[Kovarex] [14.21] Desync on placing signal into crash: "ManualBuilder::canBuildCollisionCheck"

[Quaternions]

Placing the rail chain signal causes the desync. I reproduced this bug three times. It does not happen if the two signals are placed in the opposite order. After the desync, the chain signal has disappeared and the regular signal is not rotated how I placed it, so I assume it's related to an illegal placement detection.

https://youtu.be/zAX7tM8797U

factorio-current.log

log file

(245.66 KiB) Downloaded 175 times

[Loewchen]

Please post the desync report, see my signature on where to find it.
You can produce the desync reliably?

[Quaternions]

Here is the latest desync report of the three. Tell me if you want the other two. I desynced a couple times earlier in the server too... but either I didn't see the pattern yet or it was unrelated. The desync was on command in that instance, I did it three times to test it.

https://drive.google.com/open?id=0B7cKj ... TloTnZtQXM

Edit: Oh right, the game crashed a few moments after I pressed reconnect which appeared after the third desync because of too many desyncs.

Second Edit: The desync happened again in a different spot, same sort of thing. I had someone else place the signals and they got a desync too!

[kovarex]

Thanks for the report, I fixed it for the next version (probably 0.14.22)