[libegg] EggSpreadTableDnd: Improve warnings.

[Murray Cumming <murrayc src gnome org>]

commit f52321b9b9fbccb0eb5d3141a7f2894d52883b0f
Author: Murray Cumming <murrayc murrayc com>
Date:   Thu Sep 1 12:08:55 2011 +0200

    EggSpreadTableDnd: Improve warnings.

 libegg/spreadtable/eggspreadtablednd.c |    7 ++++++-
 1 files changed, 6 insertions(+), 1 deletions(-)
---
diff --git a/libegg/spreadtable/eggspreadtablednd.c b/libegg/spreadtable/eggspreadtablednd.c
index 26e0a68..c7f7e38 100644
--- a/libegg/spreadtable/eggspreadtablednd.c
+++ b/libegg/spreadtable/eggspreadtablednd.c
@@ -1270,10 +1270,15 @@ egg_spread_table_dnd_remove_child (EggSpreadTableDnd *table,
   g_return_if_fail (GTK_IS_WIDGET (child));
 
   event_box = gtk_widget_get_parent (child);
+  if (!event_box)
+    {
+      g_message ("Bad hierarchy encountered in %s. The child had no parent.", G_STRFUNC);
+      return;
+    }
 
   if (GPOINTER_TO_INT (g_object_get_qdata (G_OBJECT (event_box), dnd_table_child_quark)) == FALSE)
     {
-      g_message ("Bad hierarchy encountered in egg_spread_table_dnd_remove_child().");
+      g_message ("Bad hierarchy encountered in %s.", G_STRFUNC);
       return;
     }