diff-mode.el 78.3 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,
Stefan Monnier's avatar
Stefan Monnier committed
4
;;   2005, 2006, 2007, 2008, 2009 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

;; This file is part of GNU Emacs.

11
;; GNU Emacs is free software: you can redistribute it and/or modify
12
;; it under the terms of the GNU General Public License as published by
13 14
;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.
15 16 17 18 19 20 21

;; 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
22
;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
23 24 25

;;; Commentary:

26
;; Provides support for font-lock, outline, navigation
27 28 29
;; commands, editing and various conversions as well as jumping
;; to the corresponding source file.

30
;; Inspired by Pavel Machek's patch-mode.el (<pavel@@atrey.karlin.mff.cuni.cz>)
Pavel Janík's avatar
Pavel Janík committed
31
;; Some efforts were spent to have it somewhat compatible with XEmacs'
32 33 34 35
;; diff-mode as well as with compilation-minor-mode

;; Bugs:

36
;; - Reverse doesn't work with normal diffs.
37 38 39

;; Todo:

40 41
;; - Improve `diff-add-change-log-entries-other-window',
;;   it is very simplistic now.
Lute Kamstra's avatar
Lute Kamstra committed
42
;;
43 44 45 46 47 48 49
;; - 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".
50
;;   Maybe just use `wiggle' (by Neil Brown) to do it for us.
51
;;
52 53
;; - in diff-apply-hunk, strip context in replace-match to better
;;   preserve markers and spacing.
54
;; - Handle `diff -b' output in context->unified.
55 56 57 58

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

59 60
(defvar add-log-buffer-file-name-function)

61 62

(defgroup diff-mode ()
63
  "Major mode for viewing/editing diffs."
64
  :version "21.1"
65 66 67
  :group 'tools
  :group 'diff)

68
(defcustom diff-default-read-only nil
69 70 71 72
  "If non-nil, `diff-mode' buffers default to being read-only."
  :type 'boolean
  :group 'diff-mode)

73
(defcustom diff-jump-to-old-file nil
74
  "Non-nil means `diff-goto-source' jumps to the old file.
75
Else, it jumps to the new file."
76 77
  :type 'boolean
  :group 'diff-mode)
78

79
(defcustom diff-update-on-the-fly t
Lute Kamstra's avatar
Lute Kamstra committed
80
  "Non-nil means hunk headers are kept up-to-date on-the-fly.
81 82 83 84 85
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)."
86 87
  :type 'boolean
  :group 'diff-mode)
88

89
(defcustom diff-advance-after-apply-hunk t
Lute Kamstra's avatar
Lute Kamstra committed
90
  "Non-nil means `diff-apply-hunk' will move to the next hunk after applying."
91 92
  :type 'boolean
  :group 'diff-mode)
93

94 95 96
(defcustom diff-mode-hook nil
  "Run after setting up the `diff-mode' major mode."
  :type 'hook
97 98
  :options '(diff-delete-empty-files diff-make-unified)
  :group 'diff-mode)
99 100 101 102

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

103
;;;;
104
;;;; keymap, menu, ...
105
;;;;
106

107
(easy-mmode-defmap diff-mode-shared-map
108
  '(;; From Pavel Machek's patch-mode.
109 110 111 112
    ("n" . diff-hunk-next)
    ("N" . diff-file-next)
    ("p" . diff-hunk-prev)
    ("P" . diff-file-prev)
113 114
    ("\t" . diff-hunk-next)
    ([backtab] . diff-hunk-prev)
115 116
    ("k" . diff-hunk-kill)
    ("K" . diff-file-kill)
117
    ;; From compilation-minor-mode.
118 119
    ("}" . diff-file-next)
    ("{" . diff-file-prev)
120
    ("\C-m" . diff-goto-source)
121
    ([mouse-2] . diff-goto-source)
122
    ;; From XEmacs' diff-mode.
123 124
    ;; Standard M-w is useful, so don't change M-W.
    ;;("W" . widen)
125 126 127 128 129 130 131 132
    ;;("." . 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)
133 134 135 136 137 138 139 140
    ;; 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
141
    ("q" . quit-window))
142
  "Basic keymap for `diff-mode', bound to various prefix keys.")
143

