Openapoc: Vehicle pathfinding returns wrong path, causes stuck vehicle

[ashenomo]

I found this stuck vehicle while debugging https://github.com/OpenApoc/OpenApoc/issues/395 , so this may be related to destroyed tiles.

Savegame: The same one from https://github.com/OpenApoc/OpenApoc/issues/395#issuecomment-428932936
Also attached here: save_SuperHuman.1.zip

At the top left corner of the city, there's a Transtellar Spacelines spaceport. There's a construction vehicle stuck above it, oscillating between two tiles.

It's at (29,105,2) or (29,105,3) and is trying to go to (29,69,2):

W 116304142941 bool OpenApoc::CityView::handleMouseDown(OpenApoc::Event *): CLICKED VEHICLE Construction Vehicle 23 at {29.5,105.5,3.20833}
W 116304237372 bool OpenApoc::CityView::handleMouseDown(OpenApoc::Event *): Mission GotoLocation (rra:0) {29,69,2}
W 116304350828 bool OpenApoc::CityView::handleMouseDown(OpenApoc::Event *): Mission GotoBuilding (rra:0) BUILDING_WAREHOUSE_TWO

findShortestPath is being called with the correct parameters, but it's returning a path to (29,105,2) or (29,105,3), whichever was not the starting position.

I 301092281835 std::list<Vec3<int> > OpenApoc::TileMap::findShortestPath(Vec3<int>, Vec3<int>, Vec3<int>, int, const OpenApoc::CanEnterTileHelper &, bool, bool, bool, bool, float *, float): Trying to route from {29,105,2} to {29,69,2}
I 301093188364 std::list<Vec3<int> > OpenApoc::TileMap::findShortestPath(Vec3<int>, Vec3<int>, Vec3<int>, int, const OpenApoc::CanEnterTileHelper &, bool, bool, bool, bool, float *, float): No route from {29,105,2} to {29,69,2}-{30,70,3} found after 51 iterations, returning closest path {29,105,3}

At game time 10:31:13, it magically recovers:

I 1198330487133 std::list<Vec3<int> > OpenApoc::TileMap::findShortestPath(Vec3<int>, Vec3<int>, Vec3<int>, int, const OpenApoc::CanEnterTileHelper &, bool, bool, bool, bool, float *, float): Trying to route from {29,105,3} to {29,69,2}
I 1198331343798 std::list<Vec3<int> > OpenApoc::TileMap::findShortestPath(Vec3<int>, Vec3<int>, Vec3<int>, int, const OpenApoc::CanEnterTileHelper &, bool, bool, bool, bool, float *, float): No route from {29,105,3} to {29,69,2}-{30,70,3} found after 51 iterations, returning closest path {32,99,6}

There are no visible changes to the path in between. Some tiles at unrelated locations on the map are destroyed just before pathfinding recovers.

[FilmBoy84]

Possibly also related to issues #484 #364 #339

Ethan has found another example of this bug, again with a construction vehicle but this time trying to use an occupied landing pad

Save is here
https://cdn.discordapp.com/attachments/376028757183561728/612037753013665806/save_Bug_Save.save