alsa-lib 1.2.2 kills my unity3d games

[Jaroslav Kysela]

Dne 29. 02. 20 v 21:19 Thomas J. Moore napsal(a):
> Sorry if this has already been reported, but I only really subscribed to
> report this bug, and nothing recent in the archive jumped out at me.
> 
> Some time after Jan 12, some change in my (Gentoo Linux) system caused
> 67 of my 72 commercial, closed-source unity3d games to crash on startup.
>    gdb was no help, but strace showed alsa activity before two crashes,
> and, sure enough, reverting alsa-lib to 1.2.1.2 cured it.
> 
> I bisected to this commit (5ee5ef31b "namehint: correct the @args check"):
> 
> https://git.alsa-project.org/?p=alsa-lib.git;a=blobdiff;f=src/control/namehint.c;h=4927ef973c326bef41e33b87714de87b31c1f752;hp=808df6b507336b8f6d6e618a0cfa520d62a3b4fc;hb=5ee5ef31b5ff3fb7c904054cb9cac7478a727f7c;hpb=ebdd2b6cdb8119cf75f0dd0a3b283d271b3a547e
> 
> I don't know what the exact problem is, but reverting just this commit
> was enough to make everything work again (and its later modification in
> 6055f8a58 which doesn't make sense looking at the code as the function
> always returns 0 and str may still be NULL on exit, but adding a check
> for NULL str is not enough to stop unity3d from crashing).

The revert does not resolve the culprit. I already posted my comments to
https://github.com/alsa-project/alsa-lib/issues/27 . It's difficult to fix 
something without sources. The bug seems to be in the sound device enumeration 
in the commercial binary.

The alsa-lib's change just returns more devices than the previous version. It 
should not affect anything. The device list collected from the affected 
application in the comment bellow looks really suspicious:
   https://github.com/alsa-project/alsa-lib/issues/27#issuecomment-592920831

It appears that the code does really something unwanted. You can find 
workarounds in the issue.

					Jaroslav

-- 
Jaroslav Kysela <perex at perex.cz>
Linux Sound Maintainer; ALSA Project; Red Hat, Inc.