Handle git-style backup names in file-name-version-regexp (Bug#8159).

* files.el (file-name-version-regexp): Handle backup files of the
form `foo.js.~HEAD~1~' (Bug#8159).

lisp/ChangeLog

+2011-03-05  Reuben Thomas  <rrt@sc3d.org>
+
+	* files.el (file-name-version-regexp): Handle backup files of the
+	form `foo.js.~HEAD~1~' (Bug#8159).
+
 2011-03-05  Glenn Morris  <rgm@gnu.org>
 	* eshell/esh-var.el: Don't require esh-test when compiling.

lisp/files.el

@@ -3869,7 +3869,9 @@ BACKUPNAME is the backup file name, which is the old file renamed."
        (set-file-selinux-context to-name context)))
 
 (defvar file-name-version-regexp
-  "\\(?:~\\|\\.~[-[:alnum:]:#@^._]+~\\)"
+  "\\(?:~\\|\\.~[-[:alnum:]:#@^._]+\\(?:~[[:digit:]]+\\)?~\\)"
+  ;; The last ~[[:digit]]+ matches relative versions in git,
+  ;; e.g. `foo.js.~HEAD~1~'.
   "Regular expression matching the backup/version part of a file name.
 Used by `file-name-sans-versions'.")