active (smerge-check 1)]
 190     "--"
 191     ["Diff Base/Mine" smerge-diff-base-mine
 192      :help "Diff `base' and `mine' for current conflict"
 193      :active (smerge-check 2)]
 194     ["Diff Base/Other" smerge-diff-base-other
 195      :help "Diff `base' and `other' for current conflict"
 196      :active (smerge-check 2)]
 197     ["Diff Mine/Other" smerge-diff-mine-other
 198      :help "Diff `mine' and `other' for current conflict"
 199      :active (smerge-check 1)]
 200     "--"
 201     ["Invoke Ediff" smerge-ediff
 202      :help "Use Ediff to resolve the conflicts"
 203      :active (smerge-check 1)]
 204     ["Auto Resolve" smerge-resolve
 205      :help "Try auto-resolution heuristics"
 206      :active (smerge-check 1)]
 207     ["Combine" smerge-combine-with-next
 208      :help "Combine current conflict with next"
 209      :active (smerge-check 1)]
 210     ))
 211
 212 (easy-menu-define smerge-context-menu nil
 213   "Context menu for mine area in `smerge-mode'."
 214   '(nil
 215     ["Keep Current" smerge-keep-current :help "Use current (at point) version"]
 216     ["Kill Current" smerge-kill-current :help "Remove current (at point) version"]
 217     ["Keep All" smerge-keep-all :help "Keep all three versions"]
 218     "---"
 219     ["More..." (popup-menu smerge-mode-menu) :help "Show full SMerge mode menu"]
 220     ))
 221
 222 (defconst smerge-font-lock-keywords
 223   '((smerge-find-conflict
 224      (1 smerge-mine-face prepend t)
 225      (2 smerge-base-face prepend t)
 226      (3 smerge-other-face prepend t)
 227      ;; FIXME: `keep' doesn't work right with syntactic fontification.
 228      (0 smerge-markers-face keep)
 229      (4 nil t t)
 230      (5 nil t t)))
 231   "Font lock patterns for `smerge-mode'.")
 232
 233 (defconst smerge-begin-re "^<<<<<<< \\(.*\\)\n")
 234 (defconst smerge-end-re "^>>>>>>> .*\n")
 235 (defconst smerge-base-re "^||||||| .*\n")
 236 (defconst smerge-other-re "^=======\n")
 237
 238 (defvar smerge-conflict-style nil
 239   "Keep track of which style of conflict is in use.
 240 Can be nil if the style is undecided, or else:
 241 - `diff3-E'
 242 - `diff3-A'")
 243
 244 ;; Compiler pacifiers
 245 (defvar font-lock-mode)
 246 (defvar font-lock-keywords)
 247
 248 ;;;;
 249 ;;;; Actual code
 250 ;;;;
 251
 252 ;; Define smerge-next and smerge-prev
 253 (easy-mmode-define-navigation smerge smerge-begin-re "conflict" nil nil
 254   (if diff-auto-refine-mode
 255       (condition-case nil (smerge-refine) (error nil))))
 256
 257 (defconst smerge-match-names ["conflict" "mine" "base" "other"])
 258
 259 (defun smerge-ensure-match (n)
 260   (unless (match-end n)
 261     (error "No `%s'" (aref smerge-match-names n))))
 262
 263 (defun smerge-auto-leave ()
 264   (when (and smerge-auto-leave
 265              (save-excursion (goto-char (point-min))
 266                              (not (re-search-forward smerge-begin-re nil t))))
 267     (when (and (listp buffer-undo-list) smerge-mode)
 268       (push (list 'apply 'smerge-mode 1) buffer-undo-list))
 269     (smerge-mode -1)))
 270
 271
 272 (defun smerge-keep-all ()
 273   "Concatenate all versions."
 274   (interactive)
 275   (smerge-match-conflict)
 276   (let ((mb2 (or (match-beginning 2) (point-max)))
 277         (me2 (or (match-end 2) (point-min))))
 278     (delete-region (match-end 3) (match-end 0))
 279     (delete-region (max me2 (match-end 1)) (match-beginning 3))
 280     (if (and (match-end 2) (/= (match-end 1) (match-end 3)))
 281         (delete-region (match-end 1) (match-beginning 2)))
 282     (delete-region (match-beginning 0) (min (match-beginning 1) mb2))
 283     (smerge-auto-leave)))
 284
 285 (defun smerge-keep-n (n)
 286   (smerge-remove-props (match-beginning 0) (match-end 0))
 287   ;; We used to use replace-match, but that did not preserve markers so well.
 288   (delete-region (match-end n) (match-end 0))
 289   (delete-region (match-beginning 0) (match-beginning n)))
 290
 291 (defun smerge-combine-with-next ()
 292   "Combine the current conflict with the next one."
 293   ;; `smerge-auto-combine' relies on the finish position (at the beginning
 294   ;; of the closing marker).
 295   (interactive)
 296   (smerge-match-conflict)
 297   (let ((ends nil))
 298     (dolist (i '(3 2 1 0))
 299       (push (if (match-end i) (copy-marker (match-end i) t)) ends))
 300     (setq ends (apply 'vector ends))
 301     (goto-char (aref ends 0))
 302     (if (not (re-search-forward smerge-begin-re nil t))
 303         (error "No next conflict")
 304       (smerge-match-conflict)
 305       (let ((match-data (mapcar (lambda (m) (if m (copy-marker m)))
 306                                 (match-data))))
 307         ;; First copy the in-between text in each alternative.
 308         (dolist (i '(1 2 3))
 309           (when (aref ends i)
 310             (goto-char (aref ends i))
 311             (insert-buffer-substring (current-buffer)
 312                                      (aref ends 0) (car match-data))))
 313         (delete-region (aref ends 0) (car match-data))
 314         ;; Then move the second conflict's alternatives into the first.
 315         (dolist (i '(1 2 3))
 316           (set-match-data match-data)
 317           (when (and (aref ends i) (match-end i))
 318             (goto-char (aref ends i))
 319             (insert-buffer-substring (current-buffer)
 320                                      (match-beginning i) (match-end i))))
 321         (delete-region (car match-data) (cadr match-data))
 322         ;; Free the markers.
