[gtk+] widget: Always assign values to out parameter in translate_coordinates

[Timm Bäder <baedert src gnome org>]

commit aee4634ee52220291a898318a7b3e22ec3fcbed2
Author: Timm Bäder <mail baedert org>
Date:   Thu Jan 18 14:43:36 2018 +0100

    widget: Always assign values to out parameter in translate_coordinates
    
    safe guard against people using the returned coordinate values without
    checking the return value of gtk_widget_translate_coordinates.

 gtk/gtkwidget.c |    8 +++++++-
 1 files changed, 7 insertions(+), 1 deletions(-)
---
diff --git a/gtk/gtkwidget.c b/gtk/gtkwidget.c
index 46ad980..55c4d60 100644
--- a/gtk/gtkwidget.c
+++ b/gtk/gtkwidget.c
@@ -4888,7 +4888,13 @@ gtk_widget_translate_coordinates (GtkWidget  *src_widget,
 
   ancestor = gtk_widget_common_ancestor (src_widget, dest_widget);
   if (!ancestor || !_gtk_widget_get_realized (src_widget) || !_gtk_widget_get_realized (dest_widget))
-    return FALSE;
+    {
+      if (dest_x)
+        *dest_x = 0;
+      if (dest_y)
+        *dest_y = 0;
+      return FALSE;
+    }
 
 
   parent = src_widget;