bug#12419: Mouse click changes layout

[Eli Zaretskii <eliz@gnu.org>]

> Date: Sat, 15 Sep 2012 12:39:29 +0200
> From: martin rudalics <rudalics@gmx.at>
> CC: occitan@esperanto.org, 12419@debbugs.gnu.org
> 
>  >> You see no problem with minibuffer window resizing not restoring the
>  >> initial configuration?
>  >
>  > When the minibuffer window's growth absolutely must resize windows
>  > other than the lowest one, no.  IMO, it's better than Emacs 23's
>  > punting and displaying only a portion of the echo-area message.
> 
> Where do you see that?  Can you give an example?

Try the recipe I showed earlier in this thread with Emacs 23.3, but
use 1000 instead of 380, and you will see that only the last part of
the echo-area message is shown.

>  >>  >> I use ediff with the control panel on the bottom of the frame.  How can
>  >>  >> I resize the minibuffer in this case?
>  >>  >
>  >>  > Why, by resizing the window above the control panel, of course.
>  >>
>  >> And how would you size the minibuffer back?
>  >
>  > I don't understand the problem you obviously have in mind.
> 
> Then put a one-line window at the bottom of your frame and resize the
> minibuffer.  At the time it sizes back the one-line window has grown.

OK, but why is that a problem grave enough to be concerned about?
Using Ediff in such a way is non-standard, so won't be a problem for
most users.  And even in this configuration, what is so bad about
this?

>  > If the lowest window is large enough, why not show more of
>  > the echo-area message, instead of always showing only the last N lines?
> 
> I don't understand you.  As far as minibuffer resizing is concerned, you
> can show any number of lines in the minibuffer as long as you don't try
> to delete other windows.  So the N lines restriction you see must come
> from somewhere else.

Maybe it does, but I tried that with "emacs -Q", so the number of such
other places is severely limited ;-)

AFAICS, with your patch the minibuffer is never resized to show more
than 9 lines, with the default size of the frame which can show 33
text lines.  This is so even if I do _not_ split the frame into 2
windows, one below the other, but instead invoke 'message' from the
original window configuration displayed by "emacs -Q", where there's a
single window showing the "*scratch*" buffer.  Try this:

  emacs -Q
  (message (make-string 1000 ?a))
  C-x C-e

How many lines and how many a's do you see in the echo area?