 323         (dolist (m match-data) (if m (move-marker m nil)))
 324         (mapc (lambda (m) (if m (move-marker m nil))) ends)))))
 325
 326 (defvar smerge-auto-combine-max-separation 2
 327   "Max number of lines between conflicts that should be combined.")
 328
 329 (defun smerge-auto-combine ()
 330   "Automatically combine conflicts that are near each other."
 331   (interactive)
 332   (save-excursion
 333     (goto-char (point-min))
 334     (while (smerge-find-conflict)
 335       ;; 2 is 1 (default) + 1 (the begin markers).
 336       (while (save-excursion
 337                (smerge-find-conflict
 338                 (line-beginning-position
 339                  (+ 2 smerge-auto-combine-max-separation))))
 340         (forward-line -1)               ;Go back inside the conflict.
 341         (smerge-combine-with-next)
 342         (forward-line 1)                ;Move past the end of the conflict.
 343         ))))
 344
 345 (defvar smerge-resolve-function
 346   (lambda () (error "Don't know how to resolve"))
 347   "Mode-specific merge function.
 348 The function is called with zero or one argument (non-nil if the resolution
 349 function should only apply safe heuristics) and with the match data set
 350 according to `smerge-match-conflict'.")
 351 (add-to-list 'debug-ignored-errors "Don't know how to resolve")
 352
 353 (defvar smerge-text-properties
 354   `(help-echo "merge conflict: mouse-3 shows a menu"
 355     ;; mouse-face highlight
 356     keymap (keymap (down-mouse-3 . smerge-popup-context-menu))))
 357
 358 (defun smerge-remove-props (beg end)
 359   (remove-overlays beg end 'smerge 'refine)
 360   (remove-overlays beg end 'smerge 'conflict)
 361   ;; Now that we use overlays rather than text-properties, this function
 362   ;; does not cause refontification any more.  It can be seen very clearly
 363   ;; in buffers where jit-lock-contextually is not t, in which case deleting
 364   ;; the "<<<<<<< foobar" leading line leaves the rest of the conflict
 365   ;; highlighted as if it were still a valid conflict.  Note that in many
 366   ;; important cases (such as the previous example) we're actually called
 367   ;; during font-locking so inhibit-modification-hooks is non-nil, so we
 368   ;; can't just modify the buffer and expect font-lock to be triggered as in:
 369   ;; (put-text-property beg end 'smerge-force-highlighting nil)
 370   (with-silent-modifications
 371     (remove-text-properties beg end '(fontified nil))))
 372
 373 (defun smerge-popup-context-menu (event)
 374   "Pop up the Smerge mode context menu under mouse."
 375   (interactive "e")
 376   (if (and smerge-mode
 377            (save-excursion (posn-set-point (event-end event)) (smerge-check 1)))
 378       (progn
 379         (posn-set-point (event-end event))
 380         (smerge-match-conflict)
 381         (let ((i (smerge-get-current))
 382               o)
 383           (if (<= i 0)
 384               ;; Out of range
 385               (popup-menu smerge-mode-menu)
 386             ;; Install overlay.
 387             (setq o (make-overlay (match-beginning i) (match-end i)))
 388             (unwind-protect
 389                 (progn
 390                   (overlay-put o 'face 'highlight)
 391                   (sit-for 0)           ;Display the new highlighting.
 392                   (popup-menu smerge-context-menu))
 393               ;; Delete overlay.
 394               (delete-overlay o)))))
 395     ;; There's no conflict at point, the text-props are just obsolete.
 396     (save-excursion
 397       (let ((beg (re-search-backward smerge-end-re nil t))
 398             (end (re-search-forward smerge-begin-re nil t)))
 399         (smerge-remove-props (or beg (point-min)) (or end (point-max)))
 400         (push event unread-command-events)))))
 401
 402 (defun smerge-apply-resolution-patch (buf m0b m0e m3b m3e &optional m2b)
 403   "Replace the conflict with a bunch of subconflicts.
 404 BUF contains a plain diff between match-1 and match-3."
 405   (let ((line 1)
 406         (textbuf (current-buffer))
 407         (name1 (progn (goto-char m0b)
 408                       (buffer-substring (+ (point) 8) (line-end-position))))
 409         (name2 (when m2b (goto-char m2b) (forward-line -1)
 410                      (buffer-substring (+ (point) 8) (line-end-position))))
 411         (name3 (progn (goto-char m0e) (forward-line -1)
 412                       (buffer-substring (+ (point) 8) (line-end-position)))))
 413     (smerge-remove-props m0b m0e)
 414     (delete-region m3e m0e)
 415     (delete-region m0b m3b)
 416     (setq m3b m0b)
 417     (setq m3e (- m3e (- m3b m0b)))
 418     (goto-char m3b)
 419     (with-current-buffer buf
 420       (goto-char (point-min))
 421       (while (not (eobp))
 422         (if (not (looking-at "\\([0-9]+\\)\\(?:,\\([0-9]+\\)\\)?\\([acd]\\)\\([0-9]+\\)\\(?:,\\([0-9]+\\)\\)?$"))
 423             (error "Unexpected patch hunk header: %s"
 424                    (buffer-substring (point) (line-end-position)))
 425           (let* ((op (char-after (match-beginning 3)))
 426                  (startline (+ (string-to-number (match-string 1))
 427                                ;; No clue why this is the way it is, but line
 428                                ;; numbers seem to be off-by-one for `a' ops.
 429                                (if (eq op ?a) 1 0)))
 430                  (endline (if (eq op ?a) startline
 431                             (1+ (if (match-end 2)
 432                                     (string-to-number (match-string 2))
 433                                   startline))))
 434                  (lines (- endline startline))
 435                  (otherlines (cond
 436                               ((eq op ?d) nil)
 437                               ((null (match-end 5)) 1)
 438                               (t (- (string-to-number (match-string 5))
 439                                     (string-to-number (match-string 4)) -1))))
 440                  othertext)
 441             (forward-line 1)                             ;Skip header.
