lisp/diff-mode.el

   1 ;;; diff-mode.el --- A mode for viewing/editing context diffs
   2
   3 ;; Copyright (C) 1998, 1999, 2000  Free Software Foundation, Inc.
   4
   5 ;; Author: Stefan Monnier <monnier@cs.yale.edu>
   6 ;; Keywords: patch diff
   7
   8 ;; This file is part of GNU Emacs.
   9
  10 ;; GNU Emacs is free software; you can redistribute it and/or modify
  11 ;; it under the terms of the GNU General Public License as published by
  12 ;; the Free Software Foundation; either version 2, or (at your option)
  13 ;; any later version.
  14
  15 ;; GNU Emacs is distributed in the hope that it will be useful,
  16 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 ;; GNU General Public License for more details.
  19
  20 ;; You should have received a copy of the GNU General Public License
  21 ;; along with GNU Emacs; see the file COPYING.  If not, write to the
  22 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  23 ;; Boston, MA 02111-1307, USA.
  24
  25 ;;; Commentary:
  26
  27 ;; Provides support for font-lock, outline, navigation
  28 ;; commands, editing and various conversions as well as jumping
  29 ;; to the corresponding source file.
  30
  31 ;; inspired by Pavel Machek's patch-mode.el (<pavel@atrey.karlin.mff.cuni.cz>)
  32 ;; some efforts were spent to have it somewhat compatible with XEmacs'
  33 ;; diff-mode as well as with compilation-minor-mode
  34
  35 ;; to use it, simply add to your .emacs the following lines:
  36 ;;
  37 ;; (autoload 'diff-mode "diff-mode" "Diff major mode" t)
  38 ;; (add-to-list 'auto-mode-alist '("\\.\\(diffs?\\|patch\\|rej\\)\\'" . diff-mode))
  39
  40 ;; Bugs:
  41
  42 ;; - Reverse doesn't work with normal diffs.
  43
  44 ;; Todo:
  45
  46 ;; - Improve narrowed-view support.
  47 ;; - re-enable (conditionally) the `compile' support after improving it to use
  48 ;;   the same code as diff-goto-source.
  49 ;; - Support for # comments in context->unified.
  50 ;; - Do a fuzzy search in diff-goto-source.
  51 ;; - Allow diff.el to use diff-mode.
  52 ;;   This mostly means ability to jump from half-hunk to half-hunk
  53 ;;   in context (and normal) diffs and to jump to the corresponding
  54 ;;   (i.e. new or old) file.
  55 ;; - Handle `diff -b' output in context->unified.
  56
  57 ;; Low priority:
  58 ;; - Spice up the minor-mode with font-lock support.
  59 ;; - Recognize pcl-cvs' special string for `cvs-execute-single'.
  60
  61 ;;; Code:
  62
  63 (eval-when-compile (require 'cl))
  64
  65
  66 (defgroup diff-mode ()
  67   "Major mode for viewing/editing diffs"
  68   :version "21.1"
  69   :group 'tools
  70   :group 'diff)
  71
  72 (defcustom diff-jump-to-old-file-flag nil
  73   "*Non-nil means `diff-goto-source' jumps to the old file.
  74 Else, it jumps to the new file."
  75   :group 'diff-mode
  76   :type '(boolean))
  77
  78 (defcustom diff-update-on-the-fly-flag t
  79   "*Non-nil means hunk headers are kept up-to-date on-the-fly.
  80 When editing a diff file, the line numbers in the hunk headers
  81 need to be kept consistent with the actual diff.  This can
  82 either be done on the fly (but this sometimes interacts poorly with the
  83 undo mechanism) or whenever the file is written (can be slow
  84 when editing big diffs)."
  85   :group 'diff-mode
  86   :type '(boolean))
  87
  88 (defcustom diff-advance-after-apply-hunk t
  89   "*Non-nil means `diff-apply-hunk' will move to the next hunk after applying."
  90   :group 'diff-mode
  91   :type 'boolean)
  92
  93
  94 (defvar diff-mode-hook nil
  95   "Run after setting up the `diff-mode' major mode.")
  96
  97 (defvar diff-outline-regexp
  98   "\\([*+][*+][*+] [^0-9]\\|@@ ...\\|\\*\\*\\* [0-9].\\|--- [0-9]..\\)")
  99
 100 ;;;;
 101 ;;;; keymap, menu, ...
 102 ;;;;
 103
 104 (easy-mmode-defmap diff-mode-shared-map
 105   '(;; From Pavel Machek's patch-mode.
 106     ("n" . diff-hunk-next)
 107     ("N" . diff-file-next)
 108     ("p" . diff-hunk-prev)
 109     ("P" . diff-file-prev)
 110     ("k" . diff-hunk-kill)
 111     ("K" . diff-file-kill)
 112     ;; From compilation-minor-mode.
 113     ("}" . diff-file-next)
 114     ("{" . diff-file-prev)
 115     ("\C-m" . diff-goto-source)
 116     ([mouse-2] . diff-mouse-goto-source)
 117     ;; From XEmacs' diff-mode.
 118     ("W" . widen)
 119     ;;("." . diff-goto-source)          ;display-buffer
 120     ;;("f" . diff-goto-source)          ;find-file
 121     ("o" . diff-goto-source)            ;other-window
 122     ;;("w" . diff-goto-source)          ;other-frame
 123     ;;("N" . diff-narrow)
 124     ;;("h" . diff-show-header)
 125     ;;("j" . diff-show-difference)      ;jump to Nth diff
 126     ;;("q" . diff-quit)
 127     (" " . scroll-up)
 128     ("\177" . scroll-down)
 129     ;; Our very own bindings.
 130     ("A" . diff-ediff-patch)
 131     ("r" . diff-restrict-view)
 132     ("R" . diff-reverse-direction)
 133     ("U" . diff-context->unified)
 134     ("C" . diff-unified->context))
 135   "Basic keymap for `diff-mode', bound to various prefix keys.")
 136
 137 (easy-mmode-defmap diff-mode-map
 138   `(("\e" . ,diff-mode-shared-map)
 139     ;; From compilation-minor-mode.
 140     ("\C-c\C-c" . diff-goto-source)
 141     ;; Misc operations.
 142     ("\C-c\C-s" . diff-split-hunk)
 143     ("\C-c\C-a" . diff-apply-hunk)
 144     ("\C-c\C-t" . diff-test-hunk))
 145   "Keymap for `diff-mode'.  See also `diff-mode-shared-map'.")
 146
 147 (easy-menu-define diff-mode-menu diff-mode-map
 148   "Menu for `diff-mode'."
 149   '("Diff"
 150     ["Jump to Source"           diff-goto-source        t]
 151     ["Apply hunk"               diff-apply-hunk         t]
 152     ["Apply diff with Ediff"    diff-ediff-patch        t]
 153     ["-----" nil nil]
 154     ["Reverse direction"        diff-reverse-direction  t]
 155     ["Context -> Unified"       diff-context->unified   t]
 156     ["Unified -> Context"       diff-unified->context   t]
 157     ;;["Fixup Headers"          diff-fixup-modifs       (not buffer-read-only)]
 158     ))
 159
 160 (defcustom diff-minor-mode-prefix "\C-c="
 161   "Prefix key for `diff-minor-mode' commands."
