(svn r26106) -Codechange: document fall through explicitly

src/depot_gui.cpp

@@ -442,6 +442,7 @@ struct DepotWindow : Window {
 			switch (this->type) {
 				case VEH_TRAIN:
 					if (wagon) return MODE_ERROR;
+					/* FALL THROUGH */
 				case VEH_ROAD:
 					if (xm <= this->flag_width) return MODE_START_STOP;
 					break;