144
(easy-mmode-defmap diff-mode-map
145
  `(("\e" . ,diff-mode-shared-map)
146 147
    ;; From compilation-minor-mode.
    ("\C-c\C-c" . diff-goto-source)
148 149
    ;; By analogy with the global C-x 4 a binding.
    ("\C-x4A" . diff-add-change-log-entries-other-window)
150
    ;; Misc operations.
151
    ("\C-c\C-a" . diff-apply-hunk)
152 153 154
    ("\C-c\C-e" . diff-ediff-patch)
    ("\C-c\C-n" . diff-restrict-view)
    ("\C-c\C-s" . diff-split-hunk)
155
    ("\C-c\C-t" . diff-test-hunk)
Stefan Monnier's avatar
Stefan Monnier committed
156
    ("\C-c\C-r" . diff-reverse-direction)
157
    ("\C-c\C-u" . diff-context->unified)
158 159
    ;; `d' because it duplicates the context :-(  --Stef
    ("\C-c\C-d" . diff-unified->context)
Stefan Monnier's avatar
Stefan Monnier committed
160 161
    ("\C-c\C-w" . diff-ignore-whitespace-hunk)
    ("\C-c\C-b" . diff-refine-hunk)  ;No reason for `b' :-(
162
    ("\C-c\C-f" . next-error-follow-minor-mode))
163 164 165 166 167
  "Keymap for `diff-mode'.  See also `diff-mode-shared-map'.")

(easy-menu-define diff-mode-menu diff-mode-map
  "Menu for `diff-mode'."
  '("Diff"
Dan Nicolaescu's avatar
Dan Nicolaescu committed
168 169 170 171 172 173 174 175
    ["Jump to Source"		diff-goto-source
     :help "Jump to the corresponding source line"]
    ["Apply hunk"		diff-apply-hunk
     :help "Apply the current hunk to the source file and go to the next"]
    ["Test applying hunk"	diff-test-hunk
     :help "See whether it's possible to apply the current hunk"]
    ["Apply diff with Ediff"	diff-ediff-patch
     :help "Call `ediff-patch-file' on the current buffer"]
176
    ["Create Change Log entries" diff-add-change-log-entries-other-window
Dan Nicolaescu's avatar
Dan Nicolaescu committed
177
     :help "Create ChangeLog entries for the changes in the diff buffer"]
Stefan Monnier's avatar
Stefan Monnier committed
178
    "-----"
Dan Nicolaescu's avatar
Dan Nicolaescu committed
179 180 181 182 183 184
    ["Reverse direction"	diff-reverse-direction
     :help "Reverse the direction of the diffs"]
    ["Context -> Unified"	diff-context->unified
     :help "Convert context diffs to unified diffs"]
    ["Unified -> Context"	diff-unified->context
     :help "Convert unified diffs to context diffs"]
185
    ;;["Fixup Headers"		diff-fixup-modifs	(not buffer-read-only)]
186
    ["Show trailing whitespace" whitespace-mode
187
     :style toggle :selected (and (boundp 'whitespace-mode) whitespace-mode)
188
     :help "Show trailing whitespace in modified lines"]
Stefan Monnier's avatar
Stefan Monnier committed
189
    "-----"
Dan Nicolaescu's avatar
Dan Nicolaescu committed
190 191 192 193 194 195 196 197 198 199 200
    ["Split hunk"		diff-split-hunk
     :active (diff-splittable-p)
     :help "Split the current (unified diff) hunk at point into two hunks"]
    ["Ignore whitespace changes" diff-ignore-whitespace-hunk
     :help "Re-diff the current hunk, ignoring whitespace differences"]
    ["Highlight fine changes"	diff-refine-hunk
     :help "Highlight changes of hunk at point at a finer granularity"]
    ["Kill current hunk"	diff-hunk-kill
     :help "Kill current hunk"]
    ["Kill current file's hunks" diff-file-kill
     :help "Kill all current file's hunks"]
Stefan Monnier's avatar
Stefan Monnier committed
201
    "-----"
Dan Nicolaescu's avatar
Dan Nicolaescu committed
202 203 204 205 206 207 208 209
    ["Previous Hunk"		diff-hunk-prev
     :help "Go to the previous count'th hunk"]
    ["Next Hunk"		diff-hunk-next
     :help "Go to the next count'th hunk"]
    ["Previous File"		diff-file-prev
     :help "Go to the previous count'th file"]
    ["Next File"		diff-file-next
     :help "Go to the next count'th file"]
210 211
    ))