 162   :group 'diff-mode
 163   :type '(choice (string "\e") (string "C-c=") string))
 164
 165 (easy-mmode-defmap diff-minor-mode-map
 166   `((,diff-minor-mode-prefix . ,diff-mode-shared-map))
 167   "Keymap for `diff-minor-mode'.  See also `diff-mode-shared-map'.")
 168
 169
 170 ;;;;
 171 ;;;; font-lock support
 172 ;;;;
 173
 174 (defface diff-header-face
 175   '((((type tty pc) (class color) (background light))
 176      (:foreground "blue1" :bold t))
 177     (((type tty pc) (class color) (background dark))
 178      (:foreground "green" :bold t))
 179     (((class color) (background light))
 180      (:background "grey85"))
 181     (((class color) (background dark))
 182      (:background "grey45"))
 183     (t (:bold t)))
 184   "`diff-mode' face inherited by hunk and index header faces."
 185   :group 'diff-mode)
 186 (defvar diff-header-face 'diff-header-face)
 187
 188 (defface diff-file-header-face
 189   '((((type tty pc) (class color) (background light))
 190      (:foreground "yellow" :bold t))
 191     (((type tty pc) (class color) (background dark))
 192      (:foreground "cyan" :bold t))
 193     (((class color) (background light))
 194      (:background "grey70" :bold t))
 195     (((class color) (background dark))
 196      (:background "grey60" :bold t))
 197     (t (:bold t)))                      ; :height 1.3
 198   "`diff-mode' face used to highlight file header lines."
 199   :group 'diff-mode)
 200 (defvar diff-file-header-face 'diff-file-header-face)
 201
 202 (defface diff-index-face
 203   '((t (:inherit diff-file-header-face)))
 204   "`diff-mode' face used to highlight index header lines."
 205   :group 'diff-mode)
 206 (defvar diff-index-face 'diff-index-face)
 207
 208 (defface diff-hunk-header-face
 209   '((t (:inherit diff-header-face)))
 210   "`diff-mode' face used to highlight hunk header lines."
 211   :group 'diff-mode)
 212 (defvar diff-hunk-header-face 'diff-hunk-header-face)
 213
 214 (defface diff-removed-face
 215   '((t (:inherit diff-changed-face)))
 216   "`diff-mode' face used to highlight removed lines."
 217   :group 'diff-mode)
 218 (defvar diff-removed-face 'diff-removed-face)
 219
 220 (defface diff-added-face
 221   '((t (:inherit diff-changed-face)))
 222   "`diff-mode' face used to highlight added lines."
 223   :group 'diff-mode)
 224 (defvar diff-added-face 'diff-added-face)
 225
 226 (defface diff-changed-face
 227   '((((type tty pc) (class color) (background light))
 228      (:foreground "magenta" :bold t :italic t))
 229     (((type tty pc) (class color) (background dark))
 230      (:foreground "yellow" :bold t :italic t))
 231     (t ()))
 232   "`diff-mode' face used to highlight changed lines."
 233   :group 'diff-mode)
 234 (defvar diff-changed-face 'diff-changed-face)
 235
 236 (defface diff-function-face
 237   '((t (:inherit diff-context-face)))
 238   "`diff-mode' face used to highlight function names produced by \"diff -p\"."
 239   :group 'diff-mode)
 240 (defvar diff-function-face 'diff-function-face)
 241
 242 (defface diff-context-face
 243   '((((class color) (background light))
 244      (:foreground "grey50"))
 245     (((class color) (background dark))
 246      (:foreground "grey70"))
 247     (t ))
 248   "`diff-mode' face used to highlight context and other side-information."
 249   :group 'diff-mode)
 250 (defvar diff-context-face 'diff-context-face)
 251
 252 (defface diff-nonexistant-face
 253   '((t (:inherit diff-file-header-face)))
 254   "`diff-mode' face used to highlight nonexistant files in recursive diffs."
 255   :group 'diff-mode)
 256 (defvar diff-nonexistant-face 'diff-nonexistant-face)
 257
 258 (defvar diff-font-lock-keywords
 259   '(("^\\(@@ -[0-9,]+ \\+[0-9,]+ @@\\)\\(.*\\)$" ;unified
 260      (1 diff-hunk-header-face)
 261      (2 diff-function-face))
 262     ("^--- .+ ----$" . diff-hunk-header-face) ;context
 263     ("\\(\\*\\{15\\}\\)\\(.*\\)$"       ;context
 264      (1 diff-hunk-header-face)
 265      (2 diff-function-face))
 266     ("^\\*\\*\\* .+ \\*\\*\\*\\*". diff-hunk-header-face) ;context
 267     ("^\\(---\\|\\+\\+\\+\\|\\*\\*\\*\\) \\(\\S-+\\)\\(.*[^*-]\\)?\n"
 268      (0 diff-header-face) (2 diff-file-header-face prepend))
 269     ("^[0-9,]+[acd][0-9,]+$" . diff-hunk-header-face)
 270     ("^!.*\n" . diff-changed-face)      ;context
 271     ("^[+>].*\n" . diff-added-face)
 272     ("^[-<].*\n" . diff-removed-face)
 273     ("^Index: \\(.+\\).*\n" (0 diff-header-face) (1 diff-index-face prepend))
 274     ("^Only in .*\n" . diff-nonexistant-face)
 275     ("^#.*" . font-lock-string-face)
 276     ("^[^-=+*!<>].*\n" . diff-context-face)))
 277
 278 (defconst diff-font-lock-defaults
 279   '(diff-font-lock-keywords t nil nil nil (font-lock-multiline . nil)))
 280
 281 (defvar diff-imenu-generic-expression
 282   ;; Prefer second name as first is most likely to be a backup or
 283   ;; version-control name.  The [\t\n] at the end of the unidiff pattern
 284   ;; catches Debian source diff files (which lack the trailing date).
 285   '((nil "\\+\\+\\+\\ \\([^\t\n]+\\)[\t\n]" 1) ; unidiffs
 286     (nil "^--- \\([^\t\n]+\\)\t.*\n\\*" 1))) ; context diffs
 287
 288 ;;;;
 289 ;;;; Compile support
 290 ;;;;
 291
 292 (defvar diff-file-regexp-alist
 293   '(("Index: \\(.+\\)" 1)))
 294
 295 (defvar diff-error-regexp-alist
 296   '(("@@ -\\([0-9]+\\),[0-9]+ \\+\\([0-9]+\\),[0-9]+ @@" nil 2)
 297     ("--- \\([0-9]+\\),[0-9]+ ----" nil 1)
 298     ("\\([0-9]+\\)\\(,[0-9]+\\)?[adc]\\([0-9]+\\)" nil 3)))
 299
 300 ;;;;
 301 ;;;; Movement
 302 ;;;;
 303
 304 (defconst diff-hunk-header-re "^\\(@@ -[0-9,]+ \\+[0-9,]+ @@.*\\|\\*\\{15\\}.*\n\\*\\*\\* .+ \\*\\*\\*\\*\\|[0-9]+\\(,[0-9]+\\)?[acd][0-9]+\\(,[0-9]+\\)?\\)$")
 305 (defconst diff-file-header-re (concat "^\\(--- .+\n\\+\\+\\+\\|\\*\\*\\* .+\n---\\|[^-+!<>0-9@* ]\\).+\n" (substring diff-hunk-header-re 1)))
 306 (defvar diff-narrowed-to nil)
 307
 308 (defun diff-end-of-hunk (&optional style)
 309   (if (looking-at diff-hunk-header-re) (goto-char (match-end 0)))
 310   (let ((end (and (re-search-forward (case style
 311                                        (unified "^[^-+# \\]")
 312                                        (context "^[^-+#! \\]")
 313                                        (normal "^[^<>#\\]")
 314                                        (t "^[^-+#!<> \\]"))
 315                                      nil t)
 316                   (match-beginning 0))))
 317     ;; The return value is used by easy-mmode-define-navigation.
