[kovarex] [1.1.12] Crash trying to merge two belts (UndergroundBelt::findConnectionCandidateOrBlocker)

[poiuqwer78]

Crash upon trying to build two belts one coming from north, one coming from south to merge to one belt going east, to fill two lanes with different products. Before the crash, an underground belt was automatically placed, but it should not do this.

In general: How can such a setup be built without triggering automatic underground belts? Only option i found was to place it differently and then rotate the individual belt segments.

how_to_build_this.png (113.12 KiB) Viewed 1567 times

Crash report attached. as well as savefile.

[bormand]

Could you remember an order in which you built belts?

I built this setup (edit: in vanilla, not your save) without any problems (build an output lane, connect north, connect south). Underground appears only if I move mouse too far, onto another side of the belt.

[poiuqwer78]

Tried to build in different orders, always ending up with an underground belt, until it then crashed. Couldn’t build it after the crash either, except by building it such that the south belt goes down and then rotate it up

[kovarex]

Hello, I can't simulate any crash, nor undergound belts being created when I make this setup. I would need some more detailed instructions.

[poiuqwer78]

Hi!

Just tried to reproduce on a fresh game withouts mods, and it doesn't occur. Also, it doesnt occur on older saves with all mods activated. I found the earliest backup in which it started to show this behavior. Any later save of that map shows this behavior, it seems to be dependent on the specific savegame.

What to do:
Place a belt pointing south, and then a belt pointing north two tiles below, it creates an underground connection (it should just place the belts and leave an empty spot in the middle). Usually, this doesnt crash the game, but doing it more than once in the same spot crashes the game.

Attached the save that triggers this behavior and the new crash report. (reproduced on that savegame)

EDIT: Unfortunately, I just realized the reason it didn't happen in other saves was the lack of underground belts in the inventory. I can reproduce the behavior (not the crash) on a fresh save. Creating a single belt south and a single belt north two tiles below creates an underground belt. Not sure why.