bug#16430: 24.3.50; When fullscreen is triggered from the window manager, I can't resize window (via M-x org-export RET)

[martin rudalics]

> 2 windows of equal height.
>
>> Can you trigger it from
>> such a configuration by simply doing M-x fit-window-to-buffer RET?
>
> Yes, from last emacs -Q, even outside Org Export, you need two windows
> and M-x fit-window-to-buffer RET will fail sometimes.  But I can't
> provide a reproducible case for now.

This hints at the org buffer having some special character heights in
it.

> What happens is that, when `window--resizable-p' is called with the
> pixelwise parameter set to `t' (from within `window-resize'), then
> the delta (as pixel height) is too high

Can you tell me what delta is in both fullscreen versions?

> and `window--resizable-p'
> returns nil -- and window-resize an error.

Apparently `window-resize-no-error' calls `window--resizable-p' with
PIXELWISE nil yielding t while `window-resize' calls it with PIXELWISE t
yielding nil.  So rewriting `window-resize-no-error' as


(defun window-resize-no-error (window delta &optional horizontal ignore 
pixelwise)
  "Resize WINDOW vertically if it is resizable by DELTA lines.
This function is like `window-resize' but does not signal an
error when WINDOW cannot be resized.  For the meaning of the
optional arguments see the documentation of `window-resize'.

Optional argument PIXELWISE non-nil means interpret DELTA as
pixels."
  (unless pixelwise
    (setq delta
          (if horizontal
              (* delta (frame-char-width (window-frame window)))
            (* delta (frame-char-height (window-frame window))))))

  (when (window--resizable-p
         window delta horizontal ignore nil nil nil t)
    (window-resize window delta horizontal ignore t)))


should fix it.  Maybe I should just wrap this into a `condition-case'
instead of doing my own checking.

BTW what do (frame-pixel-height) and (frame-height) respectively give in
the two fullscreen versions?

martin