 318     (goto-char (or end (point-max)))))
 319
 320 (defun diff-beginning-of-hunk ()
 321   (beginning-of-line)
 322   (unless (looking-at diff-hunk-header-re)
 323     (forward-line 1)
 324     (condition-case ()
 325         (re-search-backward diff-hunk-header-re)
 326       (error (error "Can't find the beginning of the hunk")))))
 327
 328 (defun diff-beginning-of-file ()
 329   (beginning-of-line)
 330   (unless (looking-at diff-file-header-re)
 331     (forward-line 2)
 332     (condition-case ()
 333         (re-search-backward diff-file-header-re)
 334       (error (error "Can't find the beginning of the file")))))
 335
 336 (defun diff-end-of-file ()
 337   (re-search-forward "^[-+#!<>0-9@* \\]" nil t)
 338   (re-search-forward "^[^-+#!<>0-9@* \\]" nil 'move)
 339   (beginning-of-line))
 340
 341 ;; Define diff-{hunk,file}-{prev,next}
 342 (easy-mmode-define-navigation
 343  diff-hunk diff-hunk-header-re "hunk" diff-end-of-hunk)
 344 (easy-mmode-define-navigation
 345  diff-file diff-file-header-re "file" diff-end-of-hunk)
 346
 347 (defun diff-restrict-view (&optional arg)
 348   "Restrict the view to the current hunk.
 349 If the prefix ARG is given, restrict the view to the current file instead."
 350   (interactive "P")
 351   (save-excursion
 352     (if arg (diff-beginning-of-file) (diff-beginning-of-hunk))
 353     (narrow-to-region (point)
 354                       (progn (if arg (diff-end-of-file) (diff-end-of-hunk))
 355                              (point)))
 356     (set (make-local-variable 'diff-narrowed-to) (if arg 'file 'hunk))))
 357
 358
 359 (defun diff-hunk-kill ()
 360   "Kill current hunk."
 361   (interactive)
 362   (diff-beginning-of-hunk)
 363   (let ((start (point))
 364         (firsthunk (save-excursion
 365                      (ignore-errors
 366                        (diff-beginning-of-file) (diff-hunk-next) (point))))
 367         (nexthunk  (save-excursion
 368                      (ignore-errors
 369                        (diff-hunk-next) (point))))
 370         (nextfile (save-excursion
 371                     (ignore-errors
 372                       (diff-file-next) (point)))))
 373     (if (and firsthunk (= firsthunk start)
 374              (or (null nexthunk)
 375                  (and nextfile (> nexthunk nextfile))))
 376         ;; we're the only hunk for this file, so kill the file
 377         (diff-file-kill)
 378       (diff-end-of-hunk)
 379       (kill-region start (point)))))
 380
 381 (defun diff-file-kill ()
 382   "Kill current file's hunks."
 383   (interactive)
 384   (diff-beginning-of-file)
 385   (let* ((start (point))
 386          (prevhunk (save-excursion
 387                      (ignore-errors
 388                        (diff-hunk-prev) (point))))
 389          (index (save-excursion
 390                   (re-search-backward "^Index: " prevhunk t))))
 391     (when index (setq start index))
 392     (diff-end-of-file)
 393     (kill-region start (point))))
 394
 395 (defun diff-kill-junk ()
 396   "Kill spurious empty diffs."
 397   (interactive)
 398   (save-excursion
 399     (let ((inhibit-read-only t))
 400       (goto-char (point-min))
 401       (while (re-search-forward (concat "^\\(Index: .*\n\\)"
 402                                         "\\([^-+!* <>].*\n\\)*?"
 403                                         "\\(\\(Index:\\) \\|"
 404                                         diff-file-header-re "\\)")
 405                                 nil t)
 406         (delete-region (if (match-end 4) (match-beginning 0) (match-end 1))
 407                        (match-beginning 3))
 408         (beginning-of-line)))))
 409
 410 (defun diff-count-matches (re start end)
 411   (save-excursion
 412     (let ((n 0))
 413       (goto-char start)
 414       (while (re-search-forward re end t) (incf n))
 415       n)))
 416
 417 (defun diff-split-hunk ()
 418   "Split the current (unified diff) hunk at point into two hunks."
 419   (interactive)
 420   (beginning-of-line)
 421   (let ((pos (point))
 422         (start (progn (diff-beginning-of-hunk) (point))))
 423     (unless (looking-at "@@ -\\([0-9]+\\),[0-9]+ \\+\\([0-9]+\\),[0-9]+ @@")
 424       (error "diff-split-hunk only works on unified context diffs"))
 425     (forward-line 1)
 426     (let* ((start1 (string-to-number (match-string 1)))
 427            (start2 (string-to-number (match-string 2)))
 428            (newstart1 (+ start1 (diff-count-matches "^[- \t]" (point) pos)))
 429            (newstart2 (+ start2 (diff-count-matches "^[+ \t]" (point) pos))))
 430       (goto-char pos)
 431       ;; Hopefully the after-change-function will not screw us over.
 432       (insert "@@ -" (number-to-string newstart1) ",1 +"
 433               (number-to-string newstart2) ",1 @@\n")
 434       ;; Fix the original hunk-header.
 435       (diff-fixup-modifs start pos))))
 436
 437
 438 ;;;;
 439 ;;;; jump to other buffers
 440 ;;;;
 441
 442 (defvar diff-remembered-files-alist nil)
 443
 444 (defun diff-filename-drop-dir (file)
 445   (when (string-match "/" file) (substring file (match-end 0))))
 446
 447 (defun diff-merge-strings (ancestor from to)
 448   "Merge the diff between ANCESTOR and FROM into TO.
 449 Returns the merged string if successful or nil otherwise.
 450 The strings are assumed not to contain any \"\\n\" (i.e. end of line).
 451 If ANCESTOR = FROM, returns TO.
 452 If ANCESTOR = TO, returns FROM.
 453 The heuristic is simplistic and only really works for cases
 454 like \(diff-merge-strings \"b/foo\" \"b/bar\" \"/a/c/foo\")."
 455   ;; Ideally, we want:
 456   ;;   AMB ANB CMD -> CND
 457   ;; but that's ambiguous if `foo' or `bar' is empty:
 458   ;; a/foo a/foo1 b/foo.c -> b/foo1.c but not 1b/foo.c or b/foo.c1
 459   (let ((str (concat ancestor "\n" from "\n" to)))
 460     (when (and (string-match (concat
 461                               "\\`\\(.*?\\)\\(.*\\)\\(.*\\)\n"
 462                               "\\1\\(.*\\)\\3\n"
 463                               "\\(.*\\(\\2\\).*\\)\\'") str)
 464                (equal to (match-string 5 str)))
 465       (concat (substring str (match-beginning 5) (match-beginning 6))
 466               (match-string 4 str)
 467               (substring str (match-end 6) (match-end 5))))))
 468
 469 (defun diff-find-file-name (&optional old)
 470   "Return the file corresponding to the current patch.
