diff-mode.el 41.3 KB
Newer Older
1 2
;;; diff-mode.el --- A mode for viewing/editing context diffs

3
;; Copyright (C) 1998, 1999, 2000  Free Software Foundation, Inc.
4 5 6

;; Author: Stefan Monnier <monnier@cs.yale.edu>
;; Keywords: patch diff
7
;; Revision: $Id: diff-mode.el,v 1.30 2000/10/17 12:12:00 eliz Exp $
8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42

;; 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
;; the Free Software Foundation; either version 2, or (at your option)
;; 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
;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
;; Boston, MA 02111-1307, USA.

;;; Commentary:

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

;; inspired by Pavel Machek's patch-mode.el (<pavel@atrey.karlin.mff.cuni.cz>)
;; some efforts were spent to have it somewhat compatible with XEmacs'
;; diff-mode as well as with compilation-minor-mode

;; to use it, simply add to your .emacs the following lines:
;; 
;; (autoload 'diff-mode "diff-mode" "Diff major mode" t)
;; (add-to-list 'auto-mode-alist '("\\.\\(diffs?\\|patch\\|rej\\)\\'" . diff-mode))

;; Bugs:

43
;; - Reverse doesn't work with normal diffs.
44 45 46

;; Todo:

47 48 49 50 51 52 53 54 55 56 57
;; - Spice up the minor-mode with font-lock support.
;; - Improve narrowed-view support.
;; - Improve the `compile' support (?).
;; - Recognize pcl-cvs' special string for `cvs-execute-single'.
;; - Support for # comments in context->unified.
;; - Do a fuzzy search in diff-goto-source.
;; - Allow diff.el to use diff-mode.
;;   This mostly means ability to jump from half-hunk to half-hunk
;;   in context (and normal) diffs and to jump to the corresponding
;;   (i.e. new or old) file.
;; - Handle `diff -b' output in context->unified.
58 59 60 61 62 63 64

;;; Code:

(eval-when-compile (require 'cl))


(defgroup diff-mode ()
65
  "Major mode for viewing/editing diffs"
66
  :version "21.1"
67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85
  :group 'tools
  :group 'diff)

(defcustom diff-jump-to-old-file-flag nil
  "*Non-nil means `diff-goto-source' jumps to the old file.
Else, it jumps to the new file."
  :group 'diff-mode
  :type '(boolean))

(defcustom diff-update-on-the-fly-flag t
  "*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)."
  :group 'diff-mode
  :type '(boolean))

86 87 88 89 90 91
(defcustom diff-advance-after-apply-hunk t
  "*Non-nil means `diff-apply-hunk' will move to the next hunk after applying."
  :group 'diff-mode
  :type 'boolean)


92 93 94 95 96 97 98 99 100 101
(defvar diff-mode-hook nil
  "Run after setting up the `diff-mode' major mode.")

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

;;;; 
;;;; keymap, menu, ...
;;;; 

102
(easy-mmode-defmap diff-mode-shared-map
103
  '(;; From Pavel Machek's patch-mode.
104 105 106 107 108 109
    ("n" . diff-hunk-next)
    ("N" . diff-file-next)
    ("p" . diff-hunk-prev)
    ("P" . diff-file-prev)
    ("k" . diff-hunk-kill)
    ("K" . diff-file-kill)
110
    ;; From compilation-minor-mode.
111 112
    ("}" . diff-file-next)
    ("{" . diff-file-prev)
113
    ("\C-m" . diff-goto-source)
114
    ([mouse-2] . diff-mouse-goto-source)
115
    ;; From XEmacs' diff-mode.
116 117 118 119 120 121 122 123 124 125 126
    ("W" . widen)
    ;;("." . 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)
    (" " . scroll-up)
    ("\177" . scroll-down)
127
    ;; Our very own bindings.
128 129 130 131 132
    ("A" . diff-ediff-patch)
    ("r" . diff-restrict-view)
    ("R" . diff-reverse-direction)
    ("U" . diff-context->unified)
    ("C" . diff-unified->context))
133
  "Basic keymap for `diff-mode', bound to various prefix keys.")
134

135
(easy-mmode-defmap diff-mode-map
136
  `(("\e" . ,diff-mode-shared-map)
137 138 139
    ;; From compilation-minor-mode.
    ("\C-c\C-c" . diff-goto-source)
    ;; Misc operations.
140 141
    ("\C-c\C-a" . diff-apply-hunk)
    ("\C-c\C-t" . diff-test-hunk))
142 143 144 145 146 147 148 149 150 151 152 153 154 155
  "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]
    ["Apply with Ediff"		diff-ediff-patch	t]
    ["-----" nil nil]
    ["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)]
    ))

156
(defcustom diff-minor-mode-prefix "\C-c="
157 158
  "Prefix key for `diff-minor-mode' commands."
  :group 'diff-mode
159
  :type '(choice (string "\e") (string "C-c=") string))
160

161 162
(easy-mmode-defmap diff-minor-mode-map
  `((,diff-minor-mode-prefix . ,diff-mode-shared-map))
163 164
  "Keymap for `diff-minor-mode'.  See also `diff-mode-shared-map'.")

