diff-mode.el 70.4 KB
Newer Older
Pavel Janík's avatar
Pavel Janík committed
1
;;; diff-mode.el --- a mode for viewing/editing context diffs
2

3
;; Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004,
4
;;   2005, 2006, 2007, 2008 Free Software Foundation, Inc.
5

Stefan Monnier's avatar
Stefan Monnier committed
6
;; Author: Stefan Monnier <monnier@iro.umontreal.ca>
Pavel Janík's avatar
Pavel Janík committed
7
;; Keywords: convenience patch diff
8 9 10 11 12

;; This file is part of GNU Emacs.

;; GNU Emacs is free software; you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
13
;; the Free Software Foundation; either version 3, or (at your option)
14 15 16 17 18 19 20 21 22
;; any later version.

;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;; GNU General Public License for more details.

;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs; see the file COPYING.  If not, write to the
Lute Kamstra's avatar
Lute Kamstra committed
23 24
;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
;; Boston, MA 02110-1301, USA.
25 26 27

;;; Commentary:

28
;; Provides support for font-lock, outline, navigation
29 30 31
;; commands, editing and various conversions as well as jumping
;; to the corresponding source file.

32
;; Inspired by Pavel Machek's patch-mode.el (<pavel@@atrey.karlin.mff.cuni.cz>)
Pavel Janík's avatar
Pavel Janík committed
33
;; Some efforts were spent to have it somewhat compatible with XEmacs'
34 35 36 37
;; diff-mode as well as with compilation-minor-mode

;; Bugs:

38
;; - Reverse doesn't work with normal diffs.
39 40 41

;; Todo:

Dan Nicolaescu's avatar
Dan Nicolaescu committed
42 43
;; - Improve `diff-create-changelog', it is very simplistic now.
;;  
44 45 46 47 48 49 50
;; - Add a `delete-after-apply' so C-c C-a automatically deletes hunks.
;;   Also allow C-c C-a to delete already-applied hunks.
;;
;; - Try `diff <file> <hunk>' to try and fuzzily discover the source location
;;   of a hunk.  Show then the changes between <file> and <hunk> and make it
;;   possible to apply them to <file>, <hunk-src>, or <hunk-dst>.
;;   Or maybe just make it into a ".rej to diff3-markers converter".
51
;;   Maybe just use `wiggle' (by Neil Brown) to do it for us.
52
;;
53 54
;; - in diff-apply-hunk, strip context in replace-match to better
;;   preserve markers and spacing.
55
;; - Handle `diff -b' output in context->unified.
56 57 58 59

;;; Code:
(eval-when-compile (require 'cl))

60 61
(defvar add-log-buffer-file-name-function)

62 63

(defgroup diff-mode ()
64
  "Major mode for viewing/editing diffs."
65
  :version "21.1"
66 67 68
  :group 'tools
  :group 'diff)

69
(defcustom diff-default-read-only nil
70 71 72 73
  "If non-nil, `diff-mode' buffers default to being read-only."
  :type 'boolean
  :group 'diff-mode)

74
(defcustom diff-jump-to-old-file nil
75
  "Non-nil means `diff-goto-source' jumps to the old file.
76
Else, it jumps to the new file."
77 78
  :type 'boolean
  :group 'diff-mode)
79

80
(defcustom diff-update-on-the-fly t
81 82 83 84 85 86
  "*Non-nil means hunk headers are kept up-to-date on-the-fly.
When editing a diff file, the line numbers in the hunk headers
need to be kept consistent with the actual diff.  This can
either be done on the fly (but this sometimes interacts poorly with the
undo mechanism) or whenever the file is written (can be slow
when editing big diffs)."
87 88
  :type 'boolean
  :group 'diff-mode)
89

90 91
(defcustom diff-advance-after-apply-hunk t
  "*Non-nil means `diff-apply-hunk' will move to the next hunk after applying."
92 93
  :type 'boolean
  :group 'diff-mode)
94

Stefan Monnier's avatar
Stefan Monnier committed
95 96
(defcustom diff-auto-refine t
  "Automatically highlight changes in detail as the user visits hunks."
97 98
  :type 'boolean
  :group 'diff-mode)
99

100 101 102
(defcustom diff-mode-hook nil
  "Run after setting up the `diff-mode' major mode."
  :type 'hook
103 104
  :options '(diff-delete-empty-files diff-make-unified)
  :group 'diff-mode)
105 106 107 108

(defvar diff-outline-regexp
  "\\([*+][*+][*+] [^0-9]\\|@@ ...\\|\\*\\*\\* [0-9].\\|--- [0-9]..\\)")

109
;;;;
110
;;;; keymap, menu, ...
111
;;;;
112

113
(easy-mmode-defmap diff-mode-shared-map
114
  '(;; From Pavel Machek's patch-mode.
115 116 117 118
    ("n" . diff-hunk-next)
    ("N" . diff-file-next)
    ("p" . diff-hunk-prev)
    ("P" . diff-file-prev)
119 120
    ("\t" . diff-hunk-next)
    ([backtab] . diff-hunk-prev)
121 122
    ("k" . diff-hunk-kill)
    ("K" . diff-file-kill)
123
    ;; From compilation-minor-mode.
124 125
    ("}" . diff-file-next)
    ("{" . diff-file-prev)
126
    ("\C-m" . diff-goto-source)
127
    ([mouse-2] . diff-goto-source)
128
    ;; From XEmacs' diff-mode.
129 130
    ;; Standard M-w is useful, so don't change M-W.
    ;;("W" . widen)
131 132 133 134 135 136 137 138
    ;;("." . diff-goto-source)		;display-buffer
    ;;("f" . diff-goto-source)		;find-file
    ("o" . diff-goto-source)		;other-window
    ;;("w" . diff-goto-source)		;other-frame
    ;;("N" . diff-narrow)
    ;;("h" . diff-show-header)
    ;;("j" . diff-show-difference)	;jump to Nth diff
    ;;("q" . diff-quit)
139 140 141 142 143 144 145 146
    ;; Not useful if you have to metafy them.
    ;;(" " . scroll-up)
    ;;("\177" . scroll-down)
    ;; Standard M-a is useful, so don't change M-A.
    ;;("A" . diff-ediff-patch)
    ;; Standard M-r is useful, so don't change M-r or M-R.
    ;;("r" . diff-restrict-view)
    ;;("R" . diff-reverse-direction)
Benjamin Rutt's avatar
Benjamin Rutt committed
147
    ("q" . quit-window))
148
  "Basic keymap for `diff-mode', bound to various prefix keys.")
149

