Don't bother making files writable for commit with modern VCS

* lisp/vc/vc.el (vc-next-action):
Only gripe about committing read-only files for RCS and SCCS.

Fixes: debbugs:9781

2 files changed, 26 insertions, 18 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 2bca85608be..7c803fcd2ea 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,8 @@
+2012-09-27  Glenn Morris  <rgm@gnu.org>
+
+        * vc/vc.el (vc-next-action): Only gripe about committing read-only
+        files for RCS and SCCS.  (Bug#9781)
+
 2012-09-27  Chong Yidong  <cyd@gnu.org>
 
         * progmodes/verilog-mode.el (verilog-mode-release-emacs): Fix last
diff --git a/lisp/vc/vc.el b/lisp/vc/vc.el
index 89e0d0c3ecd..2da721b41d8 100644
--- a/lisp/vc/vc.el
+++ b/lisp/vc/vc.el
@@ -1105,24 +1105,27 @@ For old-style locking-based version control systems, like RCS:
      ;; Files have local changes
      ((vc-compatible-state state 'edited)
       (let ((ready-for-commit files))
-        ;; If files are edited but read-only, give user a chance to correct.
-        (dolist (file files)
-          ;; If committing a mix of removed and edited files, the
-          ;; fileset has state = 'edited.  Rather than checking the
-          ;; state of each individual file in the fileset, it seems
-          ;; simplest to just check if the file exists.  Bug#9781.
-          (when (and (file-exists-p file) (not (file-writable-p file)))
-            ;; Make the file+buffer read-write.
-            (unless (y-or-n-p (format "%s is edited but read-only; make it writable and continue? " file))
-              (error "Aborted"))
-            ;; Maybe we somehow lost permissions on the directory.
-            (condition-case nil
-                (set-file-modes file (logior (file-modes file) 128))
-              (error (error "Unable to make file writable")))
-            (let ((visited (get-file-buffer file)))
-              (when visited
-                (with-current-buffer visited
-                  (read-only-mode -1))))))
+        ;; CVS, SVN and bzr don't care about read-only (bug#9781).
+        ;; RCS does, SCCS might (someone should check...).
+        (when (memq backend '(RCS SCCS))
+          ;; If files are edited but read-only, give user a chance to correct.
+          (dolist (file files)
+            ;; If committing a mix of removed and edited files, the
+            ;; fileset has state = 'edited.  Rather than checking the
+            ;; state of each individual file in the fileset, it seems
+            ;; simplest to just check if the file exists.        Bug#9781.
+            (when (and (file-exists-p file) (not (file-writable-p file)))
+              ;; Make the file+buffer read-write.
+              (unless (y-or-n-p (format "%s is edited but read-only; make it writable and continue? " file))
+                (error "Aborted"))
+              ;; Maybe we somehow lost permissions on the directory.
+              (condition-case nil
+                  (set-file-modes file (logior (file-modes file) 128))
+                (error (error "Unable to make file writable")))
+              (let ((visited (get-file-buffer file)))
+                (when visited
+                  (with-current-buffer visited
+                    (read-only-mode -1)))))))
         ;; Allow user to revert files with no changes
         (save-excursion
           (dolist (file files)