[gtk: 1/2] gtkimcontextxim: fix gtk_im_context_xim_set_client_widget not handling widget=NULL

[Benjamin Otte <otte src gnome org>]

commit 8c2c748c1171009f8a063aec2fe1f2d193be682c
Author: Christoph Reiter <creiter src gnome org>
Date:   Sun Mar 4 18:40:12 2018 +0100

    gtkimcontextxim: fix gtk_im_context_xim_set_client_widget not handling widget=NULL
    
    gtk_im_context_set_client_widget() allows passing NULL as widget to signal that
    the widget no longer exists. The xim implementation didn't handle that
    case which led to the test suite on gitlab-ci failing.

 gtk/gtkimcontextxim.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)
---
diff --git a/gtk/gtkimcontextxim.c b/gtk/gtkimcontextxim.c
index 15e3cce131..8c84c54146 100644
--- a/gtk/gtkimcontextxim.c
+++ b/gtk/gtkimcontextxim.c
@@ -575,9 +575,12 @@ gtk_im_context_xim_set_client_widget (GtkIMContext *context,
                                       GtkWidget    *widget)
 {
   GtkIMContextXIM *context_xim = GTK_IM_CONTEXT_XIM (context);
-  GtkWidget *toplevel = gtk_widget_get_toplevel (widget);
+  GdkWindow *window = NULL;
 
-  set_ic_client_window (context_xim, gtk_widget_get_window (toplevel));
+  if (widget != NULL)
+    window = gtk_widget_get_window (gtk_widget_get_toplevel (widget));
+
+  set_ic_client_window (context_xim, window);
 }
 
 GtkIMContext *