212
(defcustom diff-minor-mode-prefix "\C-c="
213
  "Prefix key for `diff-minor-mode' commands."
214 215
  :type '(choice (string "\e") (string "C-c=") string)
  :group 'diff-mode)
216

217 218
(easy-mmode-defmap diff-minor-mode-map
  `((,diff-minor-mode-prefix . ,diff-mode-shared-map))
219 220
  "Keymap for `diff-minor-mode'.  See also `diff-mode-shared-map'.")

221 222 223 224
(define-minor-mode diff-auto-refine-mode
  "Automatically highlight changes in detail as the user visits hunks.
When transitioning from disabled to enabled,
try to refine the current hunk, as well."
225
  :group 'diff-mode :init-value t :lighter nil ;; " Auto-Refine"
226 227
  (when diff-auto-refine-mode
    (condition-case-no-debug nil (diff-refine-hunk) (error nil))))
228

229
;;;;
230
;;;; font-lock support
231
;;;;
232

233
(defface diff-header
234
  '((((class color) (min-colors 88) (background light))
235
     :background "grey80")
236
    (((class color) (min-colors 88) (background dark))
237
     :background "grey45")
238
    (((class color) (background light))
239
     :foreground "blue1" :weight bold)
240
    (((class color) (background dark))
241 242
     :foreground "green" :weight bold)
    (t :weight bold))
243 244
  "`diff-mode' face inherited by hunk and index header faces."
  :group 'diff-mode)
245 246 247
;; backward-compatibility alias
(put 'diff-header-face 'face-alias 'diff-header)
(defvar diff-header-face 'diff-header)
Stefan Monnier's avatar
Stefan Monnier committed
248

249
(defface diff-file-header
250
  '((((class color) (min-colors 88) (background light))
251
     :background "grey70" :weight bold)
252
    (((class color) (min-colors 88) (background dark))
253
     :background "grey60" :weight bold)
254
    (((class color) (background light))
255
     :foreground "green" :weight bold)
256
    (((class color) (background dark))
257 258
     :foreground "cyan" :weight bold)
    (t :weight bold))			; :height 1.3
259 260
  "`diff-mode' face used to highlight file header lines."
  :group 'diff-mode)
261 262 263
;; backward-compatibility alias
(put 'diff-file-header-face 'face-alias 'diff-file-header)
(defvar diff-file-header-face 'diff-file-header)
264

265 266
(defface diff-index
  '((t :inherit diff-file-header))
267 268
  "`diff-mode' face used to highlight index header lines."
  :group 'diff-mode)
269 270 271
;; backward-compatibility alias
(put 'diff-index-face 'face-alias 'diff-index)
(defvar diff-index-face 'diff-index)
272

273 274
(defface diff-hunk-header
  '((t :inherit diff-header))
275 276
  "`diff-mode' face used to highlight hunk header lines."
  :group 'diff-mode)
277 278 279
;; backward-compatibility alias
(put 'diff-hunk-header-face 'face-alias 'diff-hunk-header)
(defvar diff-hunk-header-face 'diff-hunk-header)
280

281 282
(defface diff-removed
  '((t :inherit diff-changed))
283 284
  "`diff-mode' face used to highlight removed lines."
  :group 'diff-mode)
285 286 287
;; backward-compatibility alias
(put 'diff-removed-face 'face-alias 'diff-removed)
(defvar diff-removed-face 'diff-removed)
288

