AI cargo ships get stuck on approaching player owned factory

[douglasg14b]

Just made some factories, logged off, then came back to an AI cargo ship stuck beside every one of my factories/mines. Some several Km away, some within their tractor-beam range.

 

While these traders are here, no others come to trade with the factories.

 

I've tried bumping them, and removing and replacing all docks on the factories. On only a single factory, the "stuck" ship vanished after replacing all docks and a while later a new trader came, and continued the normal cycle. All other factories still have stuck traders.

 

Some other reports:

 

https://steamcommunity.com/app/445220/discussions/0/2906376154325005405

 

https://steamcommunity.com/app/445220/discussions/1/1618346571421896528

 

https://steamcommunity.com/app/445220/discussions/1/1489992713692832149

 

https://www.avorion.net/forum/index.php?topic=2587.0

 

Reproduction Steps:

 

This can be reproduced by unloading a sector while an AI trader is approaching a factory. They can be in the approaching stage, or in the tractor-beaming stage. When you load the sector again, the ships will be stuck, and no other trades will occur.

 

 

Relevant Log Entry:

 

I received this error once, and only once. I am not sure what triggered it, but I have been unable to get this error to show back up in the logs since it's first occurrence.

 

2018-01-28 03-24-11| could not execute function 'updateServer' in '"data/scripts/entity/merchants/tradeship.lua"':
2018-01-28 03-24-11| vector::_M_range_check: __n (which is 1) >= this->size() (which is 1)
2018-01-28 03-24-11| 	[C]:-1: in function isDockFree
2018-01-28 03-24-11| 	data/scripts/entity/ai/dock.lua:31: in function flyToDock
2018-01-28 03-24-11| 	data/scripts/entity/ai/trade.lua:75: in function updateServerAI
2018-01-28 03-24-11| 	data/scripts/entity/merchants/tradeship.lua:62: in function ?
2018-01-28 03-24-11| Setting state to invalid.

[Shrooblord]

Have you installed the latest Beta patch? Its changelog describes that the devs fixed this issue:

[uBR] Fixed an issue where trading ships would get stuck and block docking ports

[douglasg14b]

Thanks!

 

I migrated the fixes over without upgrading to the beta branch, works like a charm.

[Shrooblord]

As you have, I'm curious, what change in the code caused this behaviour to be fixed? Could you post a diff?