 471 Non-nil OLD means that we want the old file."
 472   (save-excursion
 473     (unless (looking-at diff-file-header-re)
 474       (or (ignore-errors (diff-beginning-of-file))
 475           (re-search-forward diff-file-header-re nil t)))
 476     (let* ((limit (save-excursion
 477                    (condition-case ()
 478                        (progn (diff-hunk-prev) (point))
 479                      (error (point-min)))))
 480            (header-files
 481             (if (looking-at "[-*][-*][-*] \\(\\S-+\\)\\(\\s-.*\\)?\n[-+][-+][-+] \\(\\S-+\\)")
 482                 (list (if old (match-string 1) (match-string 3))
 483                       (if old (match-string 3) (match-string 1)))
 484               (forward-line 1) nil))
 485            (fs (append
 486                 (when (save-excursion
 487                         (re-search-backward "^Index: \\(.+\\)" limit t))
 488                   (list (match-string 1)))
 489                 header-files
 490                 (when (re-search-backward "^diff \\(-\\S-+ +\\)*\\(\\S-+\\)\\( +\\(\\S-+\\)\\)?" nil t)
 491                   (list (if old (match-string 2) (match-string 4))
 492                         (if old (match-string 4) (match-string 2))))))
 493            (fs (delq nil fs)))
 494       (or
 495        ;; use any previously used preference
 496        (cdr (assoc fs diff-remembered-files-alist))
 497        ;; try to be clever and use previous choices as an inspiration
 498        (dolist (rf diff-remembered-files-alist)
 499          (let ((newfile (diff-merge-strings (caar rf) (car fs) (cdr rf))))
 500            (if (and newfile (file-exists-p newfile)) (return newfile))))
 501        ;; look for each file in turn.  If none found, try again but
 502        ;; ignoring the first level of directory, ...
 503        (do* ((files fs (delq nil (mapcar 'diff-filename-drop-dir files)))
 504              (file nil nil))
 505            ((or (null files)
 506                 (setq file (do* ((files files (cdr files))
 507                                  (file (car files) (car files)))
 508                                ((or (null file) (file-exists-p file))
 509                                 file))))
 510             file))
 511        ;; <foo>.rej patches implicitly apply to <foo>
 512        (and (string-match "\\.rej\\'" (or buffer-file-name ""))
 513             (let ((file (substring buffer-file-name 0 (match-beginning 0))))
 514               (when (file-exists-p file) file)))
 515        ;; if all else fails, ask the user
 516        (let ((file (read-file-name (format "Use file %s: " (or (first fs) ""))
 517                                    nil (first fs) t (first fs))))
 518          (set (make-local-variable 'diff-remembered-files-alist)
 519               (cons (cons fs file) diff-remembered-files-alist))
 520          file)))))
 521
 522
 523 (defun diff-mouse-goto-source (event)
 524   "Run `diff-goto-source' for the diff at a mouse click."
 525   (interactive "e")
 526   (save-excursion
 527     (mouse-set-point event)
 528     (diff-goto-source)))
 529
 530
 531 (defun diff-ediff-patch ()
 532   "Call `ediff-patch-file' on the current buffer."
 533   (interactive)
 534   (condition-case err
 535       (ediff-patch-file nil (current-buffer))
 536     (wrong-number-of-arguments (ediff-patch-file))))
 537
 538 ;;;;
 539 ;;;; Conversion functions
 540 ;;;;
 541
 542 ;;(defvar diff-inhibit-after-change nil
 543 ;;  "Non-nil means inhibit `diff-mode's after-change functions.")
 544
 545 (defun diff-unified->context (start end)
 546   "Convert unified diffs to context diffs.
 547 START and END are either taken from the region (if a prefix arg is given) or
 548 else cover the whole bufer."
 549   (interactive (if current-prefix-arg
 550                    (list (mark) (point))
 551                  (list (point-min) (point-max))))
 552   (unless (markerp end) (setq end (copy-marker end)))
 553   (let (;;(diff-inhibit-after-change t)
 554         (inhibit-read-only t))
 555     (save-excursion
 556       (goto-char start)
 557       (while (and (re-search-forward "^\\(\\(---\\) .+\n\\(\\+\\+\\+\\) .+\\|@@ -\\([0-9]+\\),\\([0-9]+\\) \\+\\([0-9]+\\),\\([0-9]+\\) @@.*\\)$" nil t)
 558                   (< (point) end))
 559         (combine-after-change-calls
 560           (if (match-beginning 2)
 561               ;; we matched a file header
 562               (progn
 563                 ;; use reverse order to make sure the indices are kept valid
 564                 (replace-match "---" t t nil 3)
 565                 (replace-match "***" t t nil 2))
 566             ;; we matched a hunk header
 567             (let ((line1 (match-string 4))
 568                   (lines1 (match-string 5))
 569                   (line2 (match-string 6))
 570                   (lines2 (match-string 7)))
 571               (replace-match
 572                (concat "***************\n*** " line1 ","
 573                        (number-to-string (+ (string-to-number line1)
 574                                             (string-to-number lines1)
 575                                             -1)) " ****"))
 576               (forward-line 1)
 577               (save-restriction
 578                 (narrow-to-region (point)
 579                                   (progn (diff-end-of-hunk 'unified) (point)))
 580                 (let ((hunk (buffer-string)))
 581                   (goto-char (point-min))
 582                   (if (not (save-excursion (re-search-forward "^-" nil t)))
 583                       (delete-region (point) (point-max))
 584                     (goto-char (point-max))
 585                     (let ((modif nil) last-pt)
 586                       (while (progn (setq last-pt (point))
 587                                     (= (forward-line -1) 0))
 588                         (case (char-after)
 589                           (?  (insert " ") (setq modif nil) (backward-char 1))
 590                           (?+ (delete-region (point) last-pt) (setq modif t))
 591                           (?- (if (not modif)
 592                                   (progn (forward-char 1)
 593                                          (insert " "))
 594                                 (delete-char 1)
 595                                 (insert "! "))
 596                               (backward-char 2))
 597                           (?\\ (when (save-excursion (forward-line -1)
 598                                                      (= (char-after) ?+))
 599                                  (delete-region (point) last-pt) (setq modif t)))
 600                           (t (setq modif nil))))))
 601                   (goto-char (point-max))
 602                   (save-excursion
 603                     (insert "--- " line2 ","
 604                             (number-to-string (+ (string-to-number line2)
 605                                                  (string-to-number lines2)
 606                                                  -1)) " ----\n" hunk))
 607                   ;;(goto-char (point-min))
 608                   (forward-line 1)
 609                   (if (not (save-excursion (re-search-forward "^+" nil t)))
 610                       (delete-region (point) (point-max))
 611                     (let ((modif nil) (delete nil))
 612                       (while (not (eobp))
 613                         (case (char-after)
 614                           (?  (insert " ") (setq modif nil) (backward-char 1))
 615                           (?- (setq delete t) (setq modif t))
 616                           (?+ (if (not modif)
 617                                   (progn (forward-char 1)
 618                                          (insert " "))
 619                                 (delete-char 1)
 620                                 (insert "! "))
 621                               (backward-char 2))
 622                           (?\\ (when (save-excursion (forward-line 1)
 623                                                      (not (eobp)))
 624                                  (setq delete t) (setq modif t)))
 625                           (t (setq modif nil)))
 626                         (let ((last-pt (point)))
 627                           (forward-line 1)
 628                           (when delete
 629                             (delete-region last-pt (point))
 630                             (setq delete nil)))))))))))))))
 631
 632 (defun diff-context->unified (start end)
 633   "Convert context diffs to unified diffs.