289 290
(defface diff-added
  '((t :inherit diff-changed))
291 292
  "`diff-mode' face used to highlight added lines."
  :group 'diff-mode)
293 294 295
;; backward-compatibility alias
(put 'diff-added-face 'face-alias 'diff-added)
(defvar diff-added-face 'diff-added)
296

297
(defface diff-changed
298
  '((((type tty pc) (class color) (background light))
299
     :foreground "magenta" :weight bold :slant italic)
300
    (((type tty pc) (class color) (background dark))
301
     :foreground "yellow" :weight bold :slant italic))
302 303
  "`diff-mode' face used to highlight changed lines."
  :group 'diff-mode)
304 305 306
;; backward-compatibility alias
(put 'diff-changed-face 'face-alias 'diff-changed)
(defvar diff-changed-face 'diff-changed)
307

308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328
(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)

329
(defface diff-function
330
  '((t :inherit diff-header))
331 332
  "`diff-mode' face used to highlight function names produced by \"diff -p\"."
  :group 'diff-mode)
333 334 335
;; backward-compatibility alias
(put 'diff-function-face 'face-alias 'diff-function)
(defvar diff-function-face 'diff-function)
336

337
(defface diff-context
338
  '((((class color grayscale) (min-colors 88)) :inherit shadow))
339 340
  "`diff-mode' face used to highlight context and other side-information."
  :group 'diff-mode)
341 342 343
;; backward-compatibility alias
(put 'diff-context-face 'face-alias 'diff-context)
(defvar diff-context-face 'diff-context)
Stefan Monnier's avatar
Stefan Monnier committed
344

345 346
(defface diff-nonexistent
  '((t :inherit diff-file-header))
347 348
  "`diff-mode' face used to highlight nonexistent files in recursive diffs."
  :group 'diff-mode)
349 350 351
;; backward-compatibility alias
(put 'diff-nonexistent-face 'face-alias 'diff-nonexistent)
(defvar diff-nonexistent-face 'diff-nonexistent)
352

353 354
(defconst diff-yank-handler '(diff-yank-function))
(defun diff-yank-function (text)
355 356 357
  ;; 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
358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373
  (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)))))))
374

375
(defconst diff-hunk-header-re-unified
376
  "^@@ -\\([0-9]+\\)\\(?:,\\([0-9]+\\)\\)? \\+\\([0-9]+\\)\\(?:,\\([0-9]+\\)\\)? @@")
377 378
(defconst diff-context-mid-hunk-header-re
  "--- \\([0-9]+\\)\\(?:,\\([0-9]+\\)\\)? ----$")
379

380
(defvar diff-font-lock-keywords
381 382
  `((,(concat "\\(" diff-hunk-header-re-unified "\\)\\(.*\\)$")
     (1 diff-hunk-header-face) (6 diff-function-face))
383 384
    ("^\\(\\*\\{15\\}\\)\\(.*\\)$"                        ;context
     (1 diff-hunk-header-face) (2 diff-function-face))
385
    ("^\\*\\*\\* .+ \\*\\*\\*\\*". diff-hunk-header-face) ;context
386
    (,diff-context-mid-hunk-header-re . diff-hunk-header-face) ;context
387 388
    ("^[0-9,]+[acd][0-9,]+$"     . diff-hunk-header-face) ;normal
    ("^---$"                     . diff-hunk-header-face) ;normal
389 390 391 392 393
    ;; 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))
394 395 396 397 398 399 400 401
    ("^\\([-<]\\)\\(.*\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))
402
    ("^Only in .*\n" . diff-nonexistent-face)
403
    ("^\\(#\\)\\(.*\\)"
404 405
     (1 font-lock-comment-delimiter-face)
     (2 font-lock-comment-face))
406
    ("^[^-=+*!<>#].*\n" (0 diff-context-face))))
407 408

