Maniac Mansion [Apple IIgs] : Game crash when accessing garage

[laurentlasalle]

I'm unable to access the garage scene in the Apple IIgs version of Maniac Mansion under ScummVM 2.1 and 2.2 (ERROR: Cannot read resource). I get normal behaviour under ScummVM 2.0. I am using Windows 10.0.18362.

FYI, I tried 2 different dumps of the game, one where maniac1.dsk is CRC32: 15798A84 and another with CRC32: 6A61FF48. Both maniac2.dsk files are identical, with a checksum of CRC32: DE0A27E2. Same result in both cases.

I'm including a save file from the storage room with the pool door unlocked and open. Just walk in the pool scene, open the yellow gate, and try to access the garage scene.

[laurentlasalle]

Interesting notes. I did a comparison with --debuglevel=9 on both ScummVM 2.0 and 2.2, and got a glimpse of what the issue might be.

This is where ScummVM 2.2 crashes :

[2020-05-04 19:50:53] loadResource(Sound,40)
[2020-05-04 19:50:53] openRoom(16)
[2020-05-04 19:50:53] _res->createResource(Sound,40,21)
[2020-05-04 19:50:53] loadResource(Sound,64)
[2020-05-04 19:50:53] openRoom(16)
[2020-05-04 19:50:53] _res->createResource(Sound,64,5)
[2020-05-04 19:50:53] loadResource(Sound,68)
[2020-05-04 19:50:53] openRoom(16)
[2020-05-04 19:50:53] _res->createResource(Sound,68,52428)

And here is the equivalent in ScummVM 2.0 :

[2020-05-04 20:35:39] loadResource(Sound,40)
[2020-05-04 20:35:39] openRoom(16)
[2020-05-04 20:35:39] _res->createResource(Sound,40,21)
[2020-05-04 20:35:39] loadResource(Sound,64)
[2020-05-04 20:35:39] openRoom(16)
[2020-05-04 20:35:39] _res->createResource(Sound,64,5)
[2020-05-04 20:35:39] loadResource(Sound,68)
[2020-05-04 20:35:39] openRoom(16)
[2020-05-04 20:35:39] _res->createResource(Sound,68,0)

Is 52428 a normal length for sound resource?

[laurentlasalle]

Typing "room 16" command from the console window can be use as a quicker way to reproduce the bug.

[sev-]

Actually, it was an accident that it was working in 2.0. I just checked back in history, and it never worked properly. I can reproduce it on Mac only with Address Sanitizer, which tells me that most probably there is an uninitialized memory somewhere.

I'll keep digging.

[sev-]

Okay, I fixed it in 1a6ffd6398339a82e79817c065bb0ae926dd4b63. That sound resource is incorrect, having no size. Thus, we were reading random stuff and that led to this behaviour.