Comment 13 for bug 356687

There is a function pulse_prepare in the file pcm_pulse.c in ftp://ftp.alsa-project.org/pub/plugins/alsa-plugins-1.0.18.tar.bz2. I'm not sure which Ubuntu package that corresponds to, but it might be libasound2-plugins or libasound2.
Could the bug be in that package, rather than pulseaudio?

Some lines from the source.
err =
     pulse_wait_stream_state(pcm->p, pcm->stream, PA_STREAM_READY);
 if (err < 0) {
  SNDERR("PulseAudio: Unable to create stream: %s\n", pa_strerror(pa_context_errno(pcm->p->context)));
  pa_stream_unref(pcm->stream);
  pcm->stream = NULL;
  goto finish;
 }

The function pulse_wait_stream_state is defined in pulse.c in the same package.
It uses the function pulse_check_connection(), which is defined in the same file, and if that function succeeds, pa_threaded_mainloop_wait() is called, but I don't think that happens.

My understanding of C ends there, and i was unable to see where Alsa called pulseaudio. Hope this helps someone.

The file shm.c could be a part of the packate tendra, which a free C/C++ compiler built around the TDF/ANDF format
which provides strict conformance checks for a range of APIs. Among those currently supported are ANSI and ISO C, POSIX 1 & 2, System V, Unix95, XPG3 and XPG4.
It doesn't sound relevant to the bug.