(defconst diff-font-lock-defaults
409
  '(diff-font-lock-keywords t nil nil nil (font-lock-multiline . nil)))
410

411 412
(defvar diff-imenu-generic-expression
  ;; Prefer second name as first is most likely to be a backup or
413 414 415
  ;; 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
416 417
    (nil "^--- \\([^\t\n]+\\)\t.*\n\\*" 1))) ; context diffs

418
;;;;
419
;;;; Movement
420
;;;;
421

422 423 424 425 426 427 428 429
(defvar diff-valid-unified-empty-line t
  "If non-nil, empty lines are valid in unified diffs.
Some versions of diff replace all-blank context lines in unified format with
empty lines.  This makes the format less robust, but is tolerated.
See http://lists.gnu.org/archive/html/emacs-devel/2007-11/msg01990.html")

(defconst diff-hunk-header-re
  (concat "^\\(?:" diff-hunk-header-re-unified ".*\\|\\*\\{15\\}.*\n\\*\\*\\* .+ \\*\\*\\*\\*\\|[0-9]+\\(,[0-9]+\\)?[acd][0-9]+\\(,[0-9]+\\)?\\)$"))
430
(defconst diff-file-header-re (concat "^\\(--- .+\n\\+\\+\\+ \\|\\*\\*\\* .+\n--- \\|[^-+!<>0-9@* \n]\\).+\n" (substring diff-hunk-header-re 1)))
431 432
(defvar diff-narrowed-to nil)

Stefan Monnier's avatar
Stefan Monnier committed
433
(defun diff-hunk-style (&optional style)
434
  (when (looking-at diff-hunk-header-re)
Stefan Monnier's avatar
Stefan Monnier committed
435
    (setq style (cdr (assq (char-after) '((?@ . unified) (?* . context)))))
436
    (goto-char (match-end 0)))
Stefan Monnier's avatar
Stefan Monnier committed
437 438
  style)

439 440 441 442 443 444 445
(defun diff-end-of-hunk (&optional style donttrustheader)
  (let (end)
    (when (looking-at diff-hunk-header-re)
      ;; Especially important for unified (because headers are ambiguous).
      (setq style (diff-hunk-style style))
      (goto-char (match-end 0))
      (when (and (not donttrustheader) (match-end 2))
446 447
        (let* ((nold (string-to-number (or (match-string 2) "1")))
               (nnew (string-to-number (or (match-string 4) "1")))
448
               (endold
449 450 451
        (save-excursion
          (re-search-forward (if diff-valid-unified-empty-line
                                 "^[- \n]" "^[- ]")
452 453 454 455 456 457 458 459 460 461 462
                                     nil t nold)
                  (line-beginning-position 2)))
               (endnew
                ;; The hunk may end with a bunch of "+" lines, so the `end' is
                ;; then further than computed above.
                (save-excursion
                  (re-search-forward (if diff-valid-unified-empty-line
                                         "^[+ \n]" "^[+ ]")
                                     nil t nnew)
                  (line-beginning-position 2))))
          (setq end (max endold endnew)))))
463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482
    ;; We may have a first evaluation of `end' thanks to the hunk header.
    (unless end
      (setq end (and (re-search-forward
                      (case style
                        (unified (concat (if diff-valid-unified-empty-line
                                             "^[^-+# \\\n]\\|" "^[^-+# \\]\\|")
                                         ;; A `unified' header is ambiguous.
                                         diff-file-header-re))
                        (context "^[^-+#! \\]")
                        (normal "^[^<>#\\]")
                        (t "^[^-+#!<> \\]"))
                      nil t)
                     (match-beginning 0)))
      (when diff-valid-unified-empty-line
        ;; While empty lines may be valid inside hunks, they are also likely
        ;; to be unrelated to the hunk.
        (goto-char (or end (point-max)))
        (while (eq ?\n (char-before (1- (point))))
          (forward-char -1)
          (setq end (point)))))
483 484
    ;; The return value is used by easy-mmode-define-navigation.
    (goto-char (or end (point-max)))))
485

