[2.1.7] Upgrading a train that is parked on a crossing non-elevated rails causes rolling stock to disconnect

[vmainen]

Minimal example blueprint:

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

Copy blueprint

Reproduce:

1. Place the blueprint (or replicate what you see in image).
2. Use upgrade planner to upgrade the whole train.
3. The train splits in three, only the first wagon is connected, the two latter cars are a single section each.
4. The front part of the train still leaves on schedule (not in this blueprint though, but my railnetwork is full of disconnected trains now).

Possibly related to: viewtopic.php?t=134143

[Rseding91]

This looks like a failure of the rolling stock joint system itself. The whole "on curves, the rolling stock render differently compared to their actual position". If you remove any of the middle cargo wagons and attempt to manually re-build them they will never re-connect the train properly. The upgrade logic just gets caught in the cross-fire of that issue.

[vmainen]

Here's two other, not-so-convoluted examples from a real game.

In barely-on-curve.png the locomotive is barely on the curve, but the train that was in front of it has been disconnected and then it started driving. The train used to be 2-8-2 so 2 locomotives on each end.

stupidstacker.png does not display a problem right now, but it's another place where I saw this happening. The 1-4 trains had been turned to 1-2 trains because it cuts at the curve again. I call the example stupidstacker, because due to space restrictions I had to build it like that, so the parked train is still on the stacker.

[boskid]

Thanks for the report. Issue is now fixed for 2.1.8.