Bug 722996 - Cannot add stock price on Price Editor

gtk_combo_box_set_active() doesn't work if the model is changed after
the combo box is constructed.

src/gnome-utils/dialog-commodity.c

@@ -644,9 +644,8 @@ gnc_ui_update_namespace_picker (GtkWidget *cbwe,
 {
     GtkComboBox *combo_box;
     GtkTreeModel *model;
-    GtkTreeIter iter;
+    GtkTreeIter iter, match;
     GList *namespaces, *node;
-    gint current = 0, match = 0;
 
     g_return_if_fail(GTK_IS_COMBO_BOX (cbwe));
 
@@ -654,7 +653,8 @@ gnc_ui_update_namespace_picker (GtkWidget *cbwe,
     combo_box = GTK_COMBO_BOX(cbwe);
     model = gtk_combo_box_get_model(combo_box);
     gtk_list_store_clear(GTK_LIST_STORE(model));
-    gtk_combo_box_set_active(combo_box, -1);
+    gtk_tree_model_get_iter_first(model, &match);
+    gtk_combo_box_set_active_iter(combo_box, &match);
 
     /* fetch a list of the namespaces */
     switch (mode)
@@ -698,11 +698,10 @@ gnc_ui_update_namespace_picker (GtkWidget *cbwe,
         }
 
         if (init_string && (g_utf8_collate(node->data, init_string) == 0))
-            match = current;
-        current++;
+            match = iter;
     }
 
-    gtk_combo_box_set_active(combo_box, match);
+    gtk_combo_box_set_active_iter(combo_box, &match);
     g_list_free(namespaces);
 }