150
(easy-mmode-defmap diff-mode-map
151
  `(("\e" . ,diff-mode-shared-map)
152 153 154
    ;; From compilation-minor-mode.
    ("\C-c\C-c" . diff-goto-source)
    ;; Misc operations.
155
    ("\C-c\C-a" . diff-apply-hunk)
156 157 158
    ("\C-c\C-e" . diff-ediff-patch)
    ("\C-c\C-n" . diff-restrict-view)
    ("\C-c\C-s" . diff-split-hunk)
159
    ("\C-c\C-t" . diff-test-hunk)
Stefan Monnier's avatar
Stefan Monnier committed
160
    ("\C-c\C-r" . diff-reverse-direction)
161
    ("\C-c\C-u" . diff-context->unified)
162 163
    ;; `d' because it duplicates the context :-(  --Stef
    ("\C-c\C-d" . diff-unified->context)
Stefan Monnier's avatar
Stefan Monnier committed
164 165
    ("\C-c\C-w" . diff-ignore-whitespace-hunk)
    ("\C-c\C-b" . diff-refine-hunk)  ;No reason for `b' :-(
166
    ("\C-c\C-f" . next-error-follow-minor-mode))
167 168 169 170 171 172
  "Keymap for `diff-mode'.  See also `diff-mode-shared-map'.")

(easy-menu-define diff-mode-menu diff-mode-map
  "Menu for `diff-mode'."
  '("Diff"
    ["Jump to Source"		diff-goto-source	t]
173
    ["Apply hunk"		diff-apply-hunk		t]
Stefan Monnier's avatar
Stefan Monnier committed
174
    ["Test applying hunk"	diff-test-hunk		t]
175
    ["Apply diff with Ediff"	diff-ediff-patch	t]
Dan Nicolaescu's avatar
Dan Nicolaescu committed
176 177
    ["Create Change Log"        diff-create-changelog
     :help "Create ChangeLog entries for the changes in the diff buffer"]
Stefan Monnier's avatar
Stefan Monnier committed
178
    "-----"
179 180 181 182
    ["Reverse direction"	diff-reverse-direction	t]
    ["Context -> Unified"	diff-context->unified	t]
    ["Unified -> Context"	diff-unified->context	t]
    ;;["Fixup Headers"		diff-fixup-modifs	(not buffer-read-only)]
Stefan Monnier's avatar
Stefan Monnier committed
183
    "-----"
184
    ["Split hunk"		diff-split-hunk		(diff-splittable-p)]
Stefan Monnier's avatar
Stefan Monnier committed
185 186
    ["Ignore whitespace changes" diff-ignore-whitespace-hunk t]
    ["Highlight fine changes"	diff-refine-hunk	t]
Stefan Monnier's avatar
Stefan Monnier committed
187 188 189 190 191 192 193
    ["Kill current hunk"	diff-hunk-kill   	t]
    ["Kill current file's hunks" diff-file-kill   	t]
    "-----"
    ["Previous Hunk"		diff-hunk-prev  	t]
    ["Next Hunk"		diff-hunk-next  	t]
    ["Previous File"		diff-file-prev  	t]
    ["Next File"		diff-file-next  	t]
194 195
    ))

196
(defcustom diff-minor-mode-prefix "\C-c="
197
  "Prefix key for `diff-minor-mode' commands."
198 199
  :type '(choice (string "\e") (string "C-c=") string)
  :group 'diff-mode)
200

201 202
(easy-mmode-defmap diff-minor-mode-map
  `((,diff-minor-mode-prefix . ,diff-mode-shared-map))
203 204
  "Keymap for `diff-minor-mode'.  See also `diff-mode-shared-map'.")

205

206
;;;;
207
;;;; font-lock support
208
;;;;
209

210
(defface diff-header
211
  '((((class color) (min-colors 88) (background light))
212
     :background "grey85")
213
    (((class color) (min-colors 88) (background dark))
214
     :background "grey45")
215
    (((class color) (background light))
216
     :foreground "blue1" :weight bold)
217
    (((class color) (background dark))
218 219
     :foreground "green" :weight bold)
    (t :weight bold))
220 221
  "`diff-mode' face inherited by hunk and index header faces."
  :group 'diff-mode)
222 223 224
;; backward-compatibility alias
(put 'diff-header-face 'face-alias 'diff-header)
(defvar diff-header-face 'diff-header)
Stefan Monnier's avatar
Stefan Monnier committed
225

226
(defface diff-file-header
227
  '((((class color) (min-colors 88) (background light))
228
     :background "grey70" :weight bold)
229
    (((class color) (min-colors 88) (background dark))
230
     :background "grey60" :weight bold)
231
    (((class color) (background light))
232
     :foreground "green" :weight bold)
233
    (((class color) (background dark))
234 235
     :foreground "cyan" :weight bold)
    (t :weight bold))			; :height 1.3
236 237
  "`diff-mode' face used to highlight file header lines."
  :group 'diff-mode)
238 239 240
;; backward-compatibility alias
(put 'diff-file-header-face 'face-alias 'diff-file-header)
(defvar diff-file-header-face 'diff-file-header)
241

242 243
(defface diff-index
  '((t :inherit diff-file-header))
244 245
  "`diff-mode' face used to highlight index header lines."
  :group 'diff-mode)
246 247 248
;; backward-compatibility alias
(put 'diff-index-face 'face-alias 'diff-index)
(defvar diff-index-face 'diff-index)
249

