Re: find-file-literally and save-buffer

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

>> >> | emacs -Q
>> >> | M-x find-file-literally ~/RMAIL.empty RET
>> >> | C-u M-~   (not-modified t)
>> >> | C-x C-s   (save-buffer)
>> 
>> I think this might be related to me having my home directory under
>> version control ... I think it is because vc-arch-file-source-p
>> calls find-file-noselect, which in turn calls vc-arch-file-source-p,
>> and so on...

> Probably the fix is for vc-arch-file-source-p to check if
> get-file-buffer is nil; if so, it should perform insert-file-contents
> on a temp buffer, instead of visiting the file directly.

Sounds right,
I've just installed the patch below to address it,


        Stefan


--- vc-arch.el	29 jan 2007 13:35:19 -0500	1.23
+++ vc-arch.el	27 mar 2007 21:15:35 -0400	
@@ -109,6 +109,17 @@
 
 (defconst vc-arch-tagline-re "^\\W*arch-tag:[ \t]*\\(.*[^ \t\n]\\)")
 
+(defmacro vc-with-current-file-buffer (file &rest body)
+  (declare (indent 2) (debug t))
+  `(let ((-kill-buf- nil)
+         (-file- ,file))
+     (with-current-buffer (or (find-buffer-visiting -file-)
+                              (setq -kill-buf- (generate-new-buffer " temp")))
+       (if -kill-buf- (insert-file-contents -file-))
+       (unwind-protect
+           (progn ,@body)
+         (if -kill-buf- (kill-buffer -kill-buf-))))))
+
 (defun vc-arch-file-source-p (file)
   "Can return nil, `maybe' or a non-nil value.
 Only the value `maybe' can be trusted :-(."
@@ -122,7 +133,7 @@
 	  (concat ".arch-ids/" (file-name-nondirectory file) ".id")
 	  (file-name-directory file)))
 	;; Check the presence of a tagline.
-	(with-current-buffer (find-file-noselect file)
+	(vc-with-current-file-buffer file
 	  (save-excursion
 	    (goto-char (point-max))
 	    (or (re-search-backward vc-arch-tagline-re (- (point) 1000) t)