486 487 488 489
(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."
490 491 492 493 494
  (beginning-of-line)
  (unless (looking-at diff-hunk-header-re)
    (forward-line 1)
    (condition-case ()
	(re-search-backward diff-hunk-header-re)
495 496 497 498 499
      (error
       (if (not try-harder)
           (error "Can't find the beginning of the hunk")
         (diff-beginning-of-file-and-junk)
         (diff-hunk-next))))))
500

501 502 503 504 505 506
(defun diff-unified-hunk-p ()
  (save-excursion
    (ignore-errors
      (diff-beginning-of-hunk)
      (looking-at "^@@"))))

507 508 509
(defun diff-beginning-of-file ()
  (beginning-of-line)
  (unless (looking-at diff-file-header-re)
510 511 512 513 514 515 516 517 518 519 520 521 522
    (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")))))
Lute Kamstra's avatar
Lute Kamstra committed
523

524 525

(defun diff-end-of-file ()
526
  (re-search-forward "^[-+#!<>0-9@* \\]" nil t)
527 528 529 530 531
  (re-search-forward (concat "^[^-+#!<>0-9@* \\]\\|" diff-file-header-re)
		     nil 'move)
  (if (match-beginning 1)
      (goto-char (match-beginning 1))
    (beginning-of-line)))
532

533 534
;; Define diff-{hunk,file}-{prev,next}
(easy-mmode-define-navigation
Stefan Monnier's avatar
Stefan Monnier committed
535
 diff-hunk diff-hunk-header-re "hunk" diff-end-of-hunk diff-restrict-view
536
 (if diff-auto-refine-mode
Stefan Monnier's avatar
Stefan Monnier committed
537 538
     (condition-case-no-debug nil (diff-refine-hunk) (error nil))))

539 540
(easy-mmode-define-navigation
 diff-file diff-file-header-re "file" diff-end-of-hunk)
541 542 543 544 545 546

(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
547
    (if arg (diff-beginning-of-file) (diff-beginning-of-hunk 'try-harder))
548 549 550 551 552 553
    (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))))


554
(defun diff-hunk-kill ()
555 556 557
  "Kill current hunk."
  (interactive)
  (diff-beginning-of-hunk)
558
  (let* ((start (point))
559 560
	 (nexthunk (when (re-search-forward diff-hunk-header-re nil t)
		     (match-beginning 0)))
561 562 563
	 (firsthunk (ignore-errors
		      (goto-char start)
		      (diff-beginning-of-file) (diff-hunk-next) (point)))
564 565
	 (nextfile (ignore-errors (diff-file-next) (point)))
	 (inhibit-read-only t))
566
    (goto-char start)
567 568 569
    (if (and firsthunk (= firsthunk start)
	     (or (null nexthunk)
		 (and nextfile (> nexthunk nextfile))))
570
	;; It's the only hunk for this file, so kill the file.
571
	(diff-file-kill)
572 573 574
      (diff-end-of-hunk)
      (kill-region start (point)))))

575 576
;; "index ", "old mode", "new mode", "new file mode" and
;; "deleted file mode" are output by git-diff.
Lute Kamstra's avatar
Lute Kamstra committed
577
(defconst diff-file-junk-re
578
  "diff \\|index \\|\\(?:deleted file\\|new\\(?: file\\)?\\|old\\) mode")
579

580 581 582 583
(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."
584 585 586 587 588 589 590
  (let* ((orig (point))
         ;; Skip forward over what might be "leading junk" so as to get
         ;; closer to the actual diff.
         (_ (progn (beginning-of-line)
                   (while (looking-at diff-file-junk-re)
                     (forward-line 1))))
         (start (point))
591 592 593 594 595 596 597 598 599 600 601 602 603
         (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
604
                      (forward-line 1)  ;In case we're looking at "Index:".
605 606 607 608 609 610 611 612 613
                      (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))
614 615 616 617 618 619 620 621
          (progn
            (goto-char prevfile)
            ;; Now skip backward over the leading junk we may have before the
            ;; diff itself.
            (while (save-excursion
                     (and (zerop (forward-line -1))
                          (looking-at diff-file-junk-re)))
              (forward-line -1)))
622 623
      ;; File starts *after* the starting point: we really weren't in
      ;; a file diff but elsewhere.
624
      (goto-char orig)
625
      (signal (car err) (cdr err)))))
Lute Kamstra's avatar
Lute Kamstra committed
626

