Fix malloc in filesystem_engine

[chinese-soup]

Hi, this fixes the startup aborts that randomly happened and also the shutdown aborts that happened 100% of the time.

[tomkidd]

That explosion you're hearing is the sound of my hand smacking my forehead.

For some reason it took me months to even notice this PR and then more months to getting around to actually doing something with it. And all to discover I'm not as good with C strings as I thought.

Belated thanks for this, now I can have the bundle launch Blue Shift and Opposing Force.

[tomkidd]

@chinese-soup can you take a look at the most recent code and see if I'm doing anything wrong? I had to modify things a bit to account for the latest project changes and everything works... except now when I load it from /Applications it crashes some amount of the time with a malloc error

xash3d(55557,0x1fd9d2080) malloc: Heap corruption detected, free list is damaged at 0x600003b5c2a0
*** Incorrect guard value: 7816388778761871736
xash3d(55557,0x1fd9d2080) malloc: *** set a breakpoint in malloc_error_break to debug

The "guard value" and the hex value are different every time but it seems like it's related to the file changes again, specifically filesystem_engine.c. I ran into an issue on some Macs where it would append more than just the necessary bits so setting the value I needed to '\0' seemed to have done the trick - unless launched from the /Applications folder.

I have a feeling it's something quick/dumb but I'm not sure what.

[tomkidd]

Odder still - it seems as if it runs fine from, say, a zip file from the Downloads folder (as in, the origin of the app bundle is a zip file and you unzip it into the Downloads folder) it is less likely to crash than, say, if it's launched from the Downloads folder but came there via a DMG, or if either ZIP or DMG versions are run from the /Applications folder. Which makes me think something it's doing or something I'm doing is upsetting a security feature in macOS, I just don't know what.

https://github.com/MacSourcePorts/xash3d-fwgs/releases/tag/v0.20-2023-09-25

Also I tried removing the line that adds '\0' and it still does the same thing.

And I just checked and yeah the version I built locally has issues in /Applications too. Very odd.

[tomkidd]

OK yeah, figured it out - it was a different place where I needed to do the same thing. It's just that it's been so long that after all the merging I lost track of what I put in there versus what was already in there. Or at least that's the story I'm going with.

7f7c115