Check vehicle tile hash in CheckCaches

src/openttd.cpp

@@ -1423,6 +1423,11 @@ void CheckCaches(bool force_check, std::function<void(const char *)> log)
 
 	Vehicle *v;
 	FOR_ALL_VEHICLES(v) {
+		extern bool ValidateVehicleTileHash(const Vehicle *v);
+		if (!ValidateVehicleTileHash(v)) {
+			CCLOG("vehicle tile hash mismatch: type %i, vehicle %i, company %i, unit number %i", (int)v->type, v->index, (int)v->owner, v->unitnumber);
+		}
+
 		extern void FillNewGRFVehicleCache(const Vehicle *v);
 		if (v != v->First() || v->vehstatus & VS_CRASHED || !v->IsPrimaryVehicle()) continue;
 

src/vehicle.cpp

@@ -762,6 +762,15 @@ static void UpdateVehicleTileHash(Vehicle *v, bool remove)
 	v->hash_tile_current = new_hash;
 }
 
+bool ValidateVehicleTileHash(const Vehicle *v)
+{
+	if (v->type == VEH_TRAIN && Train::From(v)->IsVirtual()) return v->hash_tile_current == nullptr;
+
+	int x = GB(TileX(v->tile), HASH_RES, HASH_BITS);
+	int y = GB(TileY(v->tile), HASH_RES, HASH_BITS) << HASH_BITS;
+	return v->hash_tile_current == &_vehicle_tile_hash[(x + y) & TOTAL_HASH_MASK];
+}
+
 static Vehicle *_vehicle_viewport_hash[1 << (GEN_HASHX_BITS + GEN_HASHY_BITS)];
 
 static void UpdateVehicleViewportHash(Vehicle *v, int x, int y)