165 166 167 168 169

;;;; 
;;;; font-lock support
;;;; 

Stefan Monnier's avatar
Stefan Monnier committed
170
(defface diff-header-face
171 172 173 174 175
  '((((type tty pc) (class color) (background light))
     (:foreground "lightblue"))
    (((type tty pc) (class color) (background dark))
     (:foreground "green"))
    (((class color) (background light))
176
     (:background "grey85"))
177 178
    (((class color) (background dark))
     (:background "grey45"))
179
    (t (:bold t)))
180
  "`diff-mode' face inherited by hunk and index header faces."
Stefan Monnier's avatar
Stefan Monnier committed
181 182 183
  :group 'diff-mode)
(defvar diff-header-face 'diff-header-face)

184
(defface diff-file-header-face
185 186 187 188 189
  '((((type tty pc) (class color) (background light))
     (:foreground "yellow"))
    (((type tty pc) (class color) (background dark))
     (:foreground "cyan"))
    (((class color) (background light))
190
     (:background "grey70" :bold t))
191 192
    (((class color) (background dark))
     (:background "grey60" :bold t))
193
    (t (:bold t)))			; :height 1.3
Stefan Monnier's avatar
Stefan Monnier committed
194
  "`diff-mode' face used to highlight file header lines."
195 196 197 198
  :group 'diff-mode)
(defvar diff-file-header-face 'diff-file-header-face)

(defface diff-index-face
Stefan Monnier's avatar
Stefan Monnier committed
199 200
  '((t (:inherit diff-file-header-face)))
  "`diff-mode' face used to highlight index header lines."
201 202 203 204
  :group 'diff-mode)
(defvar diff-index-face 'diff-index-face)

(defface diff-hunk-header-face
Stefan Monnier's avatar
Stefan Monnier committed
205 206
  '((t (:inherit diff-header-face)))
  "`diff-mode' face used to highlight hunk header lines."
207 208 209 210
  :group 'diff-mode)
(defvar diff-hunk-header-face 'diff-hunk-header-face)

(defface diff-removed-face
Stefan Monnier's avatar
Stefan Monnier committed
211 212
  '((t (:inherit diff-changed-face)))
  "`diff-mode' face used to highlight removed lines."
213 214 215 216
  :group 'diff-mode)
(defvar diff-removed-face 'diff-removed-face)

(defface diff-added-face
Stefan Monnier's avatar
Stefan Monnier committed
217 218
  '((t (:inherit diff-changed-face)))
  "`diff-mode' face used to highlight added lines."
219 220 221 222
  :group 'diff-mode)
(defvar diff-added-face 'diff-added-face)

(defface diff-changed-face
223 224 225 226 227
  '((((type tty pc) (class color) (background light))
     (:foreground "magenta"))
    (((type tty pc) (class color) (background dark))
     (:foreground "yellow"))
    (t ()))
Stefan Monnier's avatar
Stefan Monnier committed
228
  "`diff-mode' face used to highlight changed lines."
229 230 231
  :group 'diff-mode)
(defvar diff-changed-face 'diff-changed-face)

232 233 234 235 236 237
(defface diff-context-face
  '((((class color) (background light))
     (:foreground "grey50"))
    (((class color) (background dark))
     (:foreground "grey70"))
    (t ))
Stefan Monnier's avatar
Stefan Monnier committed
238 239
  "`diff-mode' face used to highlight context and other side-information."
  :group 'diff-mode)
240
(defvar diff-context-face 'diff-context-face)
Stefan Monnier's avatar
Stefan Monnier committed
241

242
(defvar diff-font-lock-keywords
Stefan Monnier's avatar
Stefan Monnier committed
243
  '(("^\\(@@ -[0-9,]+ \\+[0-9,]+ @@\\)\\(.*\\)$" ;unified
244
     (1 diff-hunk-header-face)
245
     (2 diff-context-face))
Stefan Monnier's avatar
Stefan Monnier committed
246 247 248
    ("^--- .+ ----$"		;context
     . diff-hunk-header-face)
    ("\\(\\*\\{15\\}\\)\\(.*\\)$"	;context
249
     (1 diff-hunk-header-face)
250
     (2 diff-context-face))
251
    ("^\\*\\*\\* .+ \\*\\*\\*\\*". diff-hunk-header-face) ;context
252
    ("^\\(---\\|\\+\\+\\+\\|\\*\\*\\*\\) \\(\\S-+\\)\\(.*[^*-]\\)?\n"
Stefan Monnier's avatar
Stefan Monnier committed
253
     (0 diff-header-face) (2 diff-file-header-face prepend))
254 255 256 257
    ("^[0-9,]+[acd][0-9,]+$" . diff-hunk-header-face)
    ("^!.*\n" . diff-changed-face)	;context
    ("^[+>].*\n" . diff-added-face)
    ("^[-<].*\n" . diff-removed-face)
Stefan Monnier's avatar
Stefan Monnier committed
258
    ("^Index: \\(.+\\).*\n" (0 diff-header-face) (1 diff-index-face prepend))
259
    ("^#.*" . font-lock-string-face)
260
    ("^[^-=+*!<>].*\n" . diff-context-face)))
261 262

(defconst diff-font-lock-defaults
263
  '(diff-font-lock-keywords t nil nil nil (font-lock-multiline . nil)))
264

265 266 267 268 269 270
(defvar diff-imenu-generic-expression
  ;; Prefer second name as first is most likely to be a backup or
  ;; version-control name.
  '((nil "\\+\\+\\+\\ \\([^\t\n]+\\)\t" 1) ; unidiffs
    (nil "^--- \\([^\t\n]+\\)\t.*\n\\*" 1))) ; context diffs

271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286
;;;;
;;;; Compile support
;;;;

(defvar diff-file-regexp-alist
  '(("Index: \\(.+\\)" 1)))

(defvar diff-error-regexp-alist
  '(("@@ -\\([0-9]+\\),[0-9]+ \\+\\([0-9]+\\),[0-9]+ @@" nil 2)
    ("--- \\([0-9]+\\),[0-9]+ ----" nil 1)
    ("\\([0-9]+\\)\\(,[0-9]+\\)?[adc]\\([0-9]+\\)" nil 3)))

;;;; 
;;;; Movement
;;;; 

