fix-42655 3c4edfd: Prevent from frozen frame after `C-z' in Lucid builds

[Tino Calancha]

branch: fix-42655
commit 3c4edfd85ee8f49e40715a400a1fc65950e07482
Author: Tino Calancha <tino.calancha@gmail.com>
Commit: Tino Calancha <tino.calancha@gmail.com>

    Prevent from frozen frame after `C-z' in Lucid builds
    
    Some WMs (e.g. mutter in Gnome Shell) don't unmap iconized windows,
    thus we won't get a MapNotify when deconifying them.
    Check if we are deconifying a window elsewhere (Bug#42655).
    
    - src/xterm.c (handle_one_xevent):
    Check for window deconify when receiving a FocusIn signal.
---
 src/xterm.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/src/xterm.c b/src/xterm.c
index 4439695..a567ab1 100644
--- a/src/xterm.c
+++ b/src/xterm.c
@@ -8762,6 +8762,20 @@ handle_one_xevent (struct x_display_info *dpyinfo,
       goto OTHER;
 
     case FocusIn:
+      /* Some WMs (e.g. Mutter in Gnome Shell), don't unmap
+         minimized/iconified windows; thus, for those WMs we won't get
+         a MapNotify when unminimizing/deconifying.  Check here if we
+         are deconizing a window (Bug42655). */
+      f = any;
+      if (f && FRAME_ICONIFIED_P (f))
+       {
+          SET_FRAME_VISIBLE (f, 1);
+          SET_FRAME_ICONIFIED (f, false);
+          f->output_data.x->has_been_visible = true;
+          inev.ie.kind = DEICONIFY_EVENT;
+          XSETFRAME (inev.ie.frame_or_window, f);
+        }
+
       x_detect_focus_change (dpyinfo, any, event, &inev.ie);
       goto OTHER;