[Emacs-diffs] Changes to emacs/lisp/vc.el,v

[Eric S. Raymond]

CVSROOT:        /sources/emacs
Module name:    emacs
Changes by:     Eric S. Raymond <esr>   07/10/11 15:10:33

Index: vc.el
===================================================================
RCS file: /sources/emacs/emacs/lisp/vc.el,v
retrieving revision 1.465
retrieving revision 1.466
diff -u -b -r1.465 -r1.466
--- vc.el       10 Oct 2007 18:52:45 -0000      1.465
+++ vc.el       11 Oct 2007 15:10:32 -0000      1.466
@@ -1985,16 +1985,33 @@
       (error "Not a valid revision range."))
   (vc-diff-internal backend t files rev1 rev2 (interactive-p)))
 
+(defun vc-contains-version-controlled-file (dir)
+  "Return t if DIR contains a version-controlled file, nil otherwise."
+  (catch 'found
+    (mapc (lambda (f) (and (not (file-directory-p f)) (vc-backend f) (throw 
'found 't))) (directory-files dir))
+    nil))
+
 ;;;###autoload
 (defun vc-diff (historic)
   "Display diffs between file revisions.
-Normally this compares the current file and buffer with the most
-recent checked in revision of that file.  This uses no arguments.  With
-a prefix argument HISTORIC, it reads the file name to use and two
-revision designators specifying which revisions to compare."
+Normally this compares the currently selected fileset with their
+working revisions. With a prefix argument HISTORIC, it reads two revision
+designators specifying which revisions to compare.
+
+If no current fileset is available (that is, we are not in
+VC-Dired mode and the visited file of the current buffer is not
+under version control) behave specially; if there are
+version-controlled files in the current directory, treat all
+version-controlled files recursively beneath the current
+directory as the selected fileset.
+"
+
   (interactive "P")
-  (if historic
-      (call-interactively 'vc-history-diff)
+  (cond ((not (vc-contains-version-controlled-file default-directory))
+        (error "No version-controlled files directly beneath default 
directory"))
+       (historic
+        (call-interactively 'vc-history-diff))
+       (t
     (let* ((files (vc-deduce-fileset t))
           (first (car files))
           (backend 
@@ -2002,7 +2019,7 @@
                   (vc-responsible-backend first))
                  (t
                   (vc-backend first)))))
-      (vc-diff-internal backend t files nil nil (interactive-p)))))
+          (vc-diff-internal backend t files nil nil (interactive-p))))))
 
 ;;;###autoload
 (defun vc-revision-other-window (rev)