627
(defun diff-file-kill ()
628 629
  "Kill current file's hunks."
  (interactive)
630 631
  (let ((orig (point))
        (start (progn (diff-beginning-of-file-and-junk) (point)))
632
	 (inhibit-read-only t))
633
    (diff-end-of-file)
634
    (if (looking-at "^\n") (forward-char 1)) ;`tla' generates such diffs.
635
    (if (> orig (point)) (error "Not inside a file diff"))
636 637
    (kill-region start (point))))

638 639 640 641 642 643 644 645 646 647 648 649 650 651 652
(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)))))

653 654 655 656 657 658 659
(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)))

660 661 662 663 664 665 666
(defun diff-splittable-p ()
  (save-excursion
    (beginning-of-line)
    (and (looking-at "^[-+ ]")
         (progn (forward-line -1) (looking-at "^[-+ ]"))
         (diff-unified-hunk-p))))

667 668 669 670 671 672
(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))))
673
    (unless (looking-at diff-hunk-header-re-unified)
674 675 676
      (error "diff-split-hunk only works on unified context diffs"))
    (forward-line 1)
    (let* ((start1 (string-to-number (match-string 1)))
677
	   (start2 (string-to-number (match-string 3)))
678
	   (newstart1 (+ start1 (diff-count-matches "^[- \t]" (point) pos)))
679 680
	   (newstart2 (+ start2 (diff-count-matches "^[+ \t]" (point) pos)))
	   (inhibit-read-only t))
681 682 683 684 685 686
      (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))))
687

688

689 690 691 692
;;;;
;;;; jump to other buffers
;;;;

693
(defvar diff-remembered-files-alist nil)
694
(defvar diff-remembered-defdir nil)
695

696 697 698
(defun diff-filename-drop-dir (file)
  (when (string-match "/" file) (substring file (match-end 0))))

699 700 701
(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.
702
The strings are assumed not to contain any \"\\n\" (i.e. end of line).
703 704 705 706 707 708 709 710
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
711
  (let ((str (concat ancestor "\n" from "\n" to)))
712
    (when (and (string-match (concat
713 714
			      "\\`\\(.*?\\)\\(.*\\)\\(.*\\)\n"
			      "\\1\\(.*\\)\\3\n"
715 716 717 718 719 720
			      "\\(.*\\(\\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))))))

721 722 723 724 725 726 727 728
(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))
729
			       nil (diff-find-file-name old 'noprompt) t))))
730 731 732
  (let ((fs (diff-hunk-file-names old)))
    (unless fs (error "No file name to look for"))
    (push (cons fs name) diff-remembered-files-alist)))
733

734 735
(defun diff-hunk-file-names (&optional old)
  "Give the list of file names textually mentioned for the current hunk."
736 737 738 739
  (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)))
740
    (let ((limit (save-excursion
741
		   (condition-case ()
742
		       (progn (diff-hunk-prev) (point))
743
		     (error (point-min)))))
744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761
	  (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)))))))))

