[boskid][1.1.6] crc failure in multiplayer on tree_stage_index increment and game.force_crc()

[max2344]

Hi,

during bug squashing in Treeees upon the bug report[1] we found that increasing tree_stage_index of a tree entity leads to a desync in multiplayer. At the same time, issuing these commands on the console doesn't lead to the described behavior. We expect the tree_stage_index to be synced across the clients at some time, so that does not lead to errors. We consider this state variable being part of the map data. The proof of concept for this bug is attached in form of a mod. The error happens whenever tree_stage_index is increased and a CRC check is ran. To reproduce this behavior reliably you need to install the mod we attached, start a multiplayer game and connect more than 1 player. Upon crc check issued either by script or by console command the joined players disconnect due to a desync. We consider this behavior being a bug.

Kind regards,

-max2344, dodo.the.last

[1] https://mods.factorio.com/mod/Trees/dis ... 170b3c6216

[boskid]

Thanks for the report. Issue is now fixed for 1.1.7.

I was trying to find a nice workaround for you however it looks writing to LuaEntity::tree_stage_index is pretty much busted in versions <= 1.1.6.