add: if ( ! currency_name ) currency_name = ""; if ( ! currency_nickname ) currency_nickname = ""; if ( ! currency_iso_code ) currency_iso_code = "";
context: gboolean select_currency_in_iso_list ( GtkTreeSelection *selection, GtkTreeModel *model ){    gchar * currency_name, * currency_iso_code, * currency_nickname;    GtkWidget * entry_name, * entry_iso_code, * entry_code;    GtkTreeIter iter;    if (! gtk_tree_selection_get_selected (selection, NULL, &iter))	return(FALSE);    entry_name = g_object_get_data ( G_OBJECT(model), "entry_name" );    entry_iso_code = g_object_get_data ( G_OBJECT(model), "entry_iso_code" );    entry_code = g_object_get_data ( G_OBJECT(model), "entry_code" );    gtk_tree_model_get ( model, &iter, 			 CURRENCY_NAME_COLUMN, &currency_name,			 CURRENCY_ISO_CODE_COLUMN, &currency_iso_code,			 CURRENCY_NICKNAME_COLUMN, &currency_nickname, 			 -1 );    gtk_entry_set_text ( GTK_ENTRY ( entry_name ), currency_name );    gtk_entry_set_text ( GTK_ENTRY ( entry_iso_code ), currency_iso_code );    gtk_entry_set_text ( GTK_ENTRY ( entry_code ), currency_nickname );    return ( FALSE );} 