 442             (forward-line lines)                         ;Skip deleted text.
 443             (if (eq op ?c) (forward-line 1))             ;Skip separator.
 444             (setq othertext
 445                   (if (null otherlines) ""
 446                     (let ((pos (point)))
 447                       (dotimes (i otherlines) (delete-char 2) (forward-line 1))
 448                       (buffer-substring pos (point)))))
 449             (with-current-buffer textbuf
 450               (forward-line (- startline line))
 451               (insert "<<<<<<< " name1 "\n" othertext
 452                       (if name2 (concat "||||||| " name2 "\n") "")
 453                       "=======\n")
 454               (forward-line lines)
 455               (insert ">>>>>>> " name3 "\n")
 456               (setq line endline))))))))
 457
 458 (defun smerge-resolve (&optional safe)
 459   "Resolve the conflict at point intelligently.
 460 This relies on mode-specific knowledge and thus only works in
 461 some major modes.  Uses `smerge-resolve-function' to do the actual work."
 462   (interactive)
 463   (smerge-match-conflict)
 464   (smerge-remove-props (match-beginning 0) (match-end 0))
 465   (let ((md (match-data))
 466         (m0b (match-beginning 0))
 467         (m1b (match-beginning 1))
 468         (m2b (match-beginning 2))
 469         (m3b (match-beginning 3))
 470         (m0e (match-end 0))
 471         (m1e (match-end 1))
 472         (m2e (match-end 2))
 473         (m3e (match-end 3))
 474         (buf (generate-new-buffer " *smerge*"))
 475         m b o)
 476     (unwind-protect
 477         (progn
 478           (cond
 479            ;; Trivial diff3 -A non-conflicts.
 480            ((and (eq (match-end 1) (match-end 3))
 481                  (eq (match-beginning 1) (match-beginning 3)))
 482             (smerge-keep-n 3))
 483            ;; Mode-specific conflict resolution.
 484            ((condition-case nil
 485                 (atomic-change-group
 486                   (if safe
 487                       (funcall smerge-resolve-function safe)
 488                     (funcall smerge-resolve-function))
 489                   t)
 490               (error nil))
 491             ;; Nothing to do: the resolution function has done it already.
 492             nil)
 493            ;; Non-conflict.
 494            ((and (eq m1e m3e) (eq m1b m3b))
 495             (set-match-data md) (smerge-keep-n 3))
 496            ;; Refine a 2-way conflict using "diff -b".
 497            ;; In case of a 3-way conflict with an empty base
 498            ;; (i.e. 2 conflicting additions), we do the same, presuming
 499            ;; that the 2 additions should be somehow merged rather
 500            ;; than concatenated.
 501            ((let ((lines (count-lines m3b m3e)))
 502               (setq m (make-temp-file "smm"))
 503               (write-region m1b m1e m nil 'silent)
 504               (setq o (make-temp-file "smo"))
 505               (write-region m3b m3e o nil 'silent)
 506               (not (or (eq m1b m1e) (eq m3b m3e)
 507                        (and (not (zerop (call-process diff-command
 508                                                       nil buf nil "-b" o m)))
 509                             ;; TODO: We don't know how to do the refinement
 510                             ;; if there's a non-empty ancestor and m1 and m3
 511                             ;; aren't just plain equal.
 512                             m2b (not (eq m2b m2e)))
 513                        (with-current-buffer buf
 514                          (goto-char (point-min))
 515                          ;; Make sure there's some refinement.
 516                          (looking-at
 517                           (concat "1," (number-to-string lines) "c"))))))
 518             (smerge-apply-resolution-patch buf m0b m0e m3b m3e m2b))
 519            ;; "Mere whitespace changes" conflicts.
 520            ((when m2e
 521               (setq b (make-temp-file "smb"))
 522               (write-region m2b m2e b nil 'silent)
 523               (with-current-buffer buf (erase-buffer))
 524               ;; Only minor whitespace changes made locally.
 525               ;; BEWARE: pass "-c" 'cause the output is reused in the next test.
 526               (zerop (call-process diff-command nil buf nil "-bc" b m)))
 527             (set-match-data md)
 528             (smerge-keep-n 3))
 529            ;; Try "diff -b BASE MINE | patch OTHER".
 530            ((when (and (not safe) m2e b
 531                        ;; If the BASE is empty, this would just concatenate
 532                        ;; the two, which is rarely right.
 533                        (not (eq m2b m2e)))
 534               ;; BEWARE: we're using here the patch of the previous test.
 535               (with-current-buffer buf
 536                 (zerop (call-process-region
 537                         (point-min) (point-max) "patch" t nil nil
 538                         "-r" "/dev/null" "--no-backup-if-mismatch"
 539                         "-fl" o))))
 540             (save-restriction
 541               (narrow-to-region m0b m0e)
 542               (smerge-remove-props m0b m0e)
 543               (insert-file-contents o nil nil nil t)))
 544            ;; Try "diff -b BASE OTHER | patch MINE".
 545            ((when (and (not safe) m2e b
 546                        ;; If the BASE is empty, this would just concatenate
 547                        ;; the two, which is rarely right.
 548                        (not (eq m2b m2e)))
 549               (write-region m3b m3e o nil 'silent)
 550               (call-process diff-command nil buf nil "-bc" b o)
 551               (with-current-buffer buf
 552                 (zerop (call-process-region
 553                         (point-min) (point-max) "patch" t nil nil
 554                         "-r" "/dev/null" "--no-backup-if-mismatch"
 555                         "-fl" m))))
 556             (save-restriction
 557               (narrow-to-region m0b m0e)
 558               (smerge-remove-props m0b m0e)
 559               (insert-file-contents m nil nil nil t)))
 560            (t
 561             (error "Don't know how to resolve"))))
 562       (if (buffer-name buf) (kill-buffer buf))
 563       (if m (delete-file m))
 564       (if b (delete-file b))
 565       (if o (delete-file o))))
 566   (smerge-auto-leave))
 567
 568 (defun smerge-resolve-all ()
 569   "Perform automatic resolution on all conflicts."