250 251
(defface diff-hunk-header
  '((t :inherit diff-header))
252 253
  "`diff-mode' face used to highlight hunk header lines."
  :group 'diff-mode)
254 255 256
;; backward-compatibility alias
(put 'diff-hunk-header-face 'face-alias 'diff-hunk-header)
(defvar diff-hunk-header-face 'diff-hunk-header)
257

258 259
(defface diff-removed
  '((t :inherit diff-changed))
260 261
  "`diff-mode' face used to highlight removed lines."
  :group 'diff-mode)
262 263 264
;; backward-compatibility alias
(put 'diff-removed-face 'face-alias 'diff-removed)
(defvar diff-removed-face 'diff-removed)
265

266 267
(defface diff-added
  '((t :inherit diff-changed))
268 269
  "`diff-mode' face used to highlight added lines."
  :group 'diff-mode)
270 271 272
;; backward-compatibility alias
(put 'diff-added-face 'face-alias 'diff-added)
(defvar diff-added-face 'diff-added)
273

274
(defface diff-changed
275
  '((((type tty pc) (class color) (background light))
276
     :foreground "magenta" :weight bold :slant italic)
277
    (((type tty pc) (class color) (background dark))
278
     :foreground "yellow" :weight bold :slant italic))
279 280
  "`diff-mode' face used to highlight changed lines."
  :group 'diff-mode)
281 282 283
;; backward-compatibility alias
(put 'diff-changed-face 'face-alias 'diff-changed)
(defvar diff-changed-face 'diff-changed)
284

285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305
(defface diff-indicator-removed
  '((t :inherit diff-removed))
  "`diff-mode' face used to highlight indicator of removed lines (-, <)."
  :group 'diff-mode
  :version "22.1")
(defvar diff-indicator-removed-face 'diff-indicator-removed)

(defface diff-indicator-added
  '((t :inherit diff-added))
  "`diff-mode' face used to highlight indicator of added lines (+, >)."
  :group 'diff-mode
  :version "22.1")
(defvar diff-indicator-added-face 'diff-indicator-added)

(defface diff-indicator-changed
  '((t :inherit diff-changed))
  "`diff-mode' face used to highlight indicator of changed lines."
  :group 'diff-mode
  :version "22.1")
(defvar diff-indicator-changed-face 'diff-indicator-changed)

306
(defface diff-function
307
  '((t :inherit diff-header))
308 309
  "`diff-mode' face used to highlight function names produced by \"diff -p\"."
  :group 'diff-mode)
310 311 312
;; backward-compatibility alias
(put 'diff-function-face 'face-alias 'diff-function)
(defvar diff-function-face 'diff-function)
313

314
(defface diff-context
315
  '((((class color grayscale) (min-colors 88)) :inherit shadow))
316 317
  "`diff-mode' face used to highlight context and other side-information."
  :group 'diff-mode)
318 319 320
;; backward-compatibility alias
(put 'diff-context-face 'face-alias 'diff-context)
(defvar diff-context-face 'diff-context)
Stefan Monnier's avatar
Stefan Monnier committed
321

322 323
(defface diff-nonexistent
  '((t :inherit diff-file-header))
324 325
  "`diff-mode' face used to highlight nonexistent files in recursive diffs."
  :group 'diff-mode)
326 327 328
;; backward-compatibility alias
(put 'diff-nonexistent-face 'face-alias 'diff-nonexistent)
(defvar diff-nonexistent-face 'diff-nonexistent)
329

330 331
(defconst diff-yank-handler '(diff-yank-function))
(defun diff-yank-function (text)
332 333 334
  ;; FIXME: the yank-handler is now called separately on each piece of text
  ;; with a yank-handler property, so the next-single-property-change call
  ;; below will always return nil :-(   --stef
335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350
  (let ((mixed (next-single-property-change 0 'yank-handler text))
	(start (point)))
    ;; First insert the text.
    (insert text)
    ;; If the text does not include any diff markers and if we're not
    ;; yanking back into a diff-mode buffer, get rid of the prefixes.
    (unless (or mixed (derived-mode-p 'diff-mode))
      (undo-boundary)		; Just in case the user wanted the prefixes.
      (let ((re (save-excursion
		  (if (re-search-backward "^[><!][ \t]" start t)
		      (if (eq (char-after) ?!)
			  "^[!+- ][ \t]" "^[<>][ \t]")
		    "^[ <>!+-]"))))
	(save-excursion
	  (while (re-search-backward re start t)
	    (replace-match "" t t)))))))
351

352

353
(defvar diff-font-lock-keywords
354 355 356 357
  `(("^\\(@@ -[0-9,]+ \\+[0-9,]+ @@\\)\\(.*\\)$"          ;unified
     (1 diff-hunk-header-face) (2 diff-function-face))
    ("^\\(\\*\\{15\\}\\)\\(.*\\)$"                        ;context
     (1 diff-hunk-header-face) (2 diff-function-face))
358
    ("^\\*\\*\\* .+ \\*\\*\\*\\*". diff-hunk-header-face) ;context
359 360 361
    ("^--- .+ ----$"             . diff-hunk-header-face) ;context
    ("^[0-9,]+[acd][0-9,]+$"     . diff-hunk-header-face) ;normal
    ("^---$"                     . diff-hunk-header-face) ;normal
362 363 364 365 366
    ;; For file headers, accept files with spaces, but be careful to rule
    ;; out false-positives when matching hunk headers.
    ("^\\(---\\|\\+\\+\\+\\|\\*\\*\\*\\) \\([^\t\n]+?\\)\\(?:\t.*\\| \\(\\*\\*\\*\\*\\|----\\)\\)?\n"
     (0 diff-header-face)
     (2 (if (not (match-end 3)) diff-file-header-face) prepend))
367 368 369 370 371 372 373 374
    ("^\\([-<]\\)\\(.*\n\\)"
     (1 diff-indicator-removed-face) (2 diff-removed-face))
    ("^\\([+>]\\)\\(.*\n\\)"
     (1 diff-indicator-added-face) (2 diff-added-face))
    ("^\\(!\\)\\(.*\n\\)"
     (1 diff-indicator-changed-face) (2 diff-changed-face))
    ("^Index: \\(.+\\).*\n"
     (0 diff-header-face) (1 diff-index-face prepend))
375
    ("^Only in .*\n" . diff-nonexistent-face)
376
    ("^\\(#\\)\\(.*\\)"
377 378
     (1 font-lock-comment-delimiter-face)
     (2 font-lock-comment-face))
379
    ("^[^-=+*!<>#].*\n" (0 diff-context-face))))
380 381

