Show tracerestrict and/or progsig windows when ctrl-clicking signal.

src/rail_cmd.cpp

@@ -2939,6 +2939,32 @@ static TrackStatus GetTileTrackStatus_Track(TileIndex tile, TransportType mode,
 
 static bool ClickTile_Track(TileIndex tile)
 {
+	if (_ctrl_pressed && IsPlainRailTile(tile)) {
+		TrackBits trackbits = TrackStatusToTrackBits(GetTileTrackStatus(tile, TRANSPORT_RAIL, 0));
+
+		if (trackbits & TRACK_BIT_VERT) { // N-S direction
+			trackbits = (_tile_fract_coords.x <= _tile_fract_coords.y) ? TRACK_BIT_RIGHT : TRACK_BIT_LEFT;
+		}
+
+		if (trackbits & TRACK_BIT_HORZ) { // E-W direction
+			trackbits = (_tile_fract_coords.x + _tile_fract_coords.y <= 15) ? TRACK_BIT_UPPER : TRACK_BIT_LOWER;
+		}
+
+		Track track = FindFirstTrack(trackbits);
+		if (HasTrack(tile, track) && HasSignalOnTrack(tile, track)) {
+			bool result = false;
+			if (GetExistingTraceRestrictProgram(tile, track) != nullptr) {
+				ShowTraceRestrictProgramWindow(tile, track);
+				result = true;
+			}
+			if (IsPresignalProgrammable(tile, track)) {
+				ShowSignalProgramWindow(SignalReference(tile, track));
+				result = true;
+			}
+			return result;
+		}
+	}
+
 	if (!IsRailDepot(tile)) return false;
 
 	ShowDepotWindow(tile, VEH_TRAIN);

src/viewport.cpp

@@ -3290,6 +3290,9 @@ static bool CheckClickOnLandscape(const ViewPort *vp, int x, int y)
 {
 	Point pt = TranslateXYToTileCoord(vp, x, y);
 
+	_tile_fract_coords.x = pt.x & TILE_UNIT_MASK;
+	_tile_fract_coords.y = pt.y & TILE_UNIT_MASK;
+
 	if (pt.x != -1) return ClickTile(TileVirtXY(pt.x, pt.y));
 	return true;
 }