 570   (interactive)
 571   (save-excursion
 572     (goto-char (point-min))
 573     (while (re-search-forward smerge-begin-re nil t)
 574       (condition-case nil
 575           (progn
 576             (smerge-match-conflict)
 577             (smerge-resolve 'safe))
 578         (error nil)))))
 579
 580 (defun smerge-batch-resolve ()
 581   ;; command-line-args-left is what is left of the command line.
 582   (if (not noninteractive)
 583       (error "`smerge-batch-resolve' is to be used only with -batch"))
 584   (while command-line-args-left
 585     (let ((file (pop command-line-args-left)))
 586       (if (string-match "\\.rej\\'" file)
 587           ;; .rej files should never contain diff3 markers, on the other hand,
 588           ;; in Arch, .rej files are sometimes used to indicate that the
 589           ;; main file has diff3 markers.  So you can pass **/*.rej and
 590           ;; it will DTRT.
 591           (setq file (substring file 0 (match-beginning 0))))
 592       (message "Resolving conflicts in %s..." file)
 593       (when (file-readable-p file)
 594         (with-current-buffer (find-file-noselect file)
 595           (smerge-resolve-all)
 596           (save-buffer)
 597           (kill-buffer (current-buffer)))))))
 598
 599 (defun smerge-keep-base ()
 600   "Revert to the base version."
 601   (interactive)
 602   (smerge-match-conflict)
 603   (smerge-ensure-match 2)
 604   (smerge-keep-n 2)
 605   (smerge-auto-leave))
 606
 607 (defun smerge-keep-other ()
 608   "Use \"other\" version."
 609   (interactive)
 610   (smerge-match-conflict)
 611   ;;(smerge-ensure-match 3)
 612   (smerge-keep-n 3)
 613   (smerge-auto-leave))
 614
 615 (defun smerge-keep-mine ()
 616   "Keep your version."
 617   (interactive)
 618   (smerge-match-conflict)
 619   ;;(smerge-ensure-match 1)
 620   (smerge-keep-n 1)
 621   (smerge-auto-leave))
 622
 623 (defun smerge-get-current ()
 624   (let ((i 3))
 625     (while (or (not (match-end i))
 626                (< (point) (match-beginning i))
 627                (>= (point) (match-end i)))
 628       (decf i))
 629     i))
 630
 631 (defun smerge-keep-current ()
 632   "Use the current (under the cursor) version."
 633   (interactive)
 634   (smerge-match-conflict)
 635   (let ((i (smerge-get-current)))
 636     (if (<= i 0) (error "Not inside a version")
 637       (smerge-keep-n i)
 638       (smerge-auto-leave))))
 639
 640 (defun smerge-kill-current ()
 641   "Remove the current (under the cursor) version."
 642   (interactive)
 643   (smerge-match-conflict)
 644   (let ((i (smerge-get-current)))
 645     (if (<= i 0) (error "Not inside a version")
 646       (let ((left nil))
 647         (dolist (n '(3 2 1))
 648           (if (and (match-end n) (/= (match-end n) (match-end i)))
 649               (push n left)))
 650         (if (and (cdr left)
 651                  (/= (match-end (car left)) (match-end (cadr left))))
 652             (ding)                      ;We don't know how to do that.
 653           (smerge-keep-n (car left))
 654           (smerge-auto-leave))))))
 655
 656 (defun smerge-diff-base-mine ()
 657   "Diff 'base' and 'mine' version in current conflict region."
 658   (interactive)
 659   (smerge-diff 2 1))
 660
 661 (defun smerge-diff-base-other ()
 662   "Diff 'base' and 'other' version in current conflict region."
 663   (interactive)
 664   (smerge-diff 2 3))
 665
 666 (defun smerge-diff-mine-other ()
 667   "Diff 'mine' and 'other' version in current conflict region."
 668   (interactive)
 669   (smerge-diff 1 3))
 670
 671 (defun smerge-match-conflict ()
 672   "Get info about the conflict.  Puts the info in the `match-data'.
 673 The submatches contain:
 674  0:  the whole conflict.
 675  1:  your code.
 676  2:  the base code.
 677  3:  other code.
 678 An error is raised if not inside a conflict."
 679   (save-excursion
 680     (condition-case nil
 681         (let* ((orig-point (point))
 682
 683                (_ (forward-line 1))
 684                (_ (re-search-backward smerge-begin-re))
 685
 686                (start (match-beginning 0))
 687                (mine-start (match-end 0))
 688                (filename (or (match-string 1) ""))
 689
 690                (_ (re-search-forward smerge-end-re))
 691                (_ (assert (< orig-point (match-end 0))))
 692
 693                (other-end (match-beginning 0))
 694                (end (match-end 0))
 695
 696                (_ (re-search-backward smerge-other-re start))
 697
 698                (mine-end (match-beginning 0))
 699                (other-start (match-end 0))
 700
 701                base-start base-end)
 702
 703           ;; handle the various conflict styles
 704           (cond
 705            ((save-excursion
 706               (goto-char mine-start)
 707               (re-search-forward smerge-begin-re end t))
 708             ;; There's a nested conflict and we're after the beginning
 709             ;; of the outer one but before the beginning of the inner one.
 710             ;; Of course, maybe this is not a nested conflict but in that
 711             ;; case it can only be something nastier that we don't know how
 712             ;; to handle, so may as well arbitrarily decide to treat it as
 713             ;; a nested conflict.  --Stef
 714             (error "There is a nested conflict"))
 715
 716            ((re-search-backward smerge-base-re start t)
 717             ;; a 3-parts conflict
 718             (set (make-local-variable 'smerge-conflict-style) 'diff3-A)
 719             (setq base-end mine-end)
 720             (setq mine-end (match-beginning 0))
 721             (setq base-start (match-end 0)))
 722
 723            ((string= filename (file-name-nondirectory
 724                                (or buffer-file-name "")))
 725             ;; a 2-parts conflict
 726             (set (make-local-variable 'smerge-conflict-style) 'diff3-E))
 727
 728            ((and (not base-start)
 729                  (or (eq smerge-conflict-style 'diff3-A)
 730                      (equal filename "ANCESTOR")
 731                      (string-match "\\`[.0-9]+\\'" filename)))
 732             ;; a same-diff conflict
 733             (setq base-start mine-start)
 734             (setq base-end   mine-end)
 735             (setq mine-start other-start)
 736             (setq mine-end   other-end)))
 737
 738           (store-match-data (list start end
 739                                   mine-start mine-end
 740                                   base-start base-end
 741                                   other-start other-end
 742                                   (when base-start (1- base-start)) base-start
 743                                   (1- other-start) other-start))
 744           t)
 745       (search-failed (error "Point not in conflict region")))))
 746
 747 (add-to-list 'debug-ignored-errors "Point not in conflict region")
 748
 749 (defun smerge-conflict-overlay (pos)
 750   "Return the conflict overlay at POS if any."
