Fixed a crash when trying to capture husks that have been destroyed.

[Mailaender]

as desribed in #5793 and #5638.

[phrohdoh]

World: is syntax for a yaml trait.
Maybe Attach this to the world actor would be better?

[Mailaender]

Okay.

[chrisforbes]

Two problems here:

1. IsDead() isn't the correct check since we certainly do want to remove "dead" buildings from BuildingInfluence if they take this path -- you want Destroyed, which is what matters for whether a trait lookup is going to explode on you.

2. This is papering over a logic bug in husk capturing. Units shouldn't have their traits destroyed prior to being removed from the world.

[Mailaender]

Updated. I hope this fixes the problem as a whole. Looks the removal from the world and immediate adding back during owner change was causing breakage everywhere when the actor has already been destroyed. Looks like BuildingInfluence was just the first one being notified and stumbling over it then.

[pchote]

I think @chrisforbes's point 2) is the key thing here.

This crash will be occurring when someone captures a husk in the same tick that it is killed and removed from the map. The current checks will prevent the crash, but it will also cause the engineer/mechanic to be consumed with no tank to show for it.

A much better fix for this crash would be to add an IsDead check to CaptureActor.cs:L42.

[Mailaender]

I added additional checks. Now every AddFrameEndTask should be safe.

[pchote]

Confirmed that this fixes the crash and that engineers/mechanics aren't consumed when this case is hit. Thanks.

[pchote]

https://github.com/OpenRA/OpenRA/wiki/Changelog/_compare/42678f217d0b4a7f6808108dfe0911a82b01b8cb%5E...42678f217d0b4a7f6808108dfe0911a82b01b8cb