[dia] Database - Table: avoid crash on undo

[Hans Breuer <hans src gnome org>]

commit f58a009fe602df1e0edd5eeb23e4054c04c85f7d
Author: Hans Breuer <hans breuer org>
Date:   Mon Dec 28 19:21:27 2009 +0100

    Database - Table: avoid crash on undo

 objects/Database/table_dialog.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)
---
diff --git a/objects/Database/table_dialog.c b/objects/Database/table_dialog.c
index 2d25029..4d24f93 100644
--- a/objects/Database/table_dialog.c
+++ b/objects/Database/table_dialog.c
@@ -268,7 +268,8 @@ table_state_set (TableState * state, Table * table)
   table_compute_width_height (table);
   table_update_positions (table);
 
-  gtk_list_clear_items (table->prop_dialog->attributes_list, 0, -1);
+  if (table->prop_dialog)
+    gtk_list_clear_items (table->prop_dialog->attributes_list, 0, -1);
 }
 
 static void