bug#3689: Problem with window-size-fixed

["Vincent Belaïche" <vincent.b.1@hotmail.fr>]

Dear EMACS experts,

A problem concerning window-size-fixed was reported on
newsgroupfr.comp.applications.emacs
(http://groups.google.fr/group/fr.comp.applications.emacs/browse_thread/thread/f617026a5906fcd3#)

To see the problem put the following code into a file test.el and launch
emacs with: emacs -q -l test.el

;----------------------------------------------
(setq inhibit-startup-message t) 
(split-window-vertically) 
(split-window-vertically) 
(split-window-horizontally) 
(switch-to-buffer (get-buffer-create "buffer1")) 
(select-window (next-window)) 
(switch-to-buffer (get-buffer-create "buffer2")) 
(select-window (next-window)) 
(switch-to-buffer (get-buffer-create "buffer3")) 
(select-window (next-window)) 
(switch-to-buffer (get-buffer-create "buffer4")) 
(select-window (previous-window)) 
(enlarge-window (- 5 (window-height))) 
(setq window-size-fixed t)
;----------------------------------------------

I have tested this with the very latest CVS version GNU Emacs 23.1.50.1
(i386-mingw-nt5.0.2195) of 2009-07-25 and the same problem happens.

So what happens is that I correctly get the following window
partitionning:

Buffer 1 | Buffer 2 
---------+--------- 
  Buffer 3 
------------------- 
  Buffer 4 
------------------- 

with buf 1 and 2 of 7 rows, buf 3 of 4 rows, and buf 4 taking the
remainder (that is 38 rows for me).  The issue is that buffer 3 is
supposed to be fixed-size. This is true if you use `C-u N C-x ^' for
re-dimensionning, but it is not true if you try to do it by mouse, in
that case buffer 4 is fixed-size instead.

Best regards,
    Vincent.