(hs-hide-block): Fix message spelling.

[bpt/emacs.git] / lisp / diff.el

diff --git a/lisp/diff.el b/lisp/diff.el
index c4a8311..eb2e415 100644 (file)
--- a/lisp/diff.el
+++ b/lisp/diff.el
@@ -1,6 +1,6 @@
 ;;; diff.el --- Run `diff' in compilation-mode.
 
-;; Copyright (C) 1992 Free Software Foundation, Inc.
+;; Copyright (C) 1992, 1994 Free Software Foundation, Inc.
 
 ;; Keywords: unix, tools
 
@@ -30,9 +30,13 @@
 
 (require 'compile)
 
+;;; This is duplicated in vc.el.
 (defvar diff-switches "-c"
   "*A string or list of strings specifying switches to be be passed to diff.")
 
+(defvar diff-command "diff"
+  "*The command to use to run diff.")
+
 (defvar diff-regexp-alist
   '(
     ;; -u format: @@ -OLDSTART,OLDEND +NEWSTART,NEWEND @@
@@ -112,7 +116,8 @@ is nil, REGEXP matches only half a section.")
                                                (match-beginning subexpr)
                                                (match-end subexpr)))))
                                    (save-excursion
-                                     (set-buffer (find-file-noselect file))
+                                     (save-match-data
+                                       (set-buffer (find-file-noselect file)))
                                      (save-excursion
                                        (goto-line line)
                                        (point-marker)))))
@@ -157,7 +162,7 @@ is nil, REGEXP matches only half a section.")
 ;;;###autoload
 (defun diff (old new &optional switches)
   "Find and display the differences between OLD and NEW files.
-Interactively the current buffer's file name is the default for for NEW
+Interactively the current buffer's file name is the default for NEW
 and a backup file for NEW is the default for OLD.
 With prefix arg, prompt for diff switches."
   (interactive
@@ -194,31 +199,37 @@ With prefix arg, prompt for diff switches."
     (unwind-protect
        (let ((command
               (mapconcat 'identity
-                         (append '("diff")
-                                 (if (consp diff-switches)
-                                     diff-switches
-                                   (list diff-switches))
+                         (append (list diff-command)
+                                 ;; Use explicitly specified switches
+                                 (if switches
+                                     (if (consp switches)
+                                         switches (list switches))
+                                   ;; If not specified, use default.
+                                   (if (consp diff-switches)
+                                       diff-switches
+                                     (list diff-switches)))
                                  (if (or old-alt new-alt)
                                      (list "-L" old "-L" new))
-                                 (list (or old-alt old))
-                                 (list (or new-alt new)))
+                                 (list
+                                  (shell-quote-argument (or old-alt old)))
+                                 (list
+                                  (shell-quote-argument (or new-alt new))))
                          " ")))
          (setq buf
                (compile-internal command
                                  "No more differences" "Diff"
                                  'diff-parse-differences))
-         (save-excursion
-           (set-buffer buf)
-           (set (make-local-variable 'diff-old-file) old)
-           (set (make-local-variable 'diff-new-file) new)
-           (set (make-local-variable 'diff-old-temp-file) old-alt)
-           (set (make-local-variable 'diff-new-temp-file) new-alt)
-           (set (make-local-variable 'compilation-finish-function)
-                (function (lambda (buff msg)
-                            (if diff-old-temp-file
-                                (delete-file diff-old-temp-file))
-                            (if diff-new-temp-file
-                                (delete-file diff-new-temp-file))))))
+         (pop-to-buffer buf)
+         (set (make-local-variable 'diff-old-file) old)
+         (set (make-local-variable 'diff-new-file) new)
+         (set (make-local-variable 'diff-old-temp-file) old-alt)
+         (set (make-local-variable 'diff-new-temp-file) new-alt)
+         (set (make-local-variable 'compilation-finish-function)
+              (function (lambda (buff msg)
+                          (if diff-old-temp-file
+                              (delete-file diff-old-temp-file))
+                          (if diff-new-temp-file
+                              (delete-file diff-new-temp-file)))))
          buf))))
 
 ;;;###autoload
@@ -246,26 +257,33 @@ The backup file is the first file given to `diff'."
 
 (defun diff-latest-backup-file (fn)    ; actually belongs into files.el
   "Return the latest existing backup of FILE, or nil."
-  ;; First try simple backup, then the highest numbered of the
-  ;; numbered backups.
-  ;; Ignore the value of version-control because we look for existing
-  ;; backups, which maybe were made earlier or by another user with
-  ;; a different value of version-control.
-  (setq fn (expand-file-name fn))
-  (or
-   (let ((bak (make-backup-file-name fn)))
-     (if (file-exists-p bak) bak))
-   (let* ((dir (file-name-directory fn))
-         (base-versions (concat (file-name-nondirectory fn) ".~"))
-         (bv-length (length base-versions)))
-     (concat dir
-            (car (sort
-                  (file-name-all-completions base-versions dir)
-                  ;; bv-length is a fluid var for backup-extract-version:
-                  (function
-                   (lambda (fn1 fn2)
-                     (> (backup-extract-version fn1)
-                        (backup-extract-version fn2))))))))))
+  (let ((handler (find-file-name-handler fn 'diff-latest-backup-file)))
+    (if handler
+       (funcall handler 'diff-latest-backup-file fn)
+      ;; First try simple backup, then the highest numbered of the
+      ;; numbered backups.
+      ;; Ignore the value of version-control because we look for existing
+      ;; backups, which maybe were made earlier or by another user with
+      ;; a different value of version-control.
+      (setq fn (file-chase-links (expand-file-name fn)))
+      (or
+       (let ((bak (make-backup-file-name fn)))
+        (if (file-exists-p bak) bak))
+       ;; We use BACKUPNAME to cope with backups stored in a different dir.
+       (let* ((backupname (car (find-backup-file-name fn)))
+             (dir (file-name-directory backupname))
+             (base-versions (concat (file-name-sans-versions
+                                     (file-name-nondirectory backupname))
+                                    ".~"))
+             (bv-length (length base-versions)))
+        (concat dir
+                (car (sort
+                      (file-name-all-completions base-versions dir)
+                      ;; bv-length is a fluid var for backup-extract-version:
+                      (function
+                       (lambda (fn1 fn2)
+                         (> (backup-extract-version fn1)
+                            (backup-extract-version fn2))))))))))))
 
 (provide 'diff)