--- a/src/depot_gui.cpp	Sun Nov 18 22:39:02 2007 +0000
+++ b/src/depot_gui.cpp	Sun Nov 18 23:13:53 2007 +0000
@@ -414,7 +414,7 @@
 	int mode = GetVehicleFromDepotWndPt(w, x, y, &v, &gdvp);
 
 	/* share / copy orders */
-	if (_thd.place_mode && mode <= 0) {
+	if (_thd.place_mode != VHM_NONE && mode <= 0) {
 		_place_clicked_vehicle = (WP(w, depot_d).type == VEH_TRAIN ? gdvp.head : v);
 		return;
 	}

--- a/src/viewport.cpp	Sun Nov 18 22:39:02 2007 +0000
+++ b/src/viewport.cpp	Sun Nov 18 23:13:53 2007 +0000
@@ -2270,6 +2270,10 @@
 					break;
 				case VHM_RAIL:
 					_thd.new_drawstyle = GetAutorailHT(pt.x, pt.y); // draw one highlighted tile
+					break;
+				default:
+					NOT_REACHED();
+					break;
 			}
 			_thd.new_pos.x = x1 & ~0xF;
 			_thd.new_pos.y = y1 & ~0xF;
@@ -2826,8 +2830,8 @@
 	Window *w;
 
 	/* undo clicking on button */
-	if (_thd.place_mode != 0) {
-		_thd.place_mode = 0;
+	if (_thd.place_mode != VHM_NONE) {
+		_thd.place_mode = VHM_NONE;
 		w = FindWindowById(_thd.window_class, _thd.window_number);
 		if (w != NULL) CallWindowEventNP(w, WE_ABORT_PLACE_OBJ);
 	}

--- a/src/viewport.h	Sun Nov 18 22:39:02 2007 +0000
+++ b/src/viewport.h	Sun Nov 18 23:13:53 2007 +0000
@@ -86,7 +86,7 @@
 	VPM_SIGNALDIRS      = 6, ///< similiar to VMP_RAILDIRS, but with different cursor
 };
 
-/* viewport highlight mode (for highlighting tiles below cursor) */
+/** Viewport highlight mode (for highlighting tiles below cursor) */
 enum ViewportHighlightMode {
 	VHM_NONE    = 0, ///< default
 	VHM_RECT    = 1, ///< rectangle (stations, depots, ...)
@@ -143,7 +143,7 @@
 	byte new_drawstyle;  // only used in UpdateTileSelection() to as a buffer to compare if there was a change between old and new
 	byte next_drawstyle; // queued, but not yet drawn style
 
-	byte place_mode;
+	ViewportHighlightMode place_mode;
 	bool make_square_red;
 	WindowClass window_class;
 	WindowNumber window_number;

--- a/src/window.cpp	Sun Nov 18 22:39:02 2007 +0000
+++ b/src/window.cpp	Sun Nov 18 23:13:53 2007 +0000
@@ -1772,7 +1772,7 @@
 			case MC_DOUBLE_LEFT:
 			case MC_LEFT:
 				DEBUG(misc, 2, "Cursor: 0x%X (%d)", _cursor.sprite, _cursor.sprite);
-				if (_thd.place_mode != 0 &&
+				if (_thd.place_mode != VHM_NONE &&
 						/* query button and place sign button work in pause mode */
 						_cursor.sprite != SPR_CURSOR_QUERY &&
 						_cursor.sprite != SPR_CURSOR_SIGN &&
@@ -1781,7 +1781,7 @@
 					return;
 				}
 
-				if (_thd.place_mode == 0) {
+				if (_thd.place_mode == VHM_NONE) {
 					HandleViewportClicked(vp, x, y);
 				} else {
 					PlaceObject();