 751   (let ((ols (overlays-at pos))
 752         conflict)
 753     (dolist (ol ols)
 754       (if (and (eq (overlay-get ol 'smerge) 'conflict)
 755                (> (overlay-end ol) pos))
 756           (setq conflict ol)))
 757     conflict))
 758
 759 (defun smerge-find-conflict (&optional limit)
 760   "Find and match a conflict region.  Intended as a font-lock MATCHER.
 761 The submatches are the same as in `smerge-match-conflict'.
 762 Returns non-nil if a match is found between point and LIMIT.
 763 Point is moved to the end of the conflict."
 764   (let ((found nil)
 765         (pos (point))
 766         conflict)
 767     ;; First check to see if point is already inside a conflict, using
 768     ;; the conflict overlays.
 769     (while (and (not found) (setq conflict (smerge-conflict-overlay pos)))
 770       ;; Check the overlay's validity and kill it if it's out of date.
 771       (condition-case nil
 772           (progn
 773             (goto-char (overlay-start conflict))
 774             (smerge-match-conflict)
 775             (goto-char (match-end 0))
 776             (if (<= (point) pos)
 777                 (error "Matching backward!")
 778               (setq found t)))
 779         (error (smerge-remove-props
 780                 (overlay-start conflict) (overlay-end conflict))
 781                (goto-char pos))))
 782     ;; If we're not already inside a conflict, look for the next conflict
 783     ;; and add/update its overlay.
 784     (while (and (not found) (re-search-forward smerge-begin-re limit t))
 785       (condition-case nil
 786           (progn
 787             (smerge-match-conflict)
 788             (goto-char (match-end 0))
 789             (let ((conflict (smerge-conflict-overlay (1- (point)))))
 790               (if conflict
 791                   ;; Update its location, just in case it got messed up.
 792                   (move-overlay conflict (match-beginning 0) (match-end 0))
 793                 (setq conflict (make-overlay (match-beginning 0) (match-end 0)
 794                                              nil 'front-advance nil))
 795                 (overlay-put conflict 'evaporate t)
 796                 (overlay-put conflict 'smerge 'conflict)
 797                 (let ((props smerge-text-properties))
 798                   (while props
 799                     (overlay-put conflict (pop props) (pop props))))))
 800             (setq found t))
 801         (error nil)))
 802     found))
 803
 804 ;;; Refined change highlighting
 805
 806 (defvar smerge-refine-forward-function 'smerge-refine-forward
 807   "Function used to determine an \"atomic\" element.
 808 You can set it to `forward-char' to get char-level granularity.
 809 Its behavior has mainly two restrictions:
 810 - if this function encounters a newline, it's important that it stops right
 811   after the newline.
 812   This only matters if `smerge-refine-ignore-whitespace' is nil.
 813 - it needs to be unaffected by changes performed by the `preproc' argument
 814   to `smerge-refine-subst'.
 815   This only matters if `smerge-refine-weight-hack' is nil.")
 816
 817 (defvar smerge-refine-ignore-whitespace t
 818   "If non-nil,Indicate that smerge-refine should try to ignore change in whitespace.")
 819
 820 (defvar smerge-refine-weight-hack t
 821   "If non-nil, pass to diff as many lines as there are chars in the region.
 822 I.e. each atomic element (e.g. word) will be copied as many times (on different
 823 lines) as it has chars.  This has 2 advantages:
 824 - if `diff' tries to minimize the number *lines* (rather than chars)
 825   added/removed, this adjust the weights so that adding/removing long
 826   symbols is considered correspondingly more costly.
 827 - `smerge-refine-forward-function' only needs to be called when chopping up
 828   the regions, and `forward-char' can be used afterwards.
 829 It has the following disadvantages:
 830 - cannot use `diff -w' because the weighting causes added spaces in a line
 831   to be represented as added copies of some line, so `diff -w' can't do the
 832   right thing any more.
 833 - may in degenerate cases take a 1KB input region and turn it into a 1MB
 834   file to pass to diff.")
 835
 836 (defun smerge-refine-forward (n)
 837   (let ((case-fold-search nil)
 838         (re "[[:upper:]]?[[:lower:]]+\\|[[:upper:]]+\\|[[:digit:]]+\\|.\\|\n"))
 839     (when (and smerge-refine-ignore-whitespace
 840                ;; smerge-refine-weight-hack causes additional spaces to
 841                ;; appear as additional lines as well, so even if diff ignore
 842                ;; whitespace changes, it'll report added/removed lines :-(
 843                (not smerge-refine-weight-hack))
 844       (setq re (concat "[ \t]*\\(?:" re "\\)")))
 845     (dotimes (i n)
 846       (unless (looking-at re) (error "Smerge refine internal error"))
 847       (goto-char (match-end 0)))))
 848
 849 (defun smerge-refine-chopup-region (beg end file &optional preproc)
 850   "Chopup the region into small elements, one per line.
 851 Save the result into FILE.
 852 If non-nil, PREPROC is called with no argument in a buffer that contains
 853 a copy of the text, just before chopping it up.  It can be used to replace
 854 chars to try and eliminate some spurious differences."
 855   ;; We used to chop up char-by-char rather than word-by-word like ediff
 856   ;; does.  It had the benefit of simplicity and very fine results, but it
 857   ;; often suffered from problem that diff would find correlations where
 858   ;; there aren't any, so the resulting "change" didn't make much sense.
