bug#21100: 25.0.50; quit-restore-window should also retore width, not just height

[martin rudalics <rudalics@gmx.at>]

 > 1. Split the frame into two windows, one above the other.
 > 2. Make the bottom window very small.
 > 3. With point in the larger window, run `C-h f point RET'
 > 4. The bottom window increases in size to display the Help buffer.

I can't reproduce that here.  Even with `temp-buffer-resize-mode'
enabled, the window doen't change its size because reused windows are
not resized.  From the doc-string of `temp-buffer-resize-mode':

   When Temp Buffer Resize mode is enabled, the windows in which we
   show a temporary buffer are automatically resized in height to
   fit the buffer's contents, but never more than
   `temp-buffer-max-height' nor less than `window-min-height'.

   A window is resized only if it has been specially created for the
   buffer.  Windows that have shown another buffer before are not
   resized.  A frame is resized only if `fit-frame-to-buffer' is
   non-nil.

So what did you do to accomplish that resize?

 > 5. Hit q in the help buffer.
 > 6. The height of the bottom window is retored.

Here the size remains unchanged again.

 > This does not happen if you split the frame into side-by-side windows,
 > and make of them very narrow. In this case, the width of the window
 > increases to display the help buffer,

For such behavior your `fit-window-to-buffer-horizontally' must be
non-nil, I presume.

 > but it is not restored on quit.

It's true that `quit-restore-window' can't restore a previous width and
it should be fairly easy to fix that.  But can you provide me a simple
scenario starting with emacs -Q so I can test it?  I apparently forgot
how this is supposed to work.

martin