[gtk+] inspector: Avoid a crash

[Matthias Clasen <matthiasc src gnome org>]

commit 6f1c945010480c0f459ee7d334d9688829bc8b69
Author: Matthias Clasen <mclasen redhat com>
Date:   Sun Dec 6 17:25:31 2015 -0500

    inspector: Avoid a crash
    
    gkt_cell_layout_get_area may return NULL, handle it.

 gtk/inspector/object-tree.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/gtk/inspector/object-tree.c b/gtk/inspector/object-tree.c
index ad54f40..8806e9a 100644
--- a/gtk/inspector/object-tree.c
+++ b/gtk/inspector/object-tree.c
@@ -332,6 +332,9 @@ object_tree_cell_layout_forall (GObject              *object,
     return;
 
   area = gtk_cell_layout_get_area (GTK_CELL_LAYOUT (object));
+  if (!area)
+    return;
+
   g_object_set_data (G_OBJECT (area), "gtk-inspector-cell-layout", object);
   forall_func (G_OBJECT (area), "cell-area", forall_data);
 }