[gtk/fix-gen-demo-conf: 4/5] gtkwindow: Fix "shadowed" checks for GTK grabs

[Chun-wei Fan <fanchunwei src gnome org>]

commit 1e18aad656d1ab9fd4f4ad978f5024be710c00c6
Author: Carlos Garnacho <carlosg gnome org>
Date:   Mon May 17 23:57:17 2021 +0200

    gtkwindow: Fix "shadowed" checks for GTK grabs
    
    We iterate here from the target widget up the toplevel checking
    for the previous and new grab, there's however 2 bugs here:
    - The check for is_shadowed was different to the check for was_shadowed
    - The loop started with the assumption that the widgets did not hold
      a grab, just to change it if the grab widget was found. (or maybe
      it's the other way around? it's unclear with the differing checks
      for past/present state).
    
    Make these checks consistent, and ensure we start with the right
    assumption for the past/present grabbing state, and accounting that
    new/old grab widgets may or may not be part of the pick stack.

 gtk/gtkwindow.c | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)
---
diff --git a/gtk/gtkwindow.c b/gtk/gtkwindow.c
index 33e1379a25..5d6ba32897 100644
--- a/gtk/gtkwindow.c
+++ b/gtk/gtkwindow.c
@@ -6748,6 +6748,10 @@ gtk_window_propagate_grab_notify (GtkWindow *window,
 
   while (target)
     {
+      if (target == old_grab_widget)
+        was_grabbed = TRUE;
+      if (target == new_grab_widget)
+        is_grabbed = TRUE;
       widgets = g_list_prepend (widgets, g_object_ref (target));
       target = gtk_widget_get_parent (target);
     }
@@ -6758,11 +6762,13 @@ gtk_window_propagate_grab_notify (GtkWindow *window,
     {
       gboolean was_shadowed, is_shadowed;
 
-      was_grabbed |= (l->data == old_grab_widget);
-      is_grabbed |= (l->data == new_grab_widget);
-
       was_shadowed = old_grab_widget && !was_grabbed;
-      is_shadowed = new_grab_widget && is_grabbed;
+      is_shadowed = new_grab_widget && !is_grabbed;
+
+      if (l->data == old_grab_widget)
+        was_grabbed = FALSE;
+      if (l->data == new_grab_widget)
+        is_grabbed = FALSE;
 
       if (was_shadowed == is_shadowed)
         break;