[gtk+/wip/carlosg/event-delivery: 36/66] gtkwindow: Ignore implicit grabs going away if there is no focus

[Carlos Garnacho <carlosg src gnome org>]

commit 1c721f00d88805bc5bcfe695199a045c66995f9b
Author: Carlos Garnacho <carlosg gnome org>
Date:   Sat Apr 1 22:41:23 2017 +0200

    gtkwindow: Ignore implicit grabs going away if there is no focus
    
    There should be no circumstances where an implicit grab is requested but
    no focus exists, there's however circumstances (like windowing grabs taking
    input to a different window) where we might get implicit grabs being undone
    when then new window didn't create a focus for the pointer itself.

 gtk/gtkwindow.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/gtk/gtkwindow.c b/gtk/gtkwindow.c
index de5ba11..3841d1a 100644
--- a/gtk/gtkwindow.c
+++ b/gtk/gtkwindow.c
@@ -11592,6 +11592,8 @@ gtk_window_set_pointer_focus_grab (GtkWindow        *window,
   GtkPointerFocus *focus;
 
   focus = gtk_window_lookup_pointer_focus (window, device, sequence);
+  if (!focus && !grab_widget)
+    return;
   g_assert (focus != NULL);
   gtk_pointer_focus_set_implicit_grab (focus, grab_widget);
 }