[gtk/gtk-3-24] [quartz] find_toplevel_under_pointer should not return _gdk_root

[John Ralls <jralls src gnome org>]

commit 7a56fa276b2bfc074191f4470a1426cba2a8dcfb
Author: John Ralls <jralls ceridwen us>
Date:   Fri Jul 22 10:54:27 2022 -0700

    [quartz] find_toplevel_under_pointer should not return _gdk_root
    
    The macOS WM has no root window. We fake one with a 1x1 window at the
    origin that has no associated NSWindow. If the pointer is not on a
    realized GdkWindow the hierarchical search will place it in the root
    window even if it's nowhere near it. That's not valid, but returning it
    from find_toplevel_under_pointer prevents Gdk from discovering when the
    pointer is really over a GdkWindow. Return NULL instead so that the window
    discovery is re-performed.

 gdk/quartz/gdkevents-quartz.c | 12 ++++--------
 1 file changed, 4 insertions(+), 8 deletions(-)
---
diff --git a/gdk/quartz/gdkevents-quartz.c b/gdk/quartz/gdkevents-quartz.c
index 3cfc93e19d..f94fd978a0 100644
--- a/gdk/quartz/gdkevents-quartz.c
+++ b/gdk/quartz/gdkevents-quartz.c
@@ -659,15 +659,11 @@ find_toplevel_under_pointer (GdkDisplay *display,
 
     }
 
-  if (toplevel == NULL)
-    return NULL;
-
-  /*
-   * Root window type does not need translation, but also does not have
-   * an associated NSWindow and therefore can't translate screen points
+  /* If the stored toplevel is NULL or _gdk_root it's not useful,
+   * return NULL to regenerate.
    */
-  if (toplevel == _gdk_root)
-    return toplevel;
+  if (toplevel == NULL || toplevel == _gdk_root )
+    return NULL;
 
   get_window_point_from_screen_point (toplevel, screen_point, x, y);
   /* If the coordinates are out of window bounds, this toplevel is not