widget: Make sure we're not calling _get_parent on NULL

We already issue the first _get_parent call before even entering that
loop, so make sure `parent` is not NULL. This happens when event_widget
is already a toplevel, and this change fixes row-dragging in treeviews.

diff --git a/gtk/gtkwidget.c b/gtk/gtkwidget.c
index 17158c289bfda5446c891a56b8691316957cdd66..bdffa04ad97de2967827c0bc0c2c39b2d83fe056 100644 (file)
--- a/gtk/gtkwidget.c
+++ b/gtk/gtkwidget.c
@@ -3585,7 +3585,7 @@ _gtk_widget_emulate_press (GtkWidget      *widget,
   next_child = event_widget;
   parent = _gtk_widget_get_parent (next_child);
 
-  while (parent != widget)
+  while (parent && parent != widget)
     {
       next_child = parent;
       parent = _gtk_widget_get_parent (parent);