 634 START and END are either taken from the region (if a prefix arg is given) or
 635 else cover the whole bufer."
 636   (interactive (if current-prefix-arg
 637                    (list (mark) (point))
 638                  (list (point-min) (point-max))))
 639   (unless (markerp end) (setq end (copy-marker end)))
 640   (let (;;(diff-inhibit-after-change t)
 641         (inhibit-read-only t))
 642     (save-excursion
 643       (goto-char start)
 644       (while (and (re-search-forward "^\\(\\(\\*\\*\\*\\) .+\n\\(---\\) .+\\|\\*\\{15\\}.*\n\\*\\*\\* \\([0-9]+\\),\\(-?[0-9]+\\) \\*\\*\\*\\*\\)$" nil t)
 645                   (< (point) end))
 646         (combine-after-change-calls
 647           (if (match-beginning 2)
 648               ;; we matched a file header
 649               (progn
 650                 ;; use reverse order to make sure the indices are kept valid
 651                 (replace-match "+++" t t nil 3)
 652                 (replace-match "---" t t nil 2))
 653             ;; we matched a hunk header
 654             (let ((line1s (match-string 4))
 655                   (line1e (match-string 5))
 656                   (pt1 (match-beginning 0)))
 657               (replace-match "")
 658               (unless (re-search-forward
 659                        "^--- \\([0-9]+\\),\\(-?[0-9]+\\) ----$" nil t)
 660                 (error "Can't find matching `--- n1,n2 ----' line"))
 661               (let ((line2s (match-string 1))
 662                     (line2e (match-string 2))
 663                     (pt2 (progn
 664                            (delete-region (progn (beginning-of-line) (point))
 665                                           (progn (forward-line 1) (point)))
 666                            (point-marker))))
 667                 (goto-char pt1)
 668                 (forward-line 1)
 669                 (while (< (point) pt2)
 670                   (case (char-after)
 671                     ((?! ?-) (delete-char 2) (insert "-") (forward-line 1))
 672                     (?\                 ;merge with the other half of the chunk
 673                      (let* ((endline2
 674                              (save-excursion
 675                                (goto-char pt2) (forward-line 1) (point)))
 676                             (c (char-after pt2)))
 677                        (case c
 678                          ((?! ?+)
 679                           (insert "+"
 680                                   (prog1 (buffer-substring (+ pt2 2) endline2)
 681                                     (delete-region pt2 endline2))))
 682                          (?\            ;FIXME: check consistency
 683                           (delete-region pt2 endline2)
 684                           (delete-char 1)
 685                           (forward-line 1))
 686                          (?\\ (forward-line 1))
 687                          (t (delete-char 1) (forward-line 1)))))
 688                     (t (forward-line 1))))
 689                 (while (looking-at "[+! ] ")
 690                   (if (/= (char-after) ?!) (forward-char 1)
 691                     (delete-char 1) (insert "+"))
 692                   (delete-char 1) (forward-line 1))
 693                 (save-excursion
 694                   (goto-char pt1)
 695                   (insert "@@ -" line1s ","
 696                           (number-to-string (- (string-to-number line1e)
 697                                                (string-to-number line1s)
 698                                                -1))
 699                           " +" line2s ","
 700                           (number-to-string (- (string-to-number line2e)
 701                                                (string-to-number line2s)
 702                                                -1)) " @@"))))))))))
 703
 704 (defun diff-reverse-direction (start end)
 705   "Reverse the direction of the diffs.
 706 START and END are either taken from the region (if a prefix arg is given) or
 707 else cover the whole bufer."
 708   (interactive (if current-prefix-arg
 709                    (list (mark) (point))
 710                  (list (point-min) (point-max))))
 711   (unless (markerp end) (setq end (copy-marker end)))
 712   (let (;;(diff-inhibit-after-change t)
 713         (inhibit-read-only t))
 714     (save-excursion
 715       (goto-char start)
 716       (while (and (re-search-forward "^\\(\\([-*][-*][-*] \\)\\(.+\\)\n\\([-+][-+][-+] \\)\\(.+\\)\\|\\*\\{15\\}.*\n\\*\\*\\* \\(.+\\) \\*\\*\\*\\*\\|@@ -\\([0-9,]+\\) \\+\\([0-9,]+\\) @@.*\\)$" nil t)
 717                   (< (point) end))
 718         (combine-after-change-calls
 719           (cond
 720            ;; a file header
 721            ((match-beginning 2) (replace-match "\\2\\5\n\\4\\3" nil))
 722            ;; a context-diff hunk header
 723            ((match-beginning 6)
 724             (let ((pt-lines1 (match-beginning 6))
 725                   (lines1 (match-string 6)))
 726               (replace-match "" nil nil nil 6)
 727               (forward-line 1)
 728               (let ((half1s (point)))
 729                 (while (looking-at "[-! \\][ \t]\\|#")
 730                   (when (= (char-after) ?-) (delete-char 1) (insert "+"))
 731                   (forward-line 1))
 732                 (let ((half1 (delete-and-extract-region half1s (point))))
 733                   (unless (looking-at "^--- \\([0-9]+,-?[0-9]+\\) ----$")
 734                     (insert half1)
 735                     (error "Can't find matching `--- n1,n2 ----' line"))
 736                   (let ((str1 (match-string 1)))
 737                     (replace-match lines1 nil nil nil 1)
 738                     (forward-line 1)
 739                     (let ((half2s (point)))
 740                       (while (looking-at "[!+ \\][ \t]\\|#")
 741                         (when (= (char-after) ?+) (delete-char 1) (insert "-"))
 742                         (forward-line 1))
 743                       (let ((half2 (delete-and-extract-region half2s (point))))
 744                         (insert (or half1 ""))
 745                         (goto-char half1s)
 746                         (insert (or half2 ""))))
 747                     (goto-char pt-lines1)
 748                     (insert str1))))))
 749            ;; a unified-diff hunk header
 750            ((match-beginning 7)
 751             (replace-match "@@ -\\8 +\\7 @@" nil)
 752             (forward-line 1)
 753             (let ((c (char-after)) first last)
 754               (while (case (setq c (char-after))
 755                        (?- (setq first (or first (point)))
 756                            (delete-char 1) (insert "+") t)
 757                        (?+ (setq last (or last (point)))
 758                            (delete-char 1) (insert "-") t)
 759                        ((?\\ ?#) t)
 760                        (t (when (and first last (< first last))
 761                             (let ((str
 762                                    (save-excursion
 763                                      (delete-and-extract-region first last))))
 764                               (insert str)))
 765                           (setq first nil last nil)
 766                           (equal ?\  c)))
 767                 (forward-line 1))))))))))
 768
 769 (defun diff-fixup-modifs (start end)
 770   "Fixup the hunk headers (in case the buffer was modified).
