help with fixing desync

[rootbeer23]

Hi.

I am currently researching the evil replay desync bug. and i have a plan.
actually i have already 2 plans, so this is not just a waste of time.
You can help, all you need is http://wireshark.org and a few minutes time.

The plan would be:

1) put on your labcoat
2) gather in a team of 3 labrats, but maybe 2 are enough, since a sandbox game doesnt end when only one is left.
3) start wireshark and record FA network traffic, the filter should look something like 'udp and udp.port==6112',
make sure that you are not connected by proxy
4) start a sandbox game, cheat a few hundred units and give a lot of commands to the units.
5) suddenly alt+f4. this seems to make desyncs more likely.
6) post the .fafreplay and the wireshark dump in this thread.

if there is no desync in the replay, i'll take it and the packet dump too for comparisons.
you can leave wireshark running and play a few testgames. i will figure out where the games start myself.

for the curious, plan A is to compare whats on the wire with whats in the replay with extra
focus on the connection teardown procedure and the commands that are on the wire near the disconnect.
plan B would be to generate the packets that a disconnecting peer would send, and so to fool FA.exe
into thinking that no peer actually disconnected.
https://github.com/FAForever/lobby/wiki/Desyncs

and for a bit more context on the protocol
https://github.com/FAForever/lobby/wiki/Compression

Happy bughunting!