287
(defconst diff-hunk-header-re "^\\(@@ -[0-9,]+ \\+[0-9,]+ @@.*\\|\\*\\{15\\}.*\n\\*\\*\\* .+ \\*\\*\\*\\*\\|[0-9]+\\(,[0-9]+\\)?[acd][0-9]+\\(,[0-9]+\\)?\\)$")
288 289 290 291 292
(defconst diff-file-header-re (concat "^\\(--- .+\n\\+\\+\\+\\|\\*\\*\\* .+\n---\\|[^-+!<>0-9@* ]\\).+\n" (substring diff-hunk-header-re 1)))
(defvar diff-narrowed-to nil)

(defun diff-end-of-hunk (&optional style)
  (if (looking-at diff-hunk-header-re) (goto-char (match-end 0)))
293 294 295 296 297 298 299 300 301
  (let ((end (and (re-search-forward (case style
				       (unified "^[^-+# \\]")
				       (context "^[^-+#! \\]")
				       (normal "^[^<>#\\]")
				       (t "^[^-+#!<> \\]"))
				     nil t)
		  (match-beginning 0))))
    ;; The return value is used by easy-mmode-define-navigation.
    (goto-char (or end (point-max)))))
302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319

(defun diff-beginning-of-hunk ()
  (beginning-of-line)
  (unless (looking-at diff-hunk-header-re)
    (forward-line 1)
    (condition-case ()
	(re-search-backward diff-hunk-header-re)
      (error (error "Can't find the beginning of the hunk")))))

(defun diff-beginning-of-file ()
  (beginning-of-line)
  (unless (looking-at diff-file-header-re)
    (forward-line 2)
    (condition-case ()
	(re-search-backward diff-file-header-re)
      (error (error "Can't find the beginning of the file")))))

(defun diff-end-of-file ()
320 321
  (re-search-forward "^[-+#!<>0-9@* \\]" nil t)
  (re-search-forward "^[^-+#!<>0-9@* \\]" nil 'move)
322 323
  (beginning-of-line))

324 325 326 327 328
;; Define diff-{hunk,file}-{prev,next}
(easy-mmode-define-navigation
 diff-hunk diff-hunk-header-re "hunk" diff-end-of-hunk)
(easy-mmode-define-navigation
 diff-file diff-file-header-re "file" diff-end-of-hunk)
329 330 331 332 333 334 335 336 337 338 339 340 341

(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
    (if arg (diff-beginning-of-file) (diff-beginning-of-hunk))
    (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))))


342
(defun diff-hunk-kill ()
343 344 345 346 347 348
  "Kill current hunk."
  (interactive)
  (diff-beginning-of-hunk)
  (let ((start (point))
	(firsthunk (save-excursion
		     (ignore-errors
349
		       (diff-beginning-of-file) (diff-hunk-next) (point))))
350 351
	(nexthunk  (save-excursion
		     (ignore-errors
352
		       (diff-hunk-next) (point))))
353 354
	(nextfile (save-excursion
		    (ignore-errors
355
		      (diff-file-next) (point)))))
356 357 358 359
    (if (and firsthunk (= firsthunk start)
	     (or (null nexthunk)
		 (and nextfile (> nexthunk nextfile))))
	;; we're the only hunk for this file, so kill the file
360
	(diff-file-kill)
361 362 363
      (diff-end-of-hunk)
      (kill-region start (point)))))

364
(defun diff-file-kill ()
365 366 367 368 369 370
  "Kill current file's hunks."
  (interactive)
  (diff-beginning-of-file)
  (let* ((start (point))
	 (prevhunk (save-excursion
		     (ignore-errors
371
		       (diff-hunk-prev) (point))))
372 373 374 375 376 377
	 (index (save-excursion
		  (re-search-backward "^Index: " prevhunk t))))
    (when index (setq start index))
    (diff-end-of-file)
    (kill-region start (point))))

378 379 380 381 382 383 384 385 386 387 388 389 390 391 392
(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)))))

393 394 395 396
;;;;
;;;; jump to other buffers
;;;;

397 398
(defvar diff-remembered-files-alist nil)

399 400 401
(defun diff-filename-drop-dir (file)
  (when (string-match "/" file) (substring file (match-end 0))))

402 403 404
(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.
405
The strings are assumed not to contain any \"\\n\" (i.e. end of line).
406 407 408 409 410 411 412 413
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
414
  (let ((str (concat ancestor "\n" from "\n" to)))
415
    (when (and (string-match (concat
416 417
			      "\\`\\(.*?\\)\\(.*\\)\\(.*\\)\n"
			      "\\1\\(.*\\)\\3\n"
418 419 420 421 422 423
			      "\\(.*\\(\\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))))))

424 425 426 427 428 429 430 431 432
(defun diff-find-file-name (&optional old)
  "Return the file corresponding to the current patch.
Non-nil OLD means that we want the old file."
  (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* ((limit (save-excursion
		   (condition-case ()
433
		       (progn (diff-hunk-prev) (point))
434
		     (error (point-min)))))
435
	   (header-files
436
	    (if (looking-at "[-*][-*][-*] \\(\\S-+\\)\\(\\s-.*\\)?\n[-+][-+][-+] \\(\\S-+\\)")
437 438 439
		(list (if old (match-string 1) (match-string 2))
		      (if old (match-string 2) (match-string 1)))
	      (forward-line 1) nil))
440 441 442 443
	   (fs (append
		(when (save-excursion
			(re-search-backward "^Index: \\(.+\\)" limit t))
		  (list (match-string 1)))
444
		header-files
445 446 447
		(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))))))
448
	   (fs (delq nil fs)))
449
      (or
450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466
       ;; 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)))
			       ((or (null file) (file-exists-p file))
				file))))
	    file))
       ;; <foo>.rej patches implicitly apply to <foo>
467 468 469
       (and (string-match "\\.rej\\'" (or buffer-file-name ""))
	    (let ((file (substring buffer-file-name 0 (match-beginning 0))))
	      (when (file-exists-p file) file)))
470 471 472 473 474
       ;; 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))
475 476
	 file)))))

477

478 479 480 481 482 483
(defun diff-mouse-goto-source (event)
  "Run `diff-goto-source' for the diff at a mouse click."
  (interactive "e")
  (save-excursion
    (mouse-set-point event)
    (diff-goto-source)))
484

485

486 487 488 489
(defun diff-ediff-patch ()
  "Call `ediff-patch-file' on the current buffer."
  (interactive)
  (condition-case err
490
      (ediff-patch-file nil (current-buffer))
491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511
    (wrong-number-of-arguments (ediff-patch-file))))

;;;; 
;;;; Conversion functions
;;;; 

;;(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
else cover the whole bufer."
  (interactive (if current-prefix-arg
		   (list (mark) (point))
		 (list (point-min) (point-max))))
  (unless (markerp end) (setq end (copy-marker end)))
  (let (;;(diff-inhibit-after-change t)
	(inhibit-read-only t))
    (save-excursion
      (goto-char start)
512
      (while (and (re-search-forward "^\\(\\(---\\) .+\n\\(\\+\\+\\+\\) .+\\|@@ -\\([0-9]+\\),\\([0-9]+\\) \\+\\([0-9]+\\),\\([0-9]+\\) @@.*\\)$" nil t)
513 514 515
		  (< (point) end))
	(combine-after-change-calls
	  (if (match-beginning 2)
516
	      ;; we matched a file header
517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598
	      (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))
		  (lines2 (match-string 7)))
	      (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)
			  (?  (insert " ") (setq modif nil) (backward-char 1))
			  (?+ (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))
		      (while (not (eobp))
			(case (char-after)
			  (?  (insert " ") (setq modif nil) (backward-char 1))
			  (?- (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))
			    (setq delete nil)))))))))))))))

(defun diff-context->unified (start end)
  "Convert context diffs to unified diffs.
START and END are either taken from the region (if a prefix arg is given) or
else cover the whole bufer."
  (interactive (if current-prefix-arg
		   (list (mark) (point))
		 (list (point-min) (point-max))))
  (unless (markerp end) (setq end (copy-marker end)))
  (let (;;(diff-inhibit-after-change t)
	(inhibit-read-only t))
    (save-excursion
      (goto-char start)
599
      (while (and (re-search-forward "^\\(\\(\\*\\*\\*\\) .+\n\\(---\\) .+\\|\\*\\{15\\}.*\n\\*\\*\\* \\([0-9]+\\),\\(-?[0-9]+\\) \\*\\*\\*\\*\\)$" nil t)
600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670
		  (< (point) end))
	(combine-after-change-calls
	  (if (match-beginning 2)
	      ;; we matched a file header
	      (progn
		;; use reverse order to make sure the indices are kept valid
		(replace-match "+++" t t nil 3)
		(replace-match "---" t t nil 2))
	    ;; we matched a hunk header
	    (let ((line1s (match-string 4))
		  (line1e (match-string 5))
		  (pt1 (match-beginning 0)))
	      (replace-match "")
	      (unless (re-search-forward
		       "^--- \\([0-9]+\\),\\(-?[0-9]+\\) ----$" 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))
		    (?\ 		;merge with the other half of the chunk
		     (let* ((endline2
			     (save-excursion
			       (goto-char pt2) (forward-line 1) (point)))
			    (c (char-after pt2)))
		       (case c
			 ((?! ?+)
			  (insert "+"
				  (prog1 (buffer-substring (+ pt2 2) endline2)
				    (delete-region pt2 endline2))))
			 (?\ 		;FIXME: check consistency
			  (delete-region pt2 endline2)
			  (delete-char 1)
			  (forward-line 1))
			 (?\\ (forward-line 1))
			 (t (delete-char 1) (forward-line 1)))))
		    (t (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)) " @@"))))))))))

(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
else cover the whole bufer."
  (interactive (if current-prefix-arg
		   (list (mark) (point))
		 (list (point-min) (point-max))))
  (unless (markerp end) (setq end (copy-marker end)))
  (let (;;(diff-inhibit-after-change t)
	(inhibit-read-only t))
    (save-excursion
      (goto-char start)
671
      (while (and (re-search-forward "^\\(\\([-*][-*][-*] \\)\\(.+\\)\n\\([-+][-+][-+] \\)\\(.+\\)\\|\\*\\{15\\}.*\n\\*\\*\\* \\(.+\\) \\*\\*\\*\\*\\|@@ -\\([0-9,]+\\) \\+\\([0-9,]+\\) @@.*\\)$" nil t)
672 673 674 675 676 677 678 679 680 681 682 683
		  (< (point) end))
	(combine-after-change-calls
	  (cond
	   ;; a file header
	   ((match-beginning 2) (replace-match "\\2\\5\n\\4\\3" nil))
	   ;; a context-diff hunk header
	   ((match-beginning 6)
	    (let ((pt-lines1 (match-beginning 6))
		  (lines1 (match-string 6)))
	      (replace-match "" nil nil nil 6)
	      (forward-line 1)
	      (let ((half1s (point)))
684
		(while (looking-at "[-! \\][ \t]\\|#")
685 686
		  (when (= (char-after) ?-) (delete-char 1) (insert "+"))
		  (forward-line 1))
687
		(let ((half1 (delete-and-extract-region half1s (point))))
688 689 690 691 692 693 694
		  (unless (looking-at "^--- \\([0-9]+,-?[0-9]+\\) ----$")
		    (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)))
695
		      (while (looking-at "[!+ \\][ \t]\\|#")
696 697
			(when (= (char-after) ?+) (delete-char 1) (insert "-"))
			(forward-line 1))
698
		      (let ((half2 (delete-and-extract-region half2s (point))))
699
			(insert (or half1 ""))
700
			(goto-char half1s)
701
			(insert (or half2 ""))))
702 703 704 705 706 707 708 709 710 711 712 713
		    (goto-char pt-lines1)
		    (insert str1))))))
	   ;; a unified-diff hunk header
	   ((match-beginning 7)
	    (replace-match "@@ -\\8 +\\7 @@" nil)
	    (forward-line 1)
	    (let ((c (char-after)) first last)
	      (while (case (setq c (char-after))
		       (?- (setq first (or first (point)))
			   (delete-char 1) (insert "+") t)
		       (?+ (setq last (or last (point)))
			   (delete-char 1) (insert "-") t)
714
		       ((?\\ ?#) t)
715
		       (t (when (and first last (< first last))
716 717 718
			    (let ((str
				   (save-excursion
				     (delete-and-extract-region first last))))
719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735
			      (insert str)))
			  (setq first nil last nil)
			  (equal ?\  c)))
		(forward-line 1))))))))))

(defun diff-fixup-modifs (start end)
  "Fixup the hunk headers (in case the buffer was modified).
START and END are either taken from the region (if a prefix arg is given) or
else cover the whole bufer."
  (interactive (if current-prefix-arg
		   (list (mark) (point))
		 (list (point-min) (point-max))))
  (let ((inhibit-read-only t))
    (save-excursion
      (goto-char end) (diff-end-of-hunk)
      (let ((plus 0) (minus 0) (space 0) (bang 0))
	(while (and (= (forward-line -1) 0) (<= start (point)))
736
	  (if (not (looking-at "\\(@@ -[0-9,]+ \\+[0-9,]+ @@.*\\|[-*][-*][-*] .+ [-*][-*][-*][-*]\\)$"))
737 738 739 740 741
	      (case (char-after)
		(?\  (incf space))
		(?+ (incf plus))
		(?- (incf minus))
		(?! (incf bang))
742
		((?\\ ?#) nil)
743 744
		(t  (setq space 0 plus 0 minus 0 bang 0)))
	    (cond
745
	     ((looking-at "@@ -[0-9]+,\\([0-9]*\\) \\+[0-9]+,\\([0-9]*\\) @@.*$")
746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783
	      (let* ((old1 (match-string 1))
		     (old2 (match-string 2))
		     (new1 (number-to-string (+ space minus)))
		     (new2 (number-to-string (+ space plus))))
		(unless (string= new2 old2) (replace-match new2 t t nil 2))
		(unless (string= new1 old1) (replace-match new1 t t nil 1))))
	     ((looking-at "--- \\([0-9]+\\),\\([0-9]*\\) ----$")
	      (when (> (+ space bang plus) 0)
		(let* ((old1 (match-string 1))
		       (old2 (match-string 2))
		       (new (number-to-string
			     (+ space bang plus -1 (string-to-number old1)))))
		  (unless (string= new old2) (replace-match new t t nil 2)))))
	     ((looking-at "\\*\\*\\* \\([0-9]+\\),\\(-?[0-9]*\\) \\*\\*\\*\\*$")
	      (when (> (+ space bang minus) 0)
		(let* ((old (match-string 1))
		       (new (format
			     (concat "%0" (number-to-string (length old)) "d")
			     (+ space bang minus -1 (string-to-number old)))))
		  (unless (string= new old) (replace-match new t t nil 2))))))
	    (setq space 0 plus 0 minus 0 bang 0)))))))

;;;; 
;;;; Hooks
;;;; 

(defun diff-write-contents-hooks ()
  "Fixup hunk headers if necessary."
  (if (buffer-modified-p) (diff-fixup-modifs (point-min) (point-max)))
  nil)

;; It turns out that making changes in the buffer from within an
;; *-change-function is asking for trouble, whereas making them
;; from a post-command-hook doesn't pose much problems
(defvar diff-unhandled-changes nil)
(defun diff-after-change-function (beg end len)
  "Remember to fixup the hunk header.
See `after-change-functions' for the meaning of BEG, END and LEN."
784 785 786 787 788
  ;; Ignoring changes when inhibit-read-only is set is strictly speaking
  ;; incorrect, but it turns out that inhibit-read-only is normally not set
  ;; inside editing commands, while it tends to be set when the buffer gets
  ;; updated by an async process or by a conversion function, both of which
  ;; would rather not be uselessly slowed down by this hook.
789 790 791 792 793 794 795 796 797 798 799 800
  (when (and (not undo-in-progress) (not inhibit-read-only))
    (if diff-unhandled-changes
	(setq diff-unhandled-changes
	      (cons (min beg (car diff-unhandled-changes))
		    (max beg (cdr diff-unhandled-changes))))
      (setq diff-unhandled-changes (cons beg end)))))

(defun diff-post-command-hook ()
  "Fixup hunk headers if necessary."
  (when (consp diff-unhandled-changes)
    (ignore-errors
      (save-excursion
801 802 803 804 805 806 807 808 809
	(goto-char (car diff-unhandled-changes))
	(unless (ignore-errors
		  (diff-beginning-of-hunk)
		  (save-excursion
		    (diff-end-of-hunk)
		    (> (point) (car diff-unhandled-changes))))
	  (goto-char (car diff-unhandled-changes))
	  (re-search-forward diff-hunk-header-re (cdr diff-unhandled-changes))
	  (diff-beginning-of-hunk))
810 811 812 813 814 815 816 817
	(diff-fixup-modifs (point) (cdr diff-unhandled-changes))))
    (setq diff-unhandled-changes nil)))

;;;; 
;;;; The main function
;;;; 

;;;###autoload
818
(define-derived-mode diff-mode fundamental-mode "Diff"
819
  "Major mode for viewing/editing context diffs.
820 821 822 823 824 825
Supports unified and context diffs as well as (to a lesser extent) normal diffs.
When the buffer is read-only, the ESC prefix is not necessary.
This mode runs `diff-mode-hook'.
\\{diff-mode-map}"
  (set (make-local-variable 'font-lock-defaults) diff-font-lock-defaults)
  (set (make-local-variable 'outline-regexp) diff-outline-regexp)
826 827
  (set (make-local-variable 'imenu-generic-expression)
       diff-imenu-generic-expression)
828 829 830 831 832 833 834 835 836 837
  ;; These are not perfect.  They would be better done separately for
  ;; context diffs and unidiffs.
  ;; (set (make-local-variable 'paragraph-start)
  ;;        (concat "@@ "			; unidiff hunk
  ;; 	       "\\|\\*\\*\\* "		; context diff hunk or file start
  ;; 	       "\\|--- [^\t]+\t"))	; context or unidiff file
  ;; 					; start (first or second line)
  ;;   (set (make-local-variable 'paragraph-separate) paragraph-start)
  ;;   (set (make-local-variable 'page-delimiter) "--- [^\t]+\t")
  ;; compile support
838 839 840 841 842 843 844 845
  (set (make-local-variable 'compilation-file-regexp-alist)
       diff-file-regexp-alist)
  (set (make-local-variable 'compilation-error-regexp-alist)
       diff-error-regexp-alist)
  (when (string-match "\\.rej\\'" (or buffer-file-name ""))
    (set (make-local-variable 'compilation-current-file)
	 (substring buffer-file-name 0 (match-beginning 0))))
  (compilation-shell-minor-mode 1)
846 847
  ;; setup change hooks
  (toggle-read-only t)
848 849 850
  (if (not diff-update-on-the-fly-flag)
      (add-hook 'write-contents-hooks 'diff-write-contents-hooks)
    (make-local-variable 'diff-unhandled-changes)
851 852
    (add-hook 'after-change-functions 'diff-after-change-function nil t)
    (add-hook 'post-command-hook 'diff-post-command-hook nil t))
853
  ;; Neat trick from Dave Love to add more bindings in read-only mode:
854
  (add-to-list (make-local-variable 'minor-mode-overriding-map-alist)
855 856 857 858
  	       (cons 'buffer-read-only diff-mode-shared-map))
  ;; add-log support
  (set (make-local-variable 'add-log-current-defun-function)
       'diff-current-defun)
859 860
  (set (make-local-variable 'add-log-buffer-file-name-function)
       'diff-find-file-name))
861 862

;;;###autoload
863 864 865 866 867
(define-minor-mode diff-minor-mode
  "Minor mode for viewing/editing context diffs.
\\{diff-minor-mode-map}"
  nil " Diff" nil
  ;; FIXME: setup font-lock
868 869 870 871
  ;; setup change hooks
  (if (not diff-update-on-the-fly-flag)
      (add-hook 'write-contents-hooks 'diff-write-contents-hooks)
    (make-local-variable 'diff-unhandled-changes)
872 873
    (add-hook 'after-change-functions 'diff-after-change-function nil t)
    (add-hook 'post-command-hook 'diff-post-command-hook nil t)))
874

875

876 877 878 879 880 881 882 883 884 885 886 887 888 889
;;;
;;; Misc operations that have proved useful at some point.
;;;

(defun diff-next-complex-hunk ()
  "Jump to the next \"complex\" hunk.
\"Complex\" is approximated by \"the hunk changes the number of lines\".
Only works for unified diffs."
  (interactive)
  (while
      (and (re-search-forward "^@@ [-0-9]+,\\([0-9]+\\) [+0-9]+,\\([0-9]+\\) @@"
			      nil t)
	   (equal (match-string 1) (match-string 2)))))

890
(defun diff-hunk-text (hunk destp &optional char-offset)
891
  "Return the literal source text from HUNK.
Stefan Monnier's avatar
Stefan Monnier committed
892
if DESTP is nil return the source, otherwise the destination text.
893
If CHAR-OFFSET is non-nil, it should be a char-offset in
Miles Bader's avatar
Miles Bader committed
894
HUNK, and instead of a string, a cons cell is returned whose car is the
895
appropriate text, and whose cdr is the corresponding char-offset in that text."
896
  (with-temp-buffer
897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970
    (insert hunk)
    (goto-char (point-min))
    (let ((src-pos nil)
	  (dst-pos nil)
	  (divider-pos nil)
	  (num-pfx-chars 2))
      ;; Set the following variables:
      ;;  SRC-POS     buffer pos of the source part of the hunk or nil if none
      ;;  DST-POS     buffer pos of the destination part of the hunk or nil
      ;;  DIVIDER-POS buffer pos of any divider line separating the src & dst
      ;;  NUM-PFX-CHARS  number of line-prefix characters used by this format"
      (cond ((looking-at "^@@")
	     ;; unified diff
	     (setq num-pfx-chars 1)
	     (forward-line 1)
	     (setq src-pos (point) dst-pos (point)))
	    ((looking-at "^\\*\\*")
	     ;; context diff
	     (forward-line 2)
	     (setq src-pos (point))
	     (re-search-forward "^--- " nil t)
	     (forward-line 0)
	     (setq divider-pos (point))
	     (forward-line 1)
	     (setq dst-pos (point)))
	    ((looking-at "^[0-9]+a[0-9,]+$")
	     ;; normal diff, insert
	     (forward-line 1)
	     (setq dst-pos (point)))
	    ((looking-at "^[0-9,]+d[0-9]+$")
	     ;; normal diff, delete
	     (forward-line 1)
	     (setq src-pos (point)))
	    ((looking-at "^[0-9,]+c[0-9,]+$")
	     ;; normal diff, change
	     (forward-line 1)
	     (setq src-pos (point))
	     (re-search-forward "^---$" nil t)
	     (forward-line 0)
	     (setq divider-pos (point))
	     (forward-line 1)
	     (setq dst-pos (point)))
	    (t
	     (error "Unknown diff hunk type")))

      (if (if destp (null dst-pos) (null src-pos))
	  ;; Implied empty text
	  (if char-offset '("" . 0) "")

	;; For context diffs, either side can be empty, (if there's only
	;; added or only removed text).  We should then use the other side.
	(cond ((equal src-pos divider-pos) (setq src-pos dst-pos))
	      ((equal dst-pos (point-max)) (setq dst-pos src-pos)))

	(when char-offset (goto-char (+ (point-min) char-offset)))

	;; Get rid of anything except the desired text.
	(save-excursion
	  ;; Delete unused text region
	  (let ((keep (if destp dst-pos src-pos)))
	    (when (and divider-pos (> divider-pos keep))
	      (delete-region divider-pos (point-max)))
	    (delete-region (point-min) keep))
	  ;; Remove line-prefix characters, and unneeded lines (unified diffs).
	  (let ((kill-char (if destp ?- ?+)))
	    (goto-char (point-min))
	    (while (not (eobp))
	      (if (eq (char-after) kill-char)
		  (delete-region (point) (progn (forward-line 1) (point)))
		(delete-char num-pfx-chars)
		(forward-line 1)))))

	(let ((text (buffer-substring-no-properties (point-min) (point-max))))
	  (if char-offset (cons text (- (point) (point-min))) text))))))
971

972

Stefan Monnier's avatar
Stefan Monnier committed
973
(defun diff-find-text (text)
974
  "Return the buffer position of the nearest occurrence of TEXT.
975 976 977
If TEXT isn't found, nil is returned."
  (let* ((orig (point))
	 (forw (and (search-forward text nil t)
978
			  (match-beginning 0)))
979 980
	 (back (and (goto-char (+ orig (length text)))
		    (search-backward text nil t)
981 982
			  (match-beginning 0))))
	  ;; Choose the closest match.
983 984 985 986
    (if (and forw back)
	(if (> (- forw orig) (- orig back)) back forw)
      (or back forw))))

987 988
(defsubst diff-xor (a b) (if a (not b) b))

Stefan Monnier's avatar
Stefan Monnier committed
989
(defun diff-find-source-location (&optional other-file reverse)
990
  "Find out (BUF LINE-OFFSET POS SRC DST SWITCHED)."
Stefan Monnier's avatar
Stefan Monnier committed
991
  (save-excursion
992 993 994 995 996 997
    (let* ((other (diff-xor other-file diff-jump-to-old-file-flag))
	   (char-offset (- (point) (progn (diff-beginning-of-hunk) (point))))
	   (hunk (buffer-substring (point)
				   (save-excursion (diff-end-of-hunk) (point))))
	   (old (diff-hunk-text hunk reverse char-offset))
	   (new (diff-hunk-text hunk (not reverse) char-offset))
Stefan Monnier's avatar
Stefan Monnier committed
998
	   ;; Find the location specification.
Stefan Monnier's avatar
Stefan Monnier committed
999
	   (line (if (not (looking-at "\\(?:\\*\\{15\\}.*\n\\)?[-@* ]*\\([0-9,]+\\)\\([ acd+]+\\([0-9,]+\\)\\)?"))
1000 1001 1002 1003 1004 1005 1006 1007
		     (error "Can't find the hunk header")
		   (if other (match-string 1)
		     (if (match-end 3) (match-string 3)
		       (unless (re-search-forward "^--- \\([0-9,]+\\)" nil t)
			 (error "Can't find the hunk separator"))
		       (match-string 1)))))
	   (file (or (diff-find-file-name other) (error "Can't find the file")))
	   (buf (find-file-noselect file)))
Stefan Monnier's avatar
Stefan Monnier committed
1008 1009
      ;; Update the user preference if he so wished.
      (when (> (prefix-numeric-value other-file) 8)
1010
	(setq diff-jump-to-old-file-flag other))
Stefan Monnier's avatar
Stefan Monnier committed
1011 1012 1013 1014 1015 1016 1017
      (with-current-buffer buf
	(goto-line (string-to-number line))
	(let* ((orig-pos (point))
	       (pos (diff-find-text (car old)))
	       (switched nil))
	  (when (null pos)
	    (setq pos (diff-find-text (car new)) switched t))
1018 1019 1020 1021 1022
	  (nconc
	   (list buf)
	   (if pos (list (count-lines orig-pos pos) pos) (list nil orig-pos))
	   (if switched (list new old t) (list old new))))))))

Stefan Monnier's avatar
Stefan Monnier committed
1023

1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035
(defun diff-hunk-status-msg (line-offset reversed dry-run)
  (let ((msg (if dry-run
		 (if reversed "already applied" "not yet applied")
	       (if reversed "undone" "applied"))))
    (message (cond ((null line-offset) "Hunk text not found")
		   ((= line-offset 0) "Hunk %s")
		   ((= line-offset 1) "Hunk %s at offset %d line")
		   (t "Hunk %s at offset %d lines"))
	     msg line-offset)))


(defun diff-apply-hunk (&optional reverse)
1036
  "Apply the current hunk to the source file and go to the next.
1037 1038 1039 1040 1041
By default, the new source file is patched, but if the variable
`diff-jump-to-old-file-flag' is non-nil, then the old source file is
patched instead (some commands, such as `diff-goto-source' can change
the value of this variable when given an appropriate prefix argument).

1042
With a prefix argument, REVERSE the hunk."
1043
  (interactive "P")
1044
  (destructuring-bind (buf line-offset pos old new &optional switched)
1045 1046
      (diff-find-source-location nil reverse)
    (cond
1047 1048
     ((null line-offset)
      (error "Can't find the text to patch"))
1049 1050 1051 1052 1053 1054 1055 1056 1057
     ((and switched
	   ;; A reversed patch was detected, perhaps apply it in reverse
	   (not (save-window-excursion
		  (pop-to-buffer buf)
		  (goto-char (+ pos (cdr old)))
		  (y-or-n-p
		   (if reverse
		       "Hunk hasn't been applied yet; apply it now? "
		     "Hunk has already been applied; undo it? ")))))
1058
      (message "(Nothing done)"))
1059
     (t
1060 1061 1062 1063 1064 1065 1066 1067 1068 1069
      ;; Apply the hunk
      (with-current-buffer buf
	(goto-char pos)
	(delete-char (length (car old)))
	(insert (car new)))
      ;; Display BUF in a window
      (set-window-point (display-buffer buf) (+ pos (cdr new)))
      (diff-hunk-status-msg line-offset (diff-xor switched reverse) nil)
      (when diff-advance-after-apply-hunk
	(diff-hunk-next))))))
1070

1071 1072 1073

(defun diff-test-hunk (&optional reverse)
  "See whether it's possible to apply the current hunk.
1074
With a prefix argument, try to REVERSE the hunk."
1075
  (interactive "P")
1076 1077
  (destructuring-bind (buf line-offset pos src dst &optional switched)
      (diff-find-source-location nil reverse)
1078
    (set-window-point (display-buffer buf) (+ pos (cdr src)))
1079
    (diff-hunk-status-msg line-offset (diff-xor reverse switched) t)))
1080

1081 1082 1083 1084

(defun diff-goto-source (&optional other-file)
  "Jump to the corresponding source line.
`diff-jump-to-old-file-flag' (or its opposite if the OTHER-FILE prefix arg
1085
is given) determines whether to jump to the old or the new file.
1086 1087 1088
If the prefix arg is bigger than 8 (for example with \\[universal-argument] \\[universal-argument])
  then `diff-jump-to-old-file-flag' is also set, for the next invocations."
  (interactive "P")
1089 1090 1091 1092 1093 1094 1095 1096
  ;; When pointing at a removal line, we probably want to jump to
  ;; the old location, and else to the new (i.e. as if reverting).
  ;; This is a convenient detail when using smerge-diff.
  (let ((rev (not (save-excursion (beginning-of-line) (looking-at "[-<]")))))
    (destructuring-bind (buf line-offset pos src dst &optional switched)
	(diff-find-source-location other-file rev)
      (pop-to-buffer buf)
      (goto-char (+ pos (cdr src)))
Miles Bader's avatar
Miles Bader committed
1097
      (diff-hunk-status-msg line-offset (diff-xor rev switched) t))))
1098

1099

1100
(defun diff-current-defun ()
1101 1102
  "Find the name of function at point.
For use in `add-log-current-defun-function'."
1103 1104 1105 1106 1107
  (destructuring-bind (buf line-offset pos src dst &optional switched)
      (diff-find-source-location)
    (save-excursion
      (beginning-of-line)
      (or (when (memq (char-after) '(?< ?-))
1108 1109 1110 1111
	    ;; Cursor is pointing at removed text.  This could be a removed
	    ;; function, in which case, going to the source buffer will
	    ;; not help since the function is now removed.  Instead,
	    ;; try to figure out the function name just from the code-fragment.
1112 1113 1114 1115 1116 1117 1118 1119 1120
	    (let ((old (if switched dst src)))
	      (with-temp-buffer
		(insert (car old))
		(goto-char (cdr old))
		(funcall (with-current-buffer buf major-mode))
		(add-log-current-defun))))
	  (with-current-buffer buf
	    (goto-char (+ pos (cdr src)))
	    (add-log-current-defun))))))
1121

1122 1123 1124
;; provide the package
(provide 'diff-mode)

1125
;;; Old Change Log from when diff-mode wasn't part of Emacs:
1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160
;; Revision 1.11  1999/10/09 23:38:29  monnier
;; (diff-mode-load-hook): dropped.
;; (auto-mode-alist): also catch *.diffs.
;; (diff-find-file-name, diff-mode):  add smarts to find the right file
;;     for *.rej files (that lack any file name indication).
;;
;; Revision 1.10  1999/09/30 15:32:11  monnier
;; added support for "\ No newline at end of file".
;;
;; Revision 1.9  1999/09/15 00:01:13  monnier
;; - added basic `compile' support.
;; - have diff-kill-hunk call diff-kill-file if it's the only hunk.
;; - diff-kill-file now tries to kill the leading garbage as well.
;;
;; Revision 1.8  1999/09/13 21:10:09  monnier
;; - don't use CL in the autoloaded code
;; - accept diffs using -T
;;
;; Revision 1.7  1999/09/05 20:53:03  monnier
;; interface to ediff-patch
;;
;; Revision 1.6  1999/09/01 20:55:13  monnier
;; (ediff=patch-file):  add bindings to call ediff-patch.
;; (diff-find-file-name):  taken out of diff-goto-source.
;; (diff-unified->context, diff-context->unified, diff-reverse-direction,
;;  diff-fixup-modifs):  only use the region if a prefix arg is given.
;;
;; Revision 1.5  1999/08/31 19:18:52  monnier
;; (diff-beginning-of-file, diff-prev-file):  fixed wrong parenthesis.
;;
;; Revision 1.4  1999/08/31 13:01:44  monnier
;; use `combine-after-change-calls' to minimize the slowdown of font-lock.
;;

;;; diff-mode.el ends here