 859   ;; You can still get this behavior by setting
 860   ;; `smerge-refine-forward-function' to `forward-char'.
 861   (let ((buf (current-buffer)))
 862     (with-temp-buffer
 863       (insert-buffer-substring buf beg end)
 864       (when preproc (goto-char (point-min)) (funcall preproc))
 865       (when smerge-refine-ignore-whitespace
 866         ;; It doesn't make much of a difference for diff-fine-highlight
 867         ;; because we still have the _/+/</>/! prefix anyway.  Can still be
 868         ;; useful in other circumstances.
 869         (subst-char-in-region (point-min) (point-max) ?\n ?\s))
 870       (goto-char (point-min))
 871       (while (not (eobp))
 872         (funcall smerge-refine-forward-function 1)
 873         (let ((s (if (prog2 (forward-char -1) (bolp) (forward-char 1))
 874                      nil
 875                    (buffer-substring (line-beginning-position) (point)))))
 876           ;; We add \n after each char except after \n, so we get
 877           ;; one line per text char, where each line contains
 878           ;; just one char, except for \n chars which are
 879           ;; represented by the empty line.
 880           (unless (eq (char-before) ?\n) (insert ?\n))
 881           ;; HACK ALERT!!
 882           (if smerge-refine-weight-hack
 883               (dotimes (i (1- (length s))) (insert s "\n")))))
 884       (unless (bolp) (error "Smerge refine internal error"))
 885       (let ((coding-system-for-write 'emacs-mule))
 886         (write-region (point-min) (point-max) file nil 'nomessage)))))
 887
 888 (defun smerge-refine-highlight-change (buf beg match-num1 match-num2 props)
 889   (with-current-buffer buf
 890     (goto-char beg)
 891     (let* ((startline (- (string-to-number match-num1) 1))
 892            (beg (progn (funcall (if smerge-refine-weight-hack
 893                                     'forward-char
 894                                   smerge-refine-forward-function)
 895                                 startline)
 896                        (point)))
 897            (end (progn (funcall (if smerge-refine-weight-hack
 898                                     'forward-char
 899                                   smerge-refine-forward-function)
 900                           (if match-num2
 901                               (- (string-to-number match-num2)
 902                                  startline)
 903                             1))
 904                        (point))))
 905       (when smerge-refine-ignore-whitespace
 906         (skip-chars-backward " \t\n" beg) (setq end (point))
 907         (goto-char beg)
 908         (skip-chars-forward " \t\n" end)  (setq beg (point)))
 909       (when (> end beg)
 910         (let ((ol (make-overlay
 911                    beg end nil
 912                    ;; Make them tend to shrink rather than spread when editing.
 913                    'front-advance nil)))
 914           (overlay-put ol 'evaporate t)
 915           (dolist (x props) (overlay-put ol (car x) (cdr x)))
 916           ol)))))
 917
 918 (defun smerge-refine-subst (beg1 end1 beg2 end2 props &optional preproc)
 919   "Show fine differences in the two regions BEG1..END1 and BEG2..END2.
 920 PROPS is an alist of properties to put (via overlays) on the changes.
 921 If non-nil, PREPROC is called with no argument in a buffer that contains
 922 a copy of a region, just before preparing it to for `diff'.  It can be used to
 923 replace chars to try and eliminate some spurious differences."
 924   (let* ((buf (current-buffer))
 925          (pos (point))
 926          (file1 (make-temp-file "diff1"))
 927          (file2 (make-temp-file "diff2")))
 928     ;; Chop up regions into smaller elements and save into files.
 929     (smerge-refine-chopup-region beg1 end1 file1 preproc)
 930     (smerge-refine-chopup-region beg2 end2 file2 preproc)
 931
 932     ;; Call diff on those files.
 933     (unwind-protect
 934         (with-temp-buffer
 935           (let ((coding-system-for-read 'emacs-mule))
 936             (call-process diff-command nil t nil
 937                           (if (and smerge-refine-ignore-whitespace
 938                                    (not smerge-refine-weight-hack))
 939                               ;; Pass -a so diff treats it as a text file even
 940                               ;; if it contains \0 and such.
 941                               ;; Pass -d so as to get the smallest change, but
 942                               ;; also and more importantly because otherwise it
 943                               ;; may happen that diff doesn't behave like
 944                               ;; smerge-refine-weight-hack expects it to.
 945                               ;; See http://thread.gmane.org/gmane.emacs.devel/82685.
 946                               "-awd" "-ad")
 947                           file1 file2))
 948           ;; Process diff's output.
 949           (goto-char (point-min))
 950           (let ((last1 nil)
 951                 (last2 nil))
 952             (while (not (eobp))
 953               (if (not (looking-at "\\([0-9]+\\)\\(?:,\\([0-9]+\\)\\)?\\([acd]\\)\\([0-9]+\\)\\(?:,\\([0-9]+\\)\\)?$"))
 954                   (error "Unexpected patch hunk header: %s"
 955                          (buffer-substring (point) (line-end-position))))
 956               (let ((op (char-after (match-beginning 3)))
 957                     (m1 (match-string 1))
 958                     (m2 (match-string 2))
 959                     (m4 (match-string 4))
 960                     (m5 (match-string 5)))
 961                 (when (memq op '(?d ?c))
 962                   (setq last1
 963                         (smerge-refine-highlight-change buf beg1 m1 m2 props)))
 964                 (when (memq op '(?a ?c))
 965                   (setq last2
 966                         (smerge-refine-highlight-change buf beg2 m4 m5 props))))
 967               (forward-line 1)                            ;Skip hunk header.
 968               (and (re-search-forward "^[0-9]" nil 'move) ;Skip hunk body.
