bug#7221: timestamp in cvs-quickdir on Win32 system

[Lars Ingebrigtsen <larsi@gnus.org>]

(I'm going through old bug reports that unfortunately got no attention
at the time.)

Rolf Unger <rz.unger@web.de> writes:

> I realized that the cvs-quickdir command always returned MODIFIED for the
> state of the files under CVS when running this on MS Win2k. At some time
> I was using cvs-quickdir on a Linux box and was suprised that the results
> were correct on Linux.
>
> I inspected this a bit closer and figured out that the problem is in the
> pcvs-info.el:cvs-fileinfo-from-entries function. Comparing the file
> attributes time with the timestamp from the CVS/Entries file seems to
> compare two different formats.
>
>  (setq timestamp (format-time-string "%c" mtime 'utc))
>
> seems to be the problem. I experimented a bit with the format-time-string
> and found out that the "%c" format specifier is not robust on Win32
>
>  (insert (concat "\n" (format-time-string "%c" (current-time) t)))
>
> gives me after:
>
>  (setq system-time-locale nil):  15.10.2010 10:45:44
>
>  (setq system-time-locale "C"):  10/15/10 10:44:52
>
> The first one picks up my locale settings from the OS and is the common
> german format. But only the second one is relevant for cvs-quickdir.
>
> If I use a detailed format string "%a %b %e %H:%M:%S %Y" I get the date
> string in a format that matches what is used in CVS/Entries.

So the suggestion is to do this:

diff --git a/lisp/vc/pcvs-info.el b/lisp/vc/pcvs-info.el
index 9f8a168a0a..5a607e337b 100644
--- a/lisp/vc/pcvs-info.el
+++ b/lisp/vc/pcvs-info.el
@@ -454,7 +454,8 @@ cvs-fileinfo-from-entries
 	       ((let ((mtime (file-attribute-modification-time
 			      (file-attributes (concat dir f))))
 		      (system-time-locale "C"))
-		  (setq timestamp (format-time-string "%c" mtime t))
+		  (setq timestamp (format-time-string "%a %b %e %H:%M:%S %Y"
+                                                      mtime t))
 		  ;; Solaris sometimes uses "Wed Sep 05", not "Wed Sep  5".
 		  ;; See "grep '[^a-z_]ctime' cvs/src/*.c" for reference.
 		  (if (= (aref timestamp 8) ?0)

But I guess the assumption here is that cvs will output the date in the
locale's date format, which is why we're using %c here.  If your cvs
outputs in ISO8601 no matter what your locale is, then you'll get a
mismatch here.

So I'm kinda leaning towards this not being a bug, but a cvs version
that doesn't behave correctly...

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no