 771 START and END are either taken from the region (if a prefix arg is given) or
 772 else cover the whole bufer."
 773   (interactive (if current-prefix-arg
 774                    (list (mark) (point))
 775                  (list (point-min) (point-max))))
 776   (let ((inhibit-read-only t))
 777     (save-excursion
 778       (goto-char end) (diff-end-of-hunk)
 779       (let ((plus 0) (minus 0) (space 0) (bang 0))
 780         (while (and (= (forward-line -1) 0) (<= start (point)))
 781           (if (not (looking-at "\\(@@ -[0-9,]+ \\+[0-9,]+ @@.*\\|[-*][-*][-*] .+ [-*][-*][-*][-*]\\)$"))
 782               (case (char-after)
 783                 (?\  (incf space))
 784                 (?+ (incf plus))
 785                 (?- (incf minus))
 786                 (?! (incf bang))
 787                 ((?\\ ?#) nil)
 788                 (t  (setq space 0 plus 0 minus 0 bang 0)))
 789             (cond
 790              ((looking-at "@@ -[0-9]+,\\([0-9]*\\) \\+[0-9]+,\\([0-9]*\\) @@.*$")
 791               (let* ((old1 (match-string 1))
 792                      (old2 (match-string 2))
 793                      (new1 (number-to-string (+ space minus)))
 794                      (new2 (number-to-string (+ space plus))))
 795                 (unless (string= new2 old2) (replace-match new2 t t nil 2))
 796                 (unless (string= new1 old1) (replace-match new1 t t nil 1))))
 797              ((looking-at "--- \\([0-9]+\\),\\([0-9]*\\) ----$")
 798               (when (> (+ space bang plus) 0)
 799                 (let* ((old1 (match-string 1))
 800                        (old2 (match-string 2))
 801                        (new (number-to-string
 802                              (+ space bang plus -1 (string-to-number old1)))))
 803                   (unless (string= new old2) (replace-match new t t nil 2)))))
 804              ((looking-at "\\*\\*\\* \\([0-9]+\\),\\(-?[0-9]*\\) \\*\\*\\*\\*$")
 805               (when (> (+ space bang minus) 0)
 806                 (let* ((old (match-string 1))
 807                        (new (format
 808                              (concat "%0" (number-to-string (length old)) "d")
 809                              (+ space bang minus -1 (string-to-number old)))))
 810                   (unless (string= new old) (replace-match new t t nil 2))))))
 811             (setq space 0 plus 0 minus 0 bang 0)))))))
 812
 813 ;;;;
 814 ;;;; Hooks
 815 ;;;;
 816
 817 (defun diff-write-contents-hooks ()
 818   "Fixup hunk headers if necessary."
 819   (if (buffer-modified-p) (diff-fixup-modifs (point-min) (point-max)))
 820   nil)
 821
 822 ;; It turns out that making changes in the buffer from within an
 823 ;; *-change-function is asking for trouble, whereas making them
 824 ;; from a post-command-hook doesn't pose much problems
 825 (defvar diff-unhandled-changes nil)
 826 (defun diff-after-change-function (beg end len)
 827   "Remember to fixup the hunk header.
 828 See `after-change-functions' for the meaning of BEG, END and LEN."
 829   ;; Ignoring changes when inhibit-read-only is set is strictly speaking
 830   ;; incorrect, but it turns out that inhibit-read-only is normally not set
 831   ;; inside editing commands, while it tends to be set when the buffer gets
 832   ;; updated by an async process or by a conversion function, both of which
 833   ;; would rather not be uselessly slowed down by this hook.
 834   (when (and (not undo-in-progress) (not inhibit-read-only))
 835     (if diff-unhandled-changes
 836         (setq diff-unhandled-changes
 837               (cons (min beg (car diff-unhandled-changes))
 838                     (max beg (cdr diff-unhandled-changes))))
 839       (setq diff-unhandled-changes (cons beg end)))))
 840
 841 (defun diff-post-command-hook ()
 842   "Fixup hunk headers if necessary."
 843   (when (consp diff-unhandled-changes)
 844     (ignore-errors
 845       (save-excursion
 846         (goto-char (car diff-unhandled-changes))
 847         (unless (ignore-errors
 848                   (diff-beginning-of-hunk)
 849                   (save-excursion
 850                     (diff-end-of-hunk)
 851                     (> (point) (car diff-unhandled-changes))))
 852           (goto-char (car diff-unhandled-changes))
 853           (re-search-forward diff-hunk-header-re (cdr diff-unhandled-changes))
 854           (diff-beginning-of-hunk))
 855         (diff-fixup-modifs (point) (cdr diff-unhandled-changes))))
 856     (setq diff-unhandled-changes nil)))
 857
 858 ;;;;
 859 ;;;; The main function
 860 ;;;;
 861
 862 ;;;###autoload
 863 (define-derived-mode diff-mode fundamental-mode "Diff"
 864   "Major mode for viewing/editing context diffs.
 865 Supports unified and context diffs as well as (to a lesser extent) normal diffs.
 866 When the buffer is read-only, the ESC prefix is not necessary.
 867 This mode runs `diff-mode-hook'.
 868 \\{diff-mode-map}"
 869   (set (make-local-variable 'font-lock-defaults) diff-font-lock-defaults)
 870   (set (make-local-variable 'outline-regexp) diff-outline-regexp)
 871   (set (make-local-variable 'imenu-generic-expression)
 872        diff-imenu-generic-expression)
 873   ;; These are not perfect.  They would be better done separately for
 874   ;; context diffs and unidiffs.
 875   ;; (set (make-local-variable 'paragraph-start)
 876   ;;        (concat "@@ "                       ; unidiff hunk
 877   ;;           "\\|\\*\\*\\* "          ; context diff hunk or file start
 878   ;;           "\\|--- [^\t]+\t"))      ; context or unidiff file
 879   ;;                                    ; start (first or second line)
 880   ;;   (set (make-local-variable 'paragraph-separate) paragraph-start)
 881   ;;   (set (make-local-variable 'page-delimiter) "--- [^\t]+\t")
 882   ;; compile support
 883
 884   ;;;; compile support is not good enough yet.  Also it can be annoying
 885   ;; and should thus only be enabled conditionally.
 886   ;; (set (make-local-variable 'compilation-file-regexp-alist)
 887   ;;      diff-file-regexp-alist)
 888   ;; (set (make-local-variable 'compilation-error-regexp-alist)
 889   ;;      diff-error-regexp-alist)
 890   ;; (when (string-match "\\.rej\\'" (or buffer-file-name ""))
 891   ;;   (set (make-local-variable 'compilation-current-file)
 892   ;;     (substring buffer-file-name 0 (match-beginning 0))))
 893   ;; (compilation-shell-minor-mode 1)
 894
 895   ;; setup change hooks
 896   (toggle-read-only t)
 897   (if (not diff-update-on-the-fly-flag)
 898       (add-hook 'write-contents-hooks 'diff-write-contents-hooks)
 899     (make-local-variable 'diff-unhandled-changes)
 900     (add-hook 'after-change-functions 'diff-after-change-function nil t)
 901     (add-hook 'post-command-hook 'diff-post-command-hook nil t))
 902   ;; Neat trick from Dave Love to add more bindings in read-only mode:
 903   (add-to-list (make-local-variable 'minor-mode-overriding-map-alist)
 904                (cons 'buffer-read-only diff-mode-shared-map))
 905   ;; add-log support
 906   (set (make-local-variable 'add-log-current-defun-function)
 907        'diff-current-defun)
 908   (set (make-local-variable 'add-log-buffer-file-name-function)
 909        'diff-find-file-name))
 910
 911 ;;;###autoload
 912 (define-minor-mode diff-minor-mode
 913   "Minor mode for viewing/editing context diffs.