 969                    (goto-char (match-beginning 0))))
 970             ;; (assert (or (null last1) (< (overlay-start last1) end1)))
 971             ;; (assert (or (null last2) (< (overlay-start last2) end2)))
 972             (if smerge-refine-weight-hack
 973                 (progn
 974                   ;; (assert (or (null last1) (<= (overlay-end last1) end1)))
 975                   ;; (assert (or (null last2) (<= (overlay-end last2) end2)))
 976                   )
 977               ;; smerge-refine-forward-function when calling in chopup may
 978               ;; have stopped because it bumped into EOB whereas in
 979               ;; smerge-refine-weight-hack it may go a bit further.
 980               (if (and last1 (> (overlay-end last1) end1))
 981                   (move-overlay last1 (overlay-start last1) end1))
 982               (if (and last2 (> (overlay-end last2) end2))
 983                   (move-overlay last2 (overlay-start last2) end2))
 984               )))
 985       (goto-char pos)
 986       (delete-file file1)
 987       (delete-file file2))))
 988
 989 (defun smerge-refine (&optional part)
 990   "Highlight the words of the conflict that are different.
 991 For 3-way conflicts, highlights only 2 of the 3 parts.
 992 A numeric argument PART can be used to specify which 2 parts;
 993 repeating the command will highlight other 2 parts."
 994   (interactive
 995    (if (integerp current-prefix-arg) (list current-prefix-arg)
 996      (smerge-match-conflict)
 997      (let* ((prop (get-text-property (match-beginning 0) 'smerge-refine-part))
 998             (part (if (and (consp prop)
 999                            (eq (buffer-chars-modified-tick) (car prop)))
1000                       (cdr prop))))
1001        ;; If already highlighted, cycle.
1002        (list (if (integerp part) (1+ (mod part 3)))))))
1003
1004   (if (and (integerp part) (or (< part 1) (> part 3)))
1005       (error "No conflict part nb %s" part))
1006   (smerge-match-conflict)
1007   (remove-overlays (match-beginning 0) (match-end 0) 'smerge 'refine)
1008   ;; Ignore `part' if not applicable, and default it if not provided.
1009   (setq part (cond ((null (match-end 2)) 2)
1010                    ((eq (match-end 1) (match-end 3)) 1)
1011                    ((integerp part) part)
1012                    (t 2)))
1013   (let ((n1 (if (eq part 1) 2 1))
1014         (n2 (if (eq part 3) 2 3)))
1015     (smerge-ensure-match n1)
1016     (smerge-ensure-match n2)
1017     (with-silent-modifications
1018       (put-text-property (match-beginning 0) (1+ (match-beginning 0))
1019                          'smerge-refine-part
1020                          (cons (buffer-chars-modified-tick) part)))
1021     (smerge-refine-subst (match-beginning n1) (match-end n1)
1022                          (match-beginning n2)  (match-end n2)
1023                          '((smerge . refine)
1024                            (face . smerge-refined-change)))))
1025
1026 (defun smerge-diff (n1 n2)
1027   (smerge-match-conflict)
1028   (smerge-ensure-match n1)
1029   (smerge-ensure-match n2)
1030   (let ((name1 (aref smerge-match-names n1))
1031         (name2 (aref smerge-match-names n2))
1032         ;; Read them before the match-data gets clobbered.
1033         (beg1 (match-beginning n1))
1034         (end1 (match-end n1))
1035         (beg2 (match-beginning n2))
1036         (end2 (match-end n2))
1037         (file1 (make-temp-file "smerge1"))
1038         (file2 (make-temp-file "smerge2"))
1039         (dir default-directory)
1040         (file (if buffer-file-name (file-relative-name buffer-file-name)))
1041         ;; We would want to use `emacs-mule-unix' for read&write, but we
1042         ;; bump into problems with the coding-system used by diff to write
1043         ;; the file names and the time stamps in the header.
1044         ;; `buffer-file-coding-system' is not always correct either, but if
1045         ;; the OS/user uses only one coding-system, then it works.
1046         (coding-system-for-read buffer-file-coding-system))
1047     (write-region beg1 end1 file1 nil 'nomessage)
1048     (write-region beg2 end2 file2 nil 'nomessage)
1049     (unwind-protect
1050         (with-current-buffer (get-buffer-create smerge-diff-buffer-name)
1051           (setq default-directory dir)
1052           (let ((inhibit-read-only t))
1053             (erase-buffer)
1054             (let ((status
1055                    (apply 'call-process diff-command nil t nil
1056                           (append smerge-diff-switches
1057                                   (list "-L" (concat name1 "/" file)
1058                                         "-L" (concat name2 "/" file)
1059                                         file1 file2)))))
1060               (if (eq status 0) (insert "No differences found.\n"))))
1061           (goto-char (point-min))
1062           (diff-mode)
1063           (display-buffer (current-buffer) t))
1064       (delete-file file1)
1065       (delete-file file2))))
1066
1067 ;; compiler pacifiers
1068 (defvar smerge-ediff-windows)
1069 (defvar smerge-ediff-buf)
1070 (defvar ediff-buffer-A)
1071 (defvar ediff-buffer-B)
1072 (defvar ediff-buffer-C)
1073 (defvar ediff-ancestor-buffer)
1074 (defvar ediff-quit-hook)
1075 (declare-function ediff-cleanup-mess "ediff-util" nil)
1076
1077 ;;;###autoload
1078 (defun smerge-ediff (&optional name-mine name-other name-base)
1079   "Invoke ediff to resolve the conflicts.
1080 NAME-MINE, NAME-OTHER, and NAME-BASE, if non-nil, are used for the
1081 buffer names."
