bug#55836: 29.0.50; (iconify-frame) freezes buffer view under Wayland.

[Po Lu]

"koaaa.outlook" <whainte@outlook.com> writes:

> * (iconify-frame) freezes buffer view under Wayland.  *
> This issue is not present under X11 sessions.
>
> Steps to reproduce:
> 1. Run 'emacs -Q' within a (e.g. KDE Plasma) Wayland session.
> 2. Input 'M-x iconify-frame C-m'.
> 3. Maximize emacs again.
>
> Expected Behavior: Buffer area keeps on updating itself.
>
> Observed Behavior: Buffer area freezes at the moment where
> 'C-m' is put in. The menu bar updates as normal.
> Emacs responds to user input without redrawing the buffer area.
>
> In GNU Emacs 29.0.50 (build 1, x86_64-pc-linux-gnu, GTK+ Version
> 3.24.34, cairo version 1.17.6)
> of 2022-06-06 built on soomakan
> Repository revision: dc9337aacd682b6346b7918ec9b3067e3a06269b
> Repository branch: master
> System Description: Arch Linux

I think this is a GTK bug, where the developers neglected to maintain
the iconification state on Wayland after GNOME removed the minimize
button from window title bars.

Can you set a breakpoint here (in pgtkterm.c), and see if it is ever hit
when you deiconify Emacs?

  if (event->window_state.new_window_state
      & GDK_WINDOW_STATE_ICONIFIED)
    SET_FRAME_ICONIFIED (f, true);
  else
    {
-->   FRAME_X_OUTPUT (f)->has_been_visible = true;
      inev.ie.kind = DEICONIFY_EVENT;
      XSETFRAME (inev.ie.frame_or_window, f);
      SET_FRAME_ICONIFIED (f, false);
    }