(defconst diff-font-lock-defaults
382
  '(diff-font-lock-keywords t nil nil nil (font-lock-multiline . nil)))
383

384 385
(defvar diff-imenu-generic-expression
  ;; Prefer second name as first is most likely to be a backup or
386 387 388
  ;; version-control name.  The [\t\n] at the end of the unidiff pattern
  ;; catches Debian source diff files (which lack the trailing date).
  '((nil "\\+\\+\\+\\ \\([^\t\n]+\\)[\t\n]" 1) ; unidiffs
389 390
    (nil "^--- \\([^\t\n]+\\)\t.*\n\\*" 1))) ; context diffs

391
;;;;
392
;;;; Movement
393
;;;;
394

395
(defconst diff-hunk-header-re "^\\(@@ -[0-9,]+ \\+[0-9,]+ @@.*\\|\\*\\{15\\}.*\n\\*\\*\\* .+ \\*\\*\\*\\*\\|[0-9]+\\(,[0-9]+\\)?[acd][0-9]+\\(,[0-9]+\\)?\\)$")
396
(defconst diff-file-header-re (concat "^\\(--- .+\n\\+\\+\\+ \\|\\*\\*\\* .+\n--- \\|[^-+!<>0-9@* ]\\).+\n" (substring diff-hunk-header-re 1)))
397 398
(defvar diff-narrowed-to nil)

Stefan Monnier's avatar
Stefan Monnier committed
399
(defun diff-hunk-style (&optional style)
400
  (when (looking-at diff-hunk-header-re)
Stefan Monnier's avatar
Stefan Monnier committed
401
    (setq style (cdr (assq (char-after) '((?@ . unified) (?* . context)))))
402
    (goto-char (match-end 0)))
Stefan Monnier's avatar
Stefan Monnier committed
403 404 405 406 407
  style)

(defun diff-end-of-hunk (&optional style)
  ;; Especially important for unified (because headers are ambiguous).
  (setq style (diff-hunk-style style))
408
  (let ((end (and (re-search-forward (case style
409
				       ;; A `unified' header is ambiguous.
410
				       (unified (concat "^[^-+# \\]\\|"
411
							diff-file-header-re))
412 413 414 415 416 417 418
				       (context "^[^-+#! \\]")
				       (normal "^[^<>#\\]")
				       (t "^[^-+#!<> \\]"))
				     nil t)
		  (match-beginning 0))))
    ;; The return value is used by easy-mmode-define-navigation.
    (goto-char (or end (point-max)))))
419

420 421 422 423
(defun diff-beginning-of-hunk (&optional try-harder)
  "Move back to beginning of hunk.
If TRY-HARDER is non-nil, try to cater to the case where we're not in a hunk
but in the file header instead, in which case move forward to the first hunk."
424 425 426 427 428
  (beginning-of-line)
  (unless (looking-at diff-hunk-header-re)
    (forward-line 1)
    (condition-case ()
	(re-search-backward diff-hunk-header-re)
429 430 431 432 433
      (error
       (if (not try-harder)
           (error "Can't find the beginning of the hunk")
         (diff-beginning-of-file-and-junk)
         (diff-hunk-next))))))
434

435 436 437 438 439 440
(defun diff-unified-hunk-p ()
  (save-excursion
    (ignore-errors
      (diff-beginning-of-hunk)
      (looking-at "^@@"))))

441 442 443
(defun diff-beginning-of-file ()
  (beginning-of-line)
  (unless (looking-at diff-file-header-re)
444 445 446 447 448 449 450 451 452 453 454 455 456 457
    (let ((start (point))
          res)
      ;; diff-file-header-re may need to match up to 4 lines, so in case
      ;; we're inside the header, we need to move up to 3 lines forward.
      (forward-line 3)
      (if (and (setq res (re-search-backward diff-file-header-re nil t))
               ;; Maybe the 3 lines forward were too much and we matched
               ;; a file header after our starting point :-(
               (or (<= (point) start)
                   (setq res (re-search-backward diff-file-header-re nil t))))
          res
        (goto-char start)
        (error "Can't find the beginning of the file")))))
        
458 459

(defun diff-end-of-file ()
460
  (re-search-forward "^[-+#!<>0-9@* \\]" nil t)
461 462 463 464 465
  (re-search-forward (concat "^[^-+#!<>0-9@* \\]\\|" diff-file-header-re)
		     nil 'move)
  (if (match-beginning 1)
      (goto-char (match-beginning 1))
    (beginning-of-line)))
466

467 468
;; Define diff-{hunk,file}-{prev,next}
(easy-mmode-define-navigation
Stefan Monnier's avatar
Stefan Monnier committed
469 470 471 472
 diff-hunk diff-hunk-header-re "hunk" diff-end-of-hunk diff-restrict-view
 (if diff-auto-refine
     (condition-case-no-debug nil (diff-refine-hunk) (error nil))))

473 474
(easy-mmode-define-navigation
 diff-file diff-file-header-re "file" diff-end-of-hunk)
475 476 477 478 479 480

