Crash after accessing parts before allocated memory

[Fabian Maurer]

On Friday, November 18, 2016 3:01:57 PM CET Marcus Meissner wrote:
> this is really undefined behaviour ... Can you fix the application?

I'm afraid not. It's a closed source indie game from ~2000, only downloadable 
form third-party sites.

I just did a few tests on windows on a VM, and it seems indeed to be UB. The 
code behaves exactly the same on wine and windows, just the UB is different. I 
mean, I could make a patch - it's just a single bit that needs to be flipped 
(movsx -> movzx) - but that's not a solution for wine.

I'll probably make an appdb entry and provide a hack, but any idea what else I 
could do? I mean, it works on windows/reactos, even if I don't know exactly 
why.