 914 \\{diff-minor-mode-map}"
 915   nil " Diff" nil
 916   ;; FIXME: setup font-lock
 917   ;; setup change hooks
 918   (if (not diff-update-on-the-fly-flag)
 919       (add-hook 'write-contents-hooks 'diff-write-contents-hooks)
 920     (make-local-variable 'diff-unhandled-changes)
 921     (add-hook 'after-change-functions 'diff-after-change-function nil t)
 922     (add-hook 'post-command-hook 'diff-post-command-hook nil t)))
 923
 924
 925 ;;;
 926 ;;; Misc operations that have proved useful at some point.
 927 ;;;
 928
 929 (defun diff-next-complex-hunk ()
 930   "Jump to the next \"complex\" hunk.
 931 \"Complex\" is approximated by \"the hunk changes the number of lines\".
 932 Only works for unified diffs."
 933   (interactive)
 934   (while
 935       (and (re-search-forward "^@@ [-0-9]+,\\([0-9]+\\) [+0-9]+,\\([0-9]+\\) @@"
 936                               nil t)
 937            (equal (match-string 1) (match-string 2)))))
 938
 939 (defun diff-hunk-text (hunk destp &optional char-offset)
 940   "Return the literal source text from HUNK.
 941 if DESTP is nil return the source, otherwise the destination text.
 942 If CHAR-OFFSET is non-nil, it should be a char-offset in
 943 HUNK, and instead of a string, a cons cell is returned whose car is the
 944 appropriate text, and whose cdr is the corresponding char-offset in that text."
 945   (with-temp-buffer
 946     (insert hunk)
 947     (goto-char (point-min))
 948     (let ((src-pos nil)
 949           (dst-pos nil)
 950           (divider-pos nil)
 951           (num-pfx-chars 2))
 952       ;; Set the following variables:
 953       ;;  SRC-POS     buffer pos of the source part of the hunk or nil if none
 954       ;;  DST-POS     buffer pos of the destination part of the hunk or nil
 955       ;;  DIVIDER-POS buffer pos of any divider line separating the src & dst
 956       ;;  NUM-PFX-CHARS  number of line-prefix characters used by this format"
 957       (cond ((looking-at "^@@")
 958              ;; unified diff
 959              (setq num-pfx-chars 1)
 960              (forward-line 1)
 961              (setq src-pos (point) dst-pos (point)))
 962             ((looking-at "^\\*\\*")
 963              ;; context diff
 964              (forward-line 2)
 965              (setq src-pos (point))
 966              (re-search-forward "^--- " nil t)
 967              (forward-line 0)
 968              (setq divider-pos (point))
 969              (forward-line 1)
 970              (setq dst-pos (point)))
 971             ((looking-at "^[0-9]+a[0-9,]+$")
 972              ;; normal diff, insert
 973              (forward-line 1)
 974              (setq dst-pos (point)))
 975             ((looking-at "^[0-9,]+d[0-9]+$")
 976              ;; normal diff, delete
 977              (forward-line 1)
 978              (setq src-pos (point)))
 979             ((looking-at "^[0-9,]+c[0-9,]+$")
 980              ;; normal diff, change
 981              (forward-line 1)
 982              (setq src-pos (point))
 983              (re-search-forward "^---$" nil t)
 984              (forward-line 0)
 985              (setq divider-pos (point))
 986              (forward-line 1)
 987              (setq dst-pos (point)))
 988             (t
 989              (error "Unknown diff hunk type")))
 990
 991       (if (if destp (null dst-pos) (null src-pos))
 992           ;; Implied empty text
 993           (if char-offset '("" . 0) "")
 994
 995         ;; For context diffs, either side can be empty, (if there's only
 996         ;; added or only removed text).  We should then use the other side.
 997         (cond ((equal src-pos divider-pos) (setq src-pos dst-pos))
 998               ((equal dst-pos (point-max)) (setq dst-pos src-pos)))
 999
1000         (when char-offset (goto-char (+ (point-min) char-offset)))
1001
1002         ;; Get rid of anything except the desired text.
1003         (save-excursion
1004           ;; Delete unused text region
1005           (let ((keep (if destp dst-pos src-pos)))
1006             (when (and divider-pos (> divider-pos keep))
1007               (delete-region divider-pos (point-max)))
1008             (delete-region (point-min) keep))
1009           ;; Remove line-prefix characters, and unneeded lines (unified diffs).
1010           (let ((kill-char (if destp ?- ?+)))
1011             (goto-char (point-min))
1012             (while (not (eobp))
1013               (if (eq (char-after) kill-char)
1014                   (delete-region (point) (progn (forward-line 1) (point)))
1015                 (delete-char num-pfx-chars)
1016                 (forward-line 1)))))
1017
1018         (let ((text (buffer-substring-no-properties (point-min) (point-max))))
1019           (if char-offset (cons text (- (point) (point-min))) text))))))
1020
1021
1022 (defun diff-find-text (text)
1023   "Return the buffer position of the nearest occurrence of TEXT.
1024 If TEXT isn't found, nil is returned."
1025   (let* ((orig (point))
1026          (forw (and (search-forward text nil t)
1027                           (match-beginning 0)))
1028          (back (and (goto-char (+ orig (length text)))
1029                     (search-backward text nil t)
1030                           (match-beginning 0))))
1031           ;; Choose the closest match.
1032     (if (and forw back)
1033         (if (> (- forw orig) (- orig back)) back forw)
1034       (or back forw))))
1035
1036 (defsubst diff-xor (a b) (if a (not b) b))
1037
1038 (defun diff-find-source-location (&optional other-file reverse)
1039   "Find out (BUF LINE-OFFSET POS SRC DST SWITCHED)."
1040   (save-excursion
1041     (let* ((other (diff-xor other-file diff-jump-to-old-file-flag))
1042            (char-offset (- (point) (progn (diff-beginning-of-hunk) (point))))
1043            (hunk (buffer-substring (point)
1044                                    (save-excursion (diff-end-of-hunk) (point))))
1045            (old (diff-hunk-text hunk reverse char-offset))
1046            (new (diff-hunk-text hunk (not reverse) char-offset))
1047            ;; Find the location specification.
1048            (line (if (not (looking-at "\\(?:\\*\\{15\\}.*\n\\)?[-@* ]*\\([0-9,]+\\)\\([ acd+]+\\([0-9,]+\\)\\)?"))
1049                      (error "Can't find the hunk header")
1050                    (if other (match-string 1)
1051                      (if (match-end 3) (match-string 3)
1052                        (unless (re-search-forward "^--- \\([0-9,]+\\)" nil t)
1053                          (error "Can't find the hunk separator"))
1054                        (match-string 1)))))
1055            (file (or (diff-find-file-name other) (error "Can't find the file")))
1056            (buf (find-file-noselect file)))
1057       ;; Update the user preference if he so wished.
