Test fox for memory leak

source/ubl-settings-usergroups.c

@@ -2288,7 +2288,7 @@ void on_parameter_changed(GtkWidget *self,ubl_settings_usergroups_user_window *w
 	!yon_char_is_empty(do_not_check)?" ":"",
 	yon_char_return_if_exist(no_user_group,""),
 	NULL);
-	if (strlen(final_string)){
+	if (final_string&&strlen(final_string)){
 		if (final_string[strlen(final_string)-1]==' ') final_string[strlen(final_string)-1]='\0';
 		gtk_entry_set_text(GTK_ENTRY(window->userExtraOptionsEntry),final_string);
 		free(final_string);