(defun diff-restrict-view (&optional arg)
  "Restrict the view to the current hunk.
If the prefix ARG is given, restrict the view to the current file instead."
  (interactive "P")
  (save-excursion
481
    (if arg (diff-beginning-of-file) (diff-beginning-of-hunk 'try-harder))
482 483 484 485 486 487
    (narrow-to-region (point)
		      (progn (if arg (diff-end-of-file) (diff-end-of-hunk))
			     (point)))
    (set (make-local-variable 'diff-narrowed-to) (if arg 'file 'hunk))))


488
(defun diff-hunk-kill ()
489 490 491
  "Kill current hunk."
  (interactive)
  (diff-beginning-of-hunk)
492
  (let* ((start (point))
493 494
	 (nexthunk (when (re-search-forward diff-hunk-header-re nil t)
		     (match-beginning 0)))
495 496 497
	 (firsthunk (ignore-errors
		      (goto-char start)
		      (diff-beginning-of-file) (diff-hunk-next) (point)))
498 499
	 (nextfile (ignore-errors (diff-file-next) (point)))
	 (inhibit-read-only t))
500
    (goto-char start)
501 502 503
    (if (and firsthunk (= firsthunk start)
	     (or (null nexthunk)
		 (and nextfile (> nexthunk nextfile))))
504
	;; It's the only hunk for this file, so kill the file.
505
	(diff-file-kill)
506 507 508
      (diff-end-of-hunk)
      (kill-region start (point)))))

509 510 511 512
(defun diff-beginning-of-file-and-junk ()
  "Go to the beginning of file-related diff-info.
This is like `diff-beginning-of-file' except it tries to skip back over leading
data such as \"Index: ...\" and such."
513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540
  (let* ((start (point))
         (prevfile (condition-case err
                       (save-excursion (diff-beginning-of-file) (point))
                     (error err)))
         (err (if (consp prevfile) prevfile))
         (nextfile (ignore-errors
                     (save-excursion
                       (goto-char start) (diff-file-next) (point))))
         ;; prevhunk is one of the limits.
         (prevhunk (save-excursion
                     (ignore-errors
                       (if (numberp prevfile) (goto-char prevfile))
                       (diff-hunk-prev) (point))))
         (previndex (save-excursion
                      (re-search-backward "^Index: " prevhunk t))))
    ;; If we're in the junk, we should use nextfile instead of prevfile.
    (if (and (numberp nextfile)
             (or (not (numberp prevfile))
                 (and previndex (> previndex prevfile))))
        (setq prevfile nextfile))
    (if (and previndex (numberp prevfile) (< previndex prevfile))
        (setq prevfile previndex))
    (if (and (numberp prevfile) (<= prevfile start))
        (goto-char prevfile)
      ;; File starts *after* the starting point: we really weren't in
      ;; a file diff but elsewhere.
      (goto-char start)
      (signal (car err) (cdr err)))))
541
          
542
(defun diff-file-kill ()
543 544
  "Kill current file's hunks."
  (interactive)
545
  (diff-beginning-of-file-and-junk)
546
  (let* ((start (point))
547
	 (inhibit-read-only t))
548
    (diff-end-of-file)
549
    (if (looking-at "^\n") (forward-char 1)) ;`tla' generates such diffs.
550 551
    (kill-region start (point))))

552 553 554 555 556 557 558 559 560 561 562 563 564 565 566
(defun diff-kill-junk ()
  "Kill spurious empty diffs."
  (interactive)
  (save-excursion
    (let ((inhibit-read-only t))
      (goto-char (point-min))
      (while (re-search-forward (concat "^\\(Index: .*\n\\)"
					"\\([^-+!* <>].*\n\\)*?"
					"\\(\\(Index:\\) \\|"
					diff-file-header-re "\\)")
				nil t)
	(delete-region (if (match-end 4) (match-beginning 0) (match-end 1))
		       (match-beginning 3))
	(beginning-of-line)))))

567 568 569 570 571 572 573
(defun diff-count-matches (re start end)
  (save-excursion
    (let ((n 0))
      (goto-char start)
      (while (re-search-forward re end t) (incf n))
      n)))

574 575 576 577 578 579 580
(defun diff-splittable-p ()
  (save-excursion
    (beginning-of-line)
    (and (looking-at "^[-+ ]")
         (progn (forward-line -1) (looking-at "^[-+ ]"))
         (diff-unified-hunk-p))))

581 582 583 584 585 586 587 588 589 590 591 592
(defun diff-split-hunk ()
  "Split the current (unified diff) hunk at point into two hunks."
  (interactive)
  (beginning-of-line)
  (let ((pos (point))
	(start (progn (diff-beginning-of-hunk) (point))))
    (unless (looking-at "@@ -\\([0-9]+\\),[0-9]+ \\+\\([0-9]+\\),[0-9]+ @@")
      (error "diff-split-hunk only works on unified context diffs"))
    (forward-line 1)
    (let* ((start1 (string-to-number (match-string 1)))
	   (start2 (string-to-number (match-string 2)))
	   (newstart1 (+ start1 (diff-count-matches "^[- \t]" (point) pos)))
593 594
	   (newstart2 (+ start2 (diff-count-matches "^[+ \t]" (point) pos)))
	   (inhibit-read-only t))
595 596 597 598 599 600
      (goto-char pos)
      ;; Hopefully the after-change-function will not screw us over.
      (insert "@@ -" (number-to-string newstart1) ",1 +"
	      (number-to-string newstart2) ",1 @@\n")
      ;; Fix the original hunk-header.
      (diff-fixup-modifs start pos))))
601

602

603 604 605 606
;;;;
;;;; jump to other buffers
;;;;

607 608
(defvar diff-remembered-files-alist nil)

609 610 611
(defun diff-filename-drop-dir (file)
  (when (string-match "/" file) (substring file (match-end 0))))

