bug#46827: Broken initial size of GTK3 frame

[martin rudalics]

>> In either case, the more I look into this, the more things confuse me.
>> For example, why does
>>
>>          if (!must_finish)
>>            {
>>              do_pending_window_change (true);
>>              /* If selected_window changed, redisplay again.  */
>>              if (WINDOWP (selected_window)
>>                  && (w = XWINDOW (selected_window)) != sw)
>>                goto retry;
>>
>> not check for windows_or_buffers_changed too just as we do after the
>> third do_pending_window_change call?
>
> Because going to 'retry' will eventually make that check again.  Or
> maybe I don't understand what exactly are you asking here?

The check above doesn't care about windows_or_buffers_changed.  The last
one in redisplay_internal does:

  /* Change frame size now if a change is pending.  */
  do_pending_window_change (true);

  /* If we just did a pending size change, or have additional
     visible frames, or selected_window changed, redisplay again.  */
  if ((windows_or_buffers_changed && !pending)
      || (WINDOWP (selected_window)
          && (w = XWINDOW (selected_window)) != sw))
    goto retry;

So if in the (!must_finish) guarded check windows_or_buffers_changed was
set but the selected window remained unchanged, we don't go to retry.

>> But then I don't understand why we
>> check for windows_or_buffers_changed at all.  adjust_frame_size doesn't
>> set that IIUC but it does garbage the frame - why don't we check that in
>> redisplay_internal?
>
> Sorry, I don't understand the question.  We _are_ talking about
> redisplay_internal, right? and redisplay_internal does check
> windows_or_buffers_changed, right? so what do you mean by "why don't
> we check that in redisplay_internal"? and what is "that" in this case?

I meant to ask why we don't check the f->garbaged flag of the frame
instead of windows_or_buffers_changed.  do_pending_window_change to my
knowledge does not set windows_or_buffers_changed but sets the garbaged
flag.

>> Never-ever.  Fdelete_window_internal, Fdelete_other_windows_internal and
>> Fset_window_configuration are the only functions allowed to delete
>> windows.
>
> Not even due to some Lisp hook run directly or indirectly when the
> frame is resized?

run_window_scroll_functions could do it later on, but that is run by
redisplay itself.

> If this can never happen, we should replace the test with an
> assertion, and wait for it to fire if we are missing something.

I'll try that here.

martin