fix: go to house with no exit (#92)

Now when you double click a house with no exit, it will take you to the first valid tile.
Makes easier to fix the warning about houses with no exit.

source/house.h

@@ -53,6 +53,10 @@ class House {
 	uint8_t getEmptyDoorID() const;
 	Position getDoorPositionByID(uint8_t id) const;
 
+	const PositionList &getTiles() const {
+		return tiles;
+	}
+
 protected:
 	Map* map;
 	PositionList tiles;

source/palette_house.cpp

@@ -322,10 +322,20 @@ void HousePalettePanel::OnListBoxChange(wxCommandEvent &event) {
 }
 
 void HousePalettePanel::OnListBoxDoubleClick(wxCommandEvent &event) {
-	House* house = reinterpret_cast<House*>(event.GetClientData());
-	// I find it extremly unlikely that one actually wants the exit at 0,0,0, so just treat it as the null value
-	if (house && house->getExit() != Position(0, 0, 0)) {
-		g_gui.SetScreenCenterPosition(house->getExit());
+	if (const auto house = reinterpret_cast<House*>(event.GetClientData())) {
+		const Position &position = house->getExit();
+		if (position.isValid()) {
+			g_gui.SetScreenCenterPosition(position);
+			return;
+		}
+
+		// find a valid tile position
+		for (const Position &tilePosition : house->getTiles()) {
+			if (tilePosition.isValid()) {
+				g_gui.SetScreenCenterPosition(tilePosition);
+				break;
+			}
+		}
 	}
 }