612 613 614
(defun diff-merge-strings (ancestor from to)
  "Merge the diff between ANCESTOR and FROM into TO.
Returns the merged string if successful or nil otherwise.
615
The strings are assumed not to contain any \"\\n\" (i.e. end of line).
616 617 618 619 620 621 622 623
If ANCESTOR = FROM, returns TO.
If ANCESTOR = TO, returns FROM.
The heuristic is simplistic and only really works for cases
like \(diff-merge-strings \"b/foo\" \"b/bar\" \"/a/c/foo\")."
  ;; Ideally, we want:
  ;;   AMB ANB CMD -> CND
  ;; but that's ambiguous if `foo' or `bar' is empty:
  ;; a/foo a/foo1 b/foo.c -> b/foo1.c but not 1b/foo.c or b/foo.c1
624
  (let ((str (concat ancestor "\n" from "\n" to)))
625
    (when (and (string-match (concat
626 627
			      "\\`\\(.*?\\)\\(.*\\)\\(.*\\)\n"
			      "\\1\\(.*\\)\\3\n"
628 629 630 631 632 633
			      "\\(.*\\(\\2\\).*\\)\\'") str)
	       (equal to (match-string 5 str)))
      (concat (substring str (match-beginning 5) (match-beginning 6))
	      (match-string 4 str)
	      (substring str (match-end 6) (match-end 5))))))

634 635 636 637 638 639 640 641 642 643 644 645
(defun diff-tell-file-name (old name)
  "Tell Emacs where the find the source file of the current hunk.
If the OLD prefix arg is passed, tell the file NAME of the old file."
  (interactive
   (let* ((old current-prefix-arg)
	  (fs (diff-hunk-file-names current-prefix-arg)))
     (unless fs (error "No file name to look for"))
     (list old (read-file-name (format "File for %s: " (car fs))
			       nil (diff-find-file-name old) t))))
  (let ((fs (diff-hunk-file-names old)))
    (unless fs (error "No file name to look for"))
    (push (cons fs name) diff-remembered-files-alist)))
646

647 648
(defun diff-hunk-file-names (&optional old)
  "Give the list of file names textually mentioned for the current hunk."
649 650 651 652
  (save-excursion
    (unless (looking-at diff-file-header-re)
      (or (ignore-errors (diff-beginning-of-file))
	  (re-search-forward diff-file-header-re nil t)))
653
    (let ((limit (save-excursion
654
		   (condition-case ()
655
		       (progn (diff-hunk-prev) (point))
656
		     (error (point-min)))))
657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674
	  (header-files
	   (if (looking-at "[-*][-*][-*] \\(\\S-+\\)\\(\\s-.*\\)?\n[-+][-+][-+] \\(\\S-+\\)")
	       (list (if old (match-string 1) (match-string 3))
		     (if old (match-string 3) (match-string 1)))
	     (forward-line 1) nil)))
      (delq nil
	    (append
	     (when (and (not old)
			(save-excursion
			  (re-search-backward "^Index: \\(.+\\)" limit t)))
	       (list (match-string 1)))
	     header-files
	     (when (re-search-backward
		    "^diff \\(-\\S-+ +\\)*\\(\\S-+\\)\\( +\\(\\S-+\\)\\)?"
		    nil t)
	       (list (if old (match-string 2) (match-string 4))
		     (if old (match-string 4) (match-string 2)))))))))

675
(defun diff-find-file-name (&optional old batch prefix)
676
  "Return the file corresponding to the current patch.
677
Non-nil OLD means that we want the old file.
678 679
Non-nil BATCH means to prefer returning an incorrect answer than to prompt
the user.
680
PREFIX is only used internally: don't use it."
681 682 683 684 685
  (save-excursion
    (unless (looking-at diff-file-header-re)
      (or (ignore-errors (diff-beginning-of-file))
	  (re-search-forward diff-file-header-re nil t)))
    (let ((fs (diff-hunk-file-names old)))
686
      (if prefix (setq fs (mapcar (lambda (f) (concat prefix f)) fs)))
687
      (or
688 689 690 691 692 693 694 695 696 697 698 699 700
       ;; use any previously used preference
       (cdr (assoc fs diff-remembered-files-alist))
       ;; try to be clever and use previous choices as an inspiration
       (dolist (rf diff-remembered-files-alist)
	 (let ((newfile (diff-merge-strings (caar rf) (car fs) (cdr rf))))
	   (if (and newfile (file-exists-p newfile)) (return newfile))))
       ;; look for each file in turn.  If none found, try again but
       ;; ignoring the first level of directory, ...
       (do* ((files fs (delq nil (mapcar 'diff-filename-drop-dir files)))
	     (file nil nil))
	   ((or (null files)
		(setq file (do* ((files files (cdr files))
				 (file (car files) (car files)))
701 702 703
			       ;; Use file-regular-p to avoid
			       ;; /dev/null, directories, etc.
			       ((or (null file) (file-regular-p file))
704 705 706
				file))))
	    file))
       ;; <foo>.rej patches implicitly apply to <foo>
707 708 709
       (and (string-match "\\.rej\\'" (or buffer-file-name ""))
	    (let ((file (substring buffer-file-name 0 (match-beginning 0))))
	      (when (file-exists-p file) file)))
710 711 712 713 714 715
       ;; If we haven't found the file, maybe it's because we haven't paid
       ;; attention to the PCL-CVS hint.
       (and (not prefix)
	    (boundp 'cvs-pcl-cvs-dirchange-re)
	    (save-excursion
	      (re-search-backward cvs-pcl-cvs-dirchange-re nil t))
716 717 718 719
	    (diff-find-file-name old batch (match-string 1)))
       ;; Invent something, if necessary.
       (when batch
         (or (car fs) default-directory))
720 721 722 723 724
       ;; if all else fails, ask the user
       (let ((file (read-file-name (format "Use file %s: " (or (first fs) ""))
				   nil (first fs) t (first fs))))
	 (set (make-local-variable 'diff-remembered-files-alist)
	      (cons (cons fs file) diff-remembered-files-alist))
725 726
	 file)))))

727

728 729 730 731
(defun diff-ediff-patch ()
  "Call `ediff-patch-file' on the current buffer."
  (interactive)
  (condition-case err
732
      (ediff-patch-file nil (current-buffer))
733 734
    (wrong-number-of-arguments (ediff-patch-file))))

735
;;;;
736
;;;; Conversion functions
737
;;;;
738 739 740 741 742 743 744

;;(defvar diff-inhibit-after-change nil
;;  "Non-nil means inhibit `diff-mode's after-change functions.")

