drawingarea: checks parent's draw() before call it

commit 6786c9d7 introduced a bug when a drawing area is used for
rendering videos, since GtkWidgetClass doesn't set a draw()
method by itself.

https://bugzilla.gnome.org/show_bug.cgi?id=751877

diff --git a/gtk/gtkdrawingarea.c b/gtk/gtkdrawingarea.c
index 94034059e10544a0d5259f7a993cc849df1d61cb..93b4b0a9bccfd151e3eb4012da831a90a27e9df0 100644 (file)
--- a/gtk/gtkdrawingarea.c
+++ b/gtk/gtkdrawingarea.c
@@ -219,7 +219,10 @@ gtk_drawing_area_draw (GtkWidget *widget,
                            gtk_widget_get_allocated_width (widget),
                            gtk_widget_get_allocated_height (widget));
 
-  return GTK_WIDGET_CLASS (gtk_drawing_area_parent_class)->draw (widget, cr);
+  if (GTK_WIDGET_CLASS (gtk_drawing_area_parent_class)->draw)
+    return GTK_WIDGET_CLASS (gtk_drawing_area_parent_class)->draw (widget, cr);
+
+  return FALSE;
 }
 
 static void