[PATCH] libmyth: Prevent an access violation by the ALSA library

[Lawrence Rust <lvr@…>]

In audiooutputalsa.cpp, AudioOutputALSA::GetDevices calls the ALSA API snd_device_name_hint with a card index of -1 to obtain a list of hints for all cards. Unfortunately, with libasound.so.2.0 this API can cause an access violation when the card index is -1. See ​http://code.google.com/p/chromium/issues/detail?id=95797

Running with valgrind shows that snd_device_name_hint makes reference to previously freed memory when called with a card index of -1.

This patch enumerates the cards using other ALSA APIs, thus avoiding the SEGV.

The access violation is often seen when starting from an empty dbase and attempting to enter the audio setup screen. The bug also applies to fixes/0.25 and 0.24.

[JYA]

Interesting...

That specific code is a direct rip of alsautils' aplay -L that lists all the devices

[Lawrence Rust <lvr@…>]

Updated patch fixes a problem where not all devices were enumerated.

[JYA]

Fixed in c35c00385f781e6736026848d54d75ffa6006219

Thanks for the patch