(defun diff-unified->context (start end)
  "Convert unified diffs to context diffs.
START and END are either taken from the region (if a prefix arg is given) or
745
else cover the whole buffer."
746 747
  (interactive (if (or current-prefix-arg (and transient-mark-mode mark-active))
		   (list (region-beginning) (region-end))
748
		 (list (point-min) (point-max))))
749
  (unless (markerp end) (setq end (copy-marker end t)))
750 751 752 753
  (let (;;(diff-inhibit-after-change t)
	(inhibit-read-only t))
    (save-excursion
      (goto-char start)
754
      (while (and (re-search-forward "^\\(\\(---\\) .+\n\\(\\+\\+\\+\\) .+\\|@@ -\\([0-9]+\\),\\([0-9]+\\) \\+\\([0-9]+\\),\\([0-9]+\\) @@.*\\)$" nil t)
755 756 757
		  (< (point) end))
	(combine-after-change-calls
	  (if (match-beginning 2)
758
	      ;; we matched a file header
759 760 761 762 763 764 765 766
	      (progn
		;; use reverse order to make sure the indices are kept valid
		(replace-match "---" t t nil 3)
		(replace-match "***" t t nil 2))
	    ;; we matched a hunk header
	    (let ((line1 (match-string 4))
		  (lines1 (match-string 5))
		  (line2 (match-string 6))
767 768 769 770 771 772
		  (lines2 (match-string 7))
		  ;; Variables to use the special undo function.
		  (old-undo buffer-undo-list)
		  (old-end (marker-position end))
		  (start (match-beginning 0))
		  (reversible t))
773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790
	      (replace-match
	       (concat "***************\n*** " line1 ","
		       (number-to-string (+ (string-to-number line1)
					    (string-to-number lines1)
					    -1)) " ****"))
	      (forward-line 1)
	      (save-restriction
		(narrow-to-region (point)
				  (progn (diff-end-of-hunk 'unified) (point)))
		(let ((hunk (buffer-string)))
		  (goto-char (point-min))
		  (if (not (save-excursion (re-search-forward "^-" nil t)))
		      (delete-region (point) (point-max))
		    (goto-char (point-max))
		    (let ((modif nil) last-pt)
		      (while (progn (setq last-pt (point))
				    (= (forward-line -1) 0))
			(case (char-after)
Juanma Barranquero's avatar
Juanma Barranquero committed
791
			  (?\s (insert " ") (setq modif nil) (backward-char 1))
792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813
			  (?+ (delete-region (point) last-pt) (setq modif t))
			  (?- (if (not modif)
				  (progn (forward-char 1)
					 (insert " "))
				(delete-char 1)
				(insert "! "))
			      (backward-char 2))
			  (?\\ (when (save-excursion (forward-line -1)
						     (= (char-after) ?+))
				 (delete-region (point) last-pt) (setq modif t)))
			  (t (setq modif nil))))))
		  (goto-char (point-max))
		  (save-excursion
		    (insert "--- " line2 ","
			    (number-to-string (+ (string-to-number line2)
						 (string-to-number lines2)
						 -1)) " ----\n" hunk))
		  ;;(goto-char (point-min))
		  (forward-line 1)
		  (if (not (save-excursion (re-search-forward "^+" nil t)))
		      (delete-region (point) (point-max))
		    (let ((modif nil) (delete nil))
814 815 816 817 818 819 820 821
		      (if (save-excursion (re-search-forward "^\\+.*\n-" nil t))
                          ;; Normally, lines in a substitution come with
                          ;; first the removals and then the additions, and
                          ;; the context->unified function follows this
                          ;; convention, of course.  Yet, other alternatives
                          ;; are valid as well, but they preclude the use of
                          ;; context->unified as an undo command.
			  (setq reversible nil))
822 823
		      (while (not (eobp))
			(case (char-after)
Juanma Barranquero's avatar
Juanma Barranquero committed
824
			  (?\s (insert " ") (setq modif nil) (backward-char 1))
825 826 827 828 829 830 831 832 833 834 835 836 837 838 839
			  (?- (setq delete t) (setq modif t))
			  (?+ (if (not modif)
				  (progn (forward-char 1)
					 (insert " "))
				(delete-char 1)
				(insert "! "))
			      (backward-char 2))
			  (?\\ (when (save-excursion (forward-line 1)
						     (not (eobp)))
				 (setq delete t) (setq modif t)))
			  (t (setq modif nil)))
			(let ((last-pt (point)))
			  (forward-line 1)
			  (when delete
			    (delete-region last-pt (point))
840 841 842 843 844 845 846 847 848
			    (setq delete nil)))))))
		(unless (or (not reversible) (eq buffer-undo-list t))
                  ;; Drop the many undo entries and replace them with
                  ;; a single entry that uses diff-context->unified to do
                  ;; the work.
		  (setq buffer-undo-list
			(cons (list 'apply (- old-end end) start (point-max)
				    'diff-context->unified start (point-max))
			      old-undo)))))))))))
849