1058       (when (> (prefix-numeric-value other-file) 8)
1059         (setq diff-jump-to-old-file-flag other))
1060       (with-current-buffer buf
1061         (goto-line (string-to-number line))
1062         (let* ((orig-pos (point))
1063                (pos (diff-find-text (car old)))
1064                (switched nil))
1065           (when (null pos)
1066             (setq pos (diff-find-text (car new)) switched t))
1067           (nconc
1068            (list buf)
1069            (if pos (list (count-lines orig-pos pos) pos) (list nil orig-pos))
1070            (if switched (list new old t) (list old new))))))))
1071
1072
1073 (defun diff-hunk-status-msg (line-offset reversed dry-run)
1074   (let ((msg (if dry-run
1075                  (if reversed "already applied" "not yet applied")
1076                (if reversed "undone" "applied"))))
1077     (message (cond ((null line-offset) "Hunk text not found")
1078                    ((= line-offset 0) "Hunk %s")
1079                    ((= line-offset 1) "Hunk %s at offset %d line")
1080                    (t "Hunk %s at offset %d lines"))
1081              msg line-offset)))
1082
1083
1084 (defun diff-apply-hunk (&optional reverse)
1085   "Apply the current hunk to the source file and go to the next.
1086 By default, the new source file is patched, but if the variable
1087 `diff-jump-to-old-file-flag' is non-nil, then the old source file is
1088 patched instead (some commands, such as `diff-goto-source' can change
1089 the value of this variable when given an appropriate prefix argument).
1090
1091 With a prefix argument, REVERSE the hunk."
1092   (interactive "P")
1093   (destructuring-bind (buf line-offset pos old new &optional switched)
1094       (diff-find-source-location nil reverse)
1095     (cond
1096      ((null line-offset)
1097       (error "Can't find the text to patch"))
1098      ((and switched
1099            ;; A reversed patch was detected, perhaps apply it in reverse.
1100            (not (save-window-excursion
1101                   (pop-to-buffer buf)
1102                   (goto-char (+ pos (cdr old)))
1103                   (y-or-n-p
1104                    (if reverse
1105                        "Hunk hasn't been applied yet; apply it now? "
1106                      "Hunk has already been applied; undo it? ")))))
1107       (message "(Nothing done)"))
1108      (t
1109       ;; Apply the hunk
1110       (with-current-buffer buf
1111         (goto-char pos)
1112         (delete-char (length (car old)))
1113         (insert (car new)))
1114       ;; Display BUF in a window
1115       (set-window-point (display-buffer buf) (+ pos (cdr new)))
1116       (diff-hunk-status-msg line-offset (diff-xor switched reverse) nil)
1117       (when diff-advance-after-apply-hunk
1118         (diff-hunk-next))))))
1119
1120
1121 (defun diff-test-hunk (&optional reverse)
1122   "See whether it's possible to apply the current hunk.
1123 With a prefix argument, try to REVERSE the hunk."
1124   (interactive "P")
1125   (destructuring-bind (buf line-offset pos src dst &optional switched)
1126       (diff-find-source-location nil reverse)
1127     (set-window-point (display-buffer buf) (+ pos (cdr src)))
1128     (diff-hunk-status-msg line-offset (diff-xor reverse switched) t)))
1129
1130
1131 (defun diff-goto-source (&optional other-file)
1132   "Jump to the corresponding source line.
1133 `diff-jump-to-old-file-flag' (or its opposite if the OTHER-FILE prefix arg
1134 is given) determines whether to jump to the old or the new file.
1135 If the prefix arg is bigger than 8 (for example with \\[universal-argument] \\[universal-argument])
1136   then `diff-jump-to-old-file-flag' is also set, for the next invocations."
1137   (interactive "P")
1138   ;; When pointing at a removal line, we probably want to jump to
1139   ;; the old location, and else to the new (i.e. as if reverting).
1140   ;; This is a convenient detail when using smerge-diff.
1141   (let ((rev (not (save-excursion (beginning-of-line) (looking-at "[-<]")))))
1142     (destructuring-bind (buf line-offset pos src dst &optional switched)
1143         (diff-find-source-location other-file rev)
1144       (pop-to-buffer buf)
1145       (goto-char (+ pos (cdr src)))
1146       (diff-hunk-status-msg line-offset (diff-xor rev switched) t))))
1147
1148
1149 (defun diff-current-defun ()
1150   "Find the name of function at point.
1151 For use in `add-log-current-defun-function'."
1152   (destructuring-bind (buf line-offset pos src dst &optional switched)
1153       (diff-find-source-location)
1154     (save-excursion
1155       (beginning-of-line)
1156       (or (when (memq (char-after) '(?< ?-))
1157             ;; Cursor is pointing at removed text.  This could be a removed
1158             ;; function, in which case, going to the source buffer will
1159             ;; not help since the function is now removed.  Instead,
1160             ;; try to figure out the function name just from the code-fragment.
1161             (let ((old (if switched dst src)))
1162               (with-temp-buffer
1163                 (insert (car old))
1164                 (goto-char (cdr old))
1165                 (funcall (with-current-buffer buf major-mode))
1166                 (add-log-current-defun))))
1167           (with-current-buffer buf
1168             (goto-char (+ pos (cdr src)))
1169             (add-log-current-defun))))))
1170
1171 ;; provide the package
1172 (provide 'diff-mode)
1173
1174 ;;; Old Change Log from when diff-mode wasn't part of Emacs:
1175 ;; Revision 1.11  1999/10/09 23:38:29  monnier
1176 ;; (diff-mode-load-hook): dropped.
1177 ;; (auto-mode-alist): also catch *.diffs.
1178 ;; (diff-find-file-name, diff-mode):  add smarts to find the right file
1179 ;;     for *.rej files (that lack any file name indication).
1180 ;;
1181 ;; Revision 1.10  1999/09/30 15:32:11  monnier
1182 ;; added support for "\ No newline at end of file".
1183 ;;
1184 ;; Revision 1.9  1999/09/15 00:01:13  monnier
1185 ;; - added basic `compile' support.
1186 ;; - have diff-kill-hunk call diff-kill-file if it's the only hunk.
1187 ;; - diff-kill-file now tries to kill the leading garbage as well.
1188 ;;
1189 ;; Revision 1.8  1999/09/13 21:10:09  monnier
1190 ;; - don't use CL in the autoloaded code
1191 ;; - accept diffs using -T
1192 ;;
1193 ;; Revision 1.7  1999/09/05 20:53:03  monnier
1194 ;; interface to ediff-patch
1195 ;;
1196 ;; Revision 1.6  1999/09/01 20:55:13  monnier
1197 ;; (ediff=patch-file):  add bindings to call ediff-patch.
1198 ;; (diff-find-file-name):  taken out of diff-goto-source.
1199 ;; (diff-unified->context, diff-context->unified, diff-reverse-direction,
1200 ;;  diff-fixup-modifs):  only use the region if a prefix arg is given.
1201 ;;
1202 ;; Revision 1.5  1999/08/31 19:18:52  monnier
1203 ;; (diff-beginning-of-file, diff-prev-file):  fixed wrong parenthesis.
1204 ;;
1205 ;; Revision 1.4  1999/08/31 13:01:44  monnier
1206 ;; use `combine-after-change-calls' to minimize the slowdown of font-lock.
1207 ;;
1208
1209 ;;; diff-mode.el ends here