762
(defun diff-find-file-name (&optional old noprompt prefix)
763
  "Return the file corresponding to the current patch.
764
Non-nil OLD means that we want the old file.
765
Non-nil NOPROMPT means to prefer returning nil than to prompt the user.
766
PREFIX is only used internally: don't use it."
767 768 769 770
  (unless (equal diff-remembered-defdir default-directory)
    ;; Flush diff-remembered-files-alist if the default-directory is changed.
    (set (make-local-variable 'diff-remembered-defdir) default-directory)
    (set (make-local-variable 'diff-remembered-files-alist) nil))
771 772 773 774 775
  (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)))
776
      (if prefix (setq fs (mapcar (lambda (f) (concat prefix f)) fs)))
777
      (or
778 779 780 781 782 783 784 785 786 787 788 789 790
       ;; 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)))
791 792 793
			       ;; Use file-regular-p to avoid
			       ;; /dev/null, directories, etc.
			       ((or (null file) (file-regular-p file))
794 795 796
				file))))
	    file))
       ;; <foo>.rej patches implicitly apply to <foo>
797 798 799
       (and (string-match "\\.rej\\'" (or buffer-file-name ""))
	    (let ((file (substring buffer-file-name 0 (match-beginning 0))))
	      (when (file-exists-p file) file)))
800 801 802 803 804 805
       ;; 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))
806
	    (diff-find-file-name old noprompt (match-string 1)))
807
       ;; if all else fails, ask the user
808 809 810 811 812 813 814
       (unless noprompt
         (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))
           file))))))
815

816

817 818 819 820
(defun diff-ediff-patch ()
  "Call `ediff-patch-file' on the current buffer."
  (interactive)
  (condition-case err
821
      (ediff-patch-file nil (current-buffer))
822 823
    (wrong-number-of-arguments (ediff-patch-file))))

824
;;;;
825
;;;; Conversion functions
826
;;;;
827 828 829 830 831 832 833

;;(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
834
else cover the whole buffer."
835 836
  (interactive (if (or current-prefix-arg (and transient-mark-mode mark-active))
		   (list (region-beginning) (region-end))
837
		 (list (point-min) (point-max))))
838
  (unless (markerp end) (setq end (copy-marker end t)))
839 840 841 842
  (let (;;(diff-inhibit-after-change t)
	(inhibit-read-only t))
    (save-excursion
      (goto-char start)
843 844 845 846
      (while (and (re-search-forward
                   (concat "^\\(\\(---\\) .+\n\\(\\+\\+\\+\\) .+\\|"
                           diff-hunk-header-re-unified ".*\\)$")
                   nil t)
847 848 849
		  (< (point) end))
	(combine-after-change-calls
	  (if (match-beginning 2)
850
	      ;; we matched a file header
851 852 853 854 855 856
	      (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))
857
		  (lines1 (or (match-string 5) "1"))
858
		  (line2 (match-string 6))
Miles Bader's avatar
Miles Bader committed
859
		  (lines2 (or (match-string 7) "1"))
860 861 862 863 864
		  ;; Variables to use the special undo function.
		  (old-undo buffer-undo-list)
		  (old-end (marker-position end))
		  (start (match-beginning 0))
		  (reversible t))
865 866 867 868
	      (replace-match
	       (concat "***************\n*** " line1 ","
		       (number-to-string (+ (string-to-number line1)
					    (string-to-number lines1)
Miles Bader's avatar
Miles Bader committed
869 870
					    -1))
		       " ****"))
871
	      (save-restriction
872 873 874 875
		(narrow-to-region (line-beginning-position 2)
                                  ;; Call diff-end-of-hunk from just before
                                  ;; the hunk header so it can use the hunk
                                  ;; header info.
876 877 878 879 880 881 882 883 884 885
				  (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
886
			  (?\s (insert " ") (setq modif nil) (backward-char 1))
887 888 889 890 891 892 893 894 895 896
			  (?+ (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)))
897 898
                          ;; diff-valid-unified-empty-line.
                          (?\n (insert "  ") (setq modif nil) (backward-char 2))
899 900 901 902 903 904
			  (t (setq modif nil))))))
		  (goto-char (point-max))
		  (save-excursion
		    (insert "--- " line2 ","
			    (number-to-string (+ (string-to-number line2)
						 (string-to-number lines2)
Miles Bader's avatar
Miles Bader committed
905
						 -1))
906
                            " ----\n" hunk))
907 908 909 910 911
		  ;;(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))
912 913 914 915 916 917 918 919
		      (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))
920 921
		      (while (not (eobp))