bug#6447: 23.1; revert-buffer in *vc-diff*

[Stefan Monnier <monnier@iro.umontreal.ca>]

>>>> Like the command `diff' after calling `diff-mode' sets
>>>> `revert-buffer-function' to lambda with its function arguments,
>>>> `vc-diff-internal' could do the same:
>>>> 
>>>> === modified file 'lisp/vc/vc.el'
>>>> --- lisp/vc/vc.el	2010-06-11 19:09:57 +0000
>>>> +++ lisp/vc/vc.el	2010-06-19 14:51:14 +0000
>>>> @@ -1547,6 +1547,9 @@ (defun vc-diff-internal (async vc-filese
>>>> (message "%s" (cdr messages))
>>>> nil)
>>>> (diff-mode)
>>>> +      (set (make-local-variable 'revert-buffer-function)
>>>> +	   `(lambda (ignore-auto noconfirm)
>>>> +	      (vc-diff-internal ,async ',vc-fileset ,rev1 ,rev2 ,verbose)))
>>>> ;; Make the *vc-diff* buffer read only, the diff-mode key
>>>> ;; bindings are nicer for read only buffers. pcl-cvs does the
>>>> ;; same thing.
>>> 
>>> Looks like a fine idea, please go ahead.
>> 
>> Done.

> It would be nice to also have revert-buffer bound to "g" in this case,
> that would make this feature easier to use (and consistent with what
> we do for other modes).

Fine by me (tho only when the diff-mode buffer is read-only, of course,
it would be rather awkward for editing otherwise).


        Stefan