[Bug 58276] New: pulse.c should silence_buffer after calloc

[WineHQ Bugzilla]

http://bugs.winehq.org/show_bug.cgi?id=58276

Bug ID: 58276
           Summary: pulse.c should silence_buffer after calloc
           Product: Wine
           Version: 8.0
          Hardware