[gtk+] box gadget: Improve assertion message

[Matthias Clasen <matthiasc src gnome org>]

commit 8991f17d49c757fbef2739d9d16a03e029daebda
Author: Matthias Clasen <mclasen redhat com>
Date:   Tue Jan 26 22:11:54 2016 -0500

    box gadget: Improve assertion message
    
    Include the owner of the gadget in the assertion message,
    to improve the chances of tracking down whats actually
    going wrong here.

 gtk/gtkboxgadget.c |    6 +++++-
 1 files changed, 5 insertions(+), 1 deletions(-)
---
diff --git a/gtk/gtkboxgadget.c b/gtk/gtkboxgadget.c
index ea18a21..1adbcb6 100644
--- a/gtk/gtkboxgadget.c
+++ b/gtk/gtkboxgadget.c
@@ -133,7 +133,11 @@ gtk_box_gadget_distribute (GtkBoxGadget     *gadget,
       size -= sizes[i].minimum_size;
     }
 
-  g_return_if_fail (size >= 0);
+  if G_UNLIKELY (size < 0)
+    {
+      g_critical ("%s: assertion 'size >= 0' failed in %s", G_STRFUNC, G_OBJECT_TYPE_NAME 
(gtk_css_gadget_get_owner (GTK_CSS_GADGET (gadget))));
+      return;
+    }
 
   size = gtk_distribute_natural_allocation (size, priv->children->len, sizes);