[gtk/wip/baedert/transforms6: 28/31] compute_bounds: Add preconditions

[Timm Bäder <baedert src gnome org>]

commit a3c0d4cda8a35b4c6fbb44700fa5e5d367c4d9d8
Author: Timm Bäder <mail baedert org>
Date:   Sat Aug 18 14:47:08 2018 +0200

    compute_bounds: Add preconditions

 gtk/gtkwidget.c | 4 ++++
 1 file changed, 4 insertions(+)
---
diff --git a/gtk/gtkwidget.c b/gtk/gtkwidget.c
index 209f7b266b..4a57ca7ff1 100644
--- a/gtk/gtkwidget.c
+++ b/gtk/gtkwidget.c
@@ -11325,6 +11325,10 @@ gtk_widget_compute_bounds (GtkWidget       *widget,
   GtkCssStyle *style;
   GtkBorder margin, border, padding;
 
+  g_return_val_if_fail (GTK_IS_WIDGET (widget), FALSE);
+  g_return_val_if_fail (GTK_IS_WIDGET (target), FALSE);
+  g_return_val_if_fail (out_bounds != NULL, FALSE);
+
   ancestor = gtk_widget_common_ancestor (widget, target);
 
   if (!ancestor)