[P-BUG][Player]Zombie hitting a Right facing splitter zombifies far away lemming

[GigaLem]

EDIT by namida: Fix to be included in 12.13.0 12.12.4

Found this out while I was making another level, for some reason if a zombie goes into a right facing splitter, a lemming far away SOMEHOW turns a lemming into zombie.

I've a attached a level below to show this behavior

[namida]

I suspect this is a side effect of the "zombie always infects a blocker they bounce off" fix. Chances are there are further matters needed to set it up than just a zombie and splitter (for example, it probably matters which one spawned first or something like that), given that it took this long to come to light, but having a level that demonstrates the issue should help track that down.

[namida]

Reordering the lemmings (in the level file) does affect this. Some orders raise an entirely different bug. It also appears that the bug occurs (with the same result) when the splitter is left-facing too; however, it only occurs if the splitter actually turns the lemming around (in either direction).

(Z = zombie, L = left blocker, R = right blocker)

ZLR - This one raises a bug where R ends up as a walker rather than a blocker when gameplay starts (however, he's still a blocker on the preview screen). This topic's bug does not occur.
ZRL - This topic's bug occurs, L becomes infected.
LZR - This one also raises the ZLR bug. This topic's bug also occurs, L becomes infected.
RZL - This topic's bug occurs, R becomes infected.
LRZ - The ZLR bug occurs; this topic's bug does not.
RLZ - This topic's bug occurs, L becomes infected.

[namida]

Fixed in commit eb22aa2.

[namida]

Here's an experimental (otherwise identical to 12.12.3) which includes this fix.

I suspect there's little chance that the bug still happens under any circumstances but feel free to test for that anyway. More importantly, I'm interested in determining if there are any side effects. If anyone with a bit of spare time and a good replay collection could try running some mass replay checks with this build and letting me know if anything breaks, that'd be great. The main focus is levels that use blockers - they do not necesserially have to be zombie levels and/or use splitters (as blockers are where I expect side effects are likely to be).

[IchoTolot]

United, Reunion and Lemmings World Tour had no breakages. Will check a few more packs over the weekend.

[Armani]

No issue found in my pack(Lemmings Uncharted), current contest pack, nepsterlems

[IchoTolot]

No issues in DoveLems, PimoLems, SEB Lems and LemRunner. 

[namida]

Alright, I think it's safe to say that the fix is safe at this point. I'll put together a 12.12.4 update tomorrow; in the meantime feel free to use the above exp to test any levels that are otherwise unplayable due to this bug in the meantime.