[libgda] Test for signal ID's validity before disconnecting it

[Vivien Malerba <vivien src gnome org>]

commit 3272bfd7191c2a177d9081300bc72a58c95da758
Author: Vivien Malerba <malerba gnome-db org>
Date:   Fri Sep 4 21:53:02 2009 +0200

    Test for signal ID's validity before disconnecting it

 libgda-ui/gdaui-basic-form.c |    6 ++++--
 1 files changed, 4 insertions(+), 2 deletions(-)
---
diff --git a/libgda-ui/gdaui-basic-form.c b/libgda-ui/gdaui-basic-form.c
index b421b67..d63703c 100644
--- a/libgda-ui/gdaui-basic-form.c
+++ b/libgda-ui/gdaui-basic-form.c
@@ -1371,8 +1371,10 @@ gdaui_basic_form_clean (GdauiBasicForm *form)
 	if (form->priv->set) {
 		for (i = 0, list = form->priv->set->holders; 
 		     list; 
-		     i++, list = list->next)
-			g_signal_handler_disconnect (G_OBJECT (list->data), form->priv->signal_ids[i]);
+		     i++, list = list->next) {
+			if (form->priv->signal_ids[i] > 0)
+				g_signal_handler_disconnect (G_OBJECT (list->data), form->priv->signal_ids[i]);
+		}
 		g_free (form->priv->signal_ids);
 		form->priv->signal_ids = NULL;
 	}