1082   (interactive)
1083   (let* ((buf (current-buffer))
1084          (mode major-mode)
1085          ;;(ediff-default-variant 'default-B)
1086          (config (current-window-configuration))
1087          (filename (file-name-nondirectory buffer-file-name))
1088          (mine (generate-new-buffer
1089                 (or name-mine (concat "*" filename " MINE*"))))
1090          (other (generate-new-buffer
1091                  (or name-other (concat "*" filename " OTHER*"))))
1092          base)
1093     (with-current-buffer mine
1094       (buffer-disable-undo)
1095       (insert-buffer-substring buf)
1096       (goto-char (point-min))
1097       (while (smerge-find-conflict)
1098         (when (match-beginning 2) (setq base t))
1099         (smerge-keep-n 1))
1100       (buffer-enable-undo)
1101       (set-buffer-modified-p nil)
1102       (funcall mode))
1103
1104     (with-current-buffer other
1105       (buffer-disable-undo)
1106       (insert-buffer-substring buf)
1107       (goto-char (point-min))
1108       (while (smerge-find-conflict)
1109         (smerge-keep-n 3))
1110       (buffer-enable-undo)
1111       (set-buffer-modified-p nil)
1112       (funcall mode))
1113
1114     (when base
1115       (setq base (generate-new-buffer
1116                   (or name-base (concat "*" filename " BASE*"))))
1117       (with-current-buffer base
1118         (buffer-disable-undo)
1119         (insert-buffer-substring buf)
1120         (goto-char (point-min))
1121         (while (smerge-find-conflict)
1122           (if (match-end 2)
1123               (smerge-keep-n 2)
1124             (delete-region (match-beginning 0) (match-end 0))))
1125         (buffer-enable-undo)
1126         (set-buffer-modified-p nil)
1127         (funcall mode)))
1128
1129     ;; the rest of the code is inspired from vc.el
1130     ;; Fire up ediff.
1131     (set-buffer
1132      (if base
1133          (ediff-merge-buffers-with-ancestor mine other base)
1134           ;; nil 'ediff-merge-revisions-with-ancestor buffer-file-name)
1135        (ediff-merge-buffers mine other)))
1136         ;; nil 'ediff-merge-revisions buffer-file-name)))
1137
1138     ;; Ediff is now set up, and we are in the control buffer.
1139     ;; Do a few further adjustments and take precautions for exit.
1140     (set (make-local-variable 'smerge-ediff-windows) config)
1141     (set (make-local-variable 'smerge-ediff-buf) buf)
1142     (set (make-local-variable 'ediff-quit-hook)
1143          (lambda ()
1144            (let ((buffer-A ediff-buffer-A)
1145                  (buffer-B ediff-buffer-B)
1146                  (buffer-C ediff-buffer-C)
1147                  (buffer-Ancestor ediff-ancestor-buffer)
1148                  (buf smerge-ediff-buf)
1149                  (windows smerge-ediff-windows))
1150              (ediff-cleanup-mess)
1151              (with-current-buffer buf
1152                (erase-buffer)
1153                (insert-buffer-substring buffer-C)
1154                (kill-buffer buffer-A)
1155                (kill-buffer buffer-B)
1156                (kill-buffer buffer-C)
1157                (when (bufferp buffer-Ancestor) (kill-buffer buffer-Ancestor))
1158                (set-window-configuration windows)
1159                (message "Conflict resolution finished; you may save the buffer")))))
1160     (message "Please resolve conflicts now; exit ediff when done")))
1161
1162 (defun smerge-makeup-conflict (pt1 pt2 pt3 &optional pt4)
1163   "Insert diff3 markers to make a new conflict.
1164 Uses point and mark for 2 of the relevant positions and previous marks
1165 for the other ones.
1166 By default, makes up a 2-way conflict,
1167 with a \\[universal-argument] prefix, makes up a 3-way conflict."
1168   (interactive
1169    (list (point)
1170          (mark)
1171          (progn (pop-mark) (mark))
1172          (when current-prefix-arg (pop-mark) (mark))))
1173   ;; Start from the end so as to avoid problems with pos-changes.
1174   (destructuring-bind (pt1 pt2 pt3 &optional pt4)
1175       (sort (list* pt1 pt2 pt3 (if pt4 (list pt4))) '>=)
1176     (goto-char pt1) (beginning-of-line)
1177     (insert ">>>>>>> OTHER\n")
1178     (goto-char pt2) (beginning-of-line)
1179     (insert "=======\n")
1180     (goto-char pt3) (beginning-of-line)
1181     (when pt4
1182       (insert "||||||| BASE\n")
1183       (goto-char pt4) (beginning-of-line))
1184     (insert "<<<<<<< MINE\n"))
1185   (if smerge-mode nil (smerge-mode 1))
1186   (smerge-refine))
1187
1188
1189 (defconst smerge-parsep-re
1190   (concat smerge-begin-re "\\|" smerge-end-re "\\|"
1191           smerge-base-re "\\|" smerge-other-re "\\|"))
1192
1193 ;;;###autoload
1194 (define-minor-mode smerge-mode
1195   "Minor mode to simplify editing output from the diff3 program.
1196 \\{smerge-mode-map}"
1197   :group 'smerge :lighter " SMerge"
1198   (when (and (boundp 'font-lock-mode) font-lock-mode)
1199     (save-excursion
1200       (if smerge-mode
1201           (font-lock-add-keywords nil smerge-font-lock-keywords 'append)
1202         (font-lock-remove-keywords nil smerge-font-lock-keywords))
1203       (goto-char (point-min))
1204       (while (smerge-find-conflict)
1205         (save-excursion
1206           (font-lock-fontify-region (match-beginning 0) (match-end 0) nil)))))
1207   (if (string-match (regexp-quote smerge-parsep-re) paragraph-separate)
1208       (unless smerge-mode
1209         (set (make-local-variable 'paragraph-separate)
1210              (replace-match "" t t paragraph-separate)))
1211     (when smerge-mode
1212         (set (make-local-variable 'paragraph-separate)
1213              (concat smerge-parsep-re paragraph-separate))))
1214   (unless smerge-mode
1215     (smerge-remove-props (point-min) (point-max))))
1216
1217 ;;;###autoload
1218 (defun smerge-start-session ()
1219   "Turn on `smerge-mode' and move point to first conflict marker.
1220 If no conflict maker is found, turn off `smerge-mode'."
1221   (interactive)
1222   (smerge-mode 1)
1223   (condition-case nil
1224       (unless (looking-at smerge-begin-re)
1225         (smerge-next))
1226     (error (smerge-auto-leave))))
1227
1228 (provide 'smerge-mode)
1229
1230 ;; arch-tag: 605c8d1e-e43d-4943-a6f3-1bcc4333e690
1231 ;;; smerge-mode.el ends here