850
(defun diff-context->unified (start end &optional to-context)
851
  "Convert context diffs to unified diffs.
852 853 854 855
START and END are either taken from the region
\(when it is highlighted) or else cover the whole buffer.
With a prefix argument, convert unified format to context format."
  (interactive (if (and transient-mark-mode mark-active)
856
		   (list (region-beginning) (region-end) current-prefix-arg)
857 858 859
		 (list (point-min) (point-max) current-prefix-arg)))
  (if to-context
      (diff-unified->context start end)
860
    (unless (markerp end) (setq end (copy-marker end t)))
861
    (let ( ;;(diff-inhibit-after-change t)
Stefan Monnier's avatar
Stefan Monnier committed
862
          (inhibit-read-only t))
863
      (save-excursion
Stefan Monnier's avatar
Stefan Monnier committed
864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944
        (goto-char start)
        (while (and (re-search-forward "^\\(\\(\\*\\*\\*\\) .+\n\\(---\\) .+\\|\\*\\{15\\}.*\n\\*\\*\\* \\([0-9]+\\),\\(-?[0-9]+\\) \\*\\*\\*\\*\\)$" nil t)
                    (< (point) end))
          (combine-after-change-calls
            (if (match-beginning 2)
                ;; we matched a file header
                (progn
                  ;; use reverse order to make sure the indices are kept valid
                  (replace-match "+++" t t nil 3)
                  (replace-match "---" t t nil 2))
              ;; we matched a hunk header
              (let ((line1s (match-string 4))
                    (line1e (match-string 5))
                    (pt1 (match-beginning 0))
                    ;; Variables to use the special undo function.
                    (old-undo buffer-undo-list)
                    (old-end (marker-position end))
                    (reversible t))
                (replace-match "")
                (unless (re-search-forward
                         "^--- \\([0-9]+\\),\\(-?[0-9]+\\) ----$" nil t)
                  (error "Can't find matching `--- n1,n2 ----' line"))
                (let ((line2s (match-string 1))
                      (line2e (match-string 2))
                      (pt2 (progn
                             (delete-region (progn (beginning-of-line) (point))
                                            (progn (forward-line 1) (point)))
                             (point-marker))))
                  (goto-char pt1)
                  (forward-line 1)
                  (while (< (point) pt2)
                    (case (char-after)
                      (?! (delete-char 2) (insert "-") (forward-line 1))
                      (?- (forward-char 1) (delete-char 1) (forward-line 1))
                      (?\s           ;merge with the other half of the chunk
                       (let* ((endline2
                               (save-excursion
                                 (goto-char pt2) (forward-line 1) (point))))
                         (case (char-after pt2)
                           ((?! ?+)
                            (insert "+"
                                    (prog1 (buffer-substring (+ pt2 2) endline2)
                                      (delete-region pt2 endline2))))
                           (?\s
                            (unless (= (- endline2 pt2)
                                       (- (line-beginning-position 2) (point)))
                              ;; If the two lines we're merging don't have the
                              ;; same length (can happen with "diff -b"), then
                              ;; diff-unified->context will not properly undo
                              ;; this operation.
                              (setq reversible nil))
                            (delete-region pt2 endline2)
                            (delete-char 1)
                            (forward-line 1))
                           (?\\ (forward-line 1))
                           (t (setq reversible nil)
                              (delete-char 1) (forward-line 1)))))
                      (t (setq reversible nil) (forward-line 1))))
                  (while (looking-at "[+! ] ")
                    (if (/= (char-after) ?!) (forward-char 1)
                      (delete-char 1) (insert "+"))
                    (delete-char 1) (forward-line 1))
                  (save-excursion
                    (goto-char pt1)
                    (insert "@@ -" line1s ","
                            (number-to-string (- (string-to-number line1e)
                                                 (string-to-number line1s)
                                                 -1))
                            " +" line2s ","
                            (number-to-string (- (string-to-number line2e)
                                                 (string-to-number line2s)
                                                 -1)) " @@"))
                  (set-marker pt2 nil)
                  ;; The whole procedure succeeded, let's replace the myriad
                  ;; of undo elements with just a single special one.
                  (unless (or (not reversible) (eq buffer-undo-list t))
                    (setq buffer-undo-list
                          (cons (list 'apply (- old-end end) pt1 (point)
                                      'diff-unified->context pt1 (point))
                                old-undo)))
                  )))))))))
945 946 947 948

(defun diff-reverse-direction (start end)
  "Reverse the direction of the diffs.
START and END are either taken from the region (if a prefix arg is given) or
949
else cover the whole buffer."
950 951
  (interactive (if (or current-prefix-arg (and transient-mark-mode mark-active))
		   (list (region-beginning) (region-end))
952
		 (list (point-min) (point-max))))
953
  (unless (markerp end) (setq end (copy-marker end t)))
954 955 956 957
  (let (;;(diff-inhibit-after-change t)
	(inhibit-read-only t))
    (save-excursion
      (goto-char start)
958
      (while (and (re-search-forward "^\\(\\([-*][-*][-*] \\)\\(.+\\)\n\\([-+][-+][-+] \\)\\(.+\\)\\|\\*\\{15\\}.*\n\\*\\*\\* \\(.+\\) \\*\\*\\*\\*\\|@@ -\\([0-9,]+\\) \\+\\([0-9,]+\\) @@.*\\)$" nil t)
959 960 961 962 963 964 965 966 967 968 969 970
		  (< (point) end))
	(combine-after-change-calls
	  (cond
	   ;; a file header
	   ((match-beginning 2) (replace-match "\\2\\5\n\\4\\3" nil))
	   ;; a context-diff hunk header
	   ((match-beginning 6)
	    (let ((pt-lines1 (match-beginning 6))
		  (lines1 (match-string 6)))
	      (replace-match "" nil nil nil 6)
	      (forward-line 1)
	      (let ((half1s (point)))
971
		(while (looking-at "[-! \\][ \t]\\|#")
972 973
		  (when (= (char-after) ?-) (delete-char 1) (insert "+"))
		  (forward-line 1))
974
		(let ((half1 (delete-and-extract-region half1s (point))))
975 976 977 978 979 980 981
		  (unless (looking-at "^--- \\([0-9]+,-?[0-9]+\\) ----$")
		    (insert half1)
		    (error "Can't find matching `--- n1,n2 ----' line"))
		  (let ((str1 (match-string 1)))
		    (replace-match lines1 nil nil nil 1)
		    (forward-line 1)
		    (let ((half2s (point)))
982
		      (while (looking-at "[!+ \\][ \t]\\|#")
983 984
			(when (= (char-after) ?+) (delete-char 1) (insert "-"))
			(forward-line 1))
Stefan Monnier's avatar