(diff-hunk-text): Properly handle one-sided context diffs.

(diff-apply-hunk): When done, advance to the next hunk.

2 files changed, 92 insertions, 72 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 608bdec8adb..7f3d49ba90d 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,16 @@
+2000-09-21  Stefan Monnier  <monnier@cs.yale.edu>
+
+        * diff-mode.el (diff-file-header-face): Reset to its previous value.
+        (diff-hunk-text): Correctly use offsets rather than buffer-positions.
+        (diff-xor): New function.
+        (diff-find-source-location): Use it.  Fix a stupid name clash.
+        (diff-hunk-status-msg): New function.
+        (diff-apply-hunk): Drop args OTHER-FILE, DRY-RUN, POPUP and NOERROR.
+        (diff-test-hunk): Use diff-find-source-location.
+        (diff-goto-source): Favor the `reverse'.
+        (diff-hunk-text): Properly handle one-sided context diffs.
+        (diff-apply-hunk): When done, advance to the next hunk.
+
 2000-09-21  Gerd Moellmann  <gerd@gnu.org>
 
         * add-log.el (change-log-date-face, change-log-name-face)
diff --git a/lisp/diff-mode.el b/lisp/diff-mode.el
index 17ef4697faf..1d00f696452 100644
--- a/lisp/diff-mode.el
+++ b/lisp/diff-mode.el
@@ -4,7 +4,7 @@
 
 ;; Author: Stefan Monnier <monnier@cs.yale.edu>
 ;; Keywords: patch diff
-;; Revision: $Id: diff-mode.el,v 1.20 2000/09/20 22:36:23 monnier Exp $
+;; Revision: $Id: diff-mode.el,v 1.21 2000/09/21 16:15:32 monnier Exp $
 
 ;; This file is part of GNU Emacs.
 
@@ -876,75 +876,80 @@ If CHAR-OFFSET is non-nil, it should be a char-offset in
 HUNK, and instead of a string, a cons cell is returned whose car is the
 appropriate text, and whose cdr is the corresponding char-offset in that text."
   (with-temp-buffer
-     (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) "")
-
-      (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))
-              (kill (or divider-pos (if destp src-pos dst-pos))))
-          (when (and kill (> kill keep))
-            (delete-region kill (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))))))
+    (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))))))
 
 
 (defun diff-find-text (text)
@@ -1010,7 +1015,7 @@ If TEXT isn't found, nil is returned."
 
 
 (defun diff-apply-hunk (&optional reverse)
-  "Apply the current hunk to the source file.
+  "Apply the current hunk to the source file and go to the next.
 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
@@ -1034,7 +1039,8 @@ hunk was applied backwards and nil if the hunk wasn't applied."
                    (if reverse
                        "Hunk hasn't been applied yet; apply it now? "
                      "Hunk has already been applied; undo it? ")))))
-      (message "(Nothing done)"))
+      (message "(Nothing done)")
+      nil)
      (t
       (let ((reversed (diff-xor switched reverse)))
         ;; Apply the hunk
@@ -1046,6 +1052,7 @@ hunk was applied backwards and nil if the hunk wasn't applied."
         (let ((win (display-buffer buf)))
           (set-window-point win (+ pos (cdr new))))
         (diff-hunk-status-msg line-offset reversed nil)
+        (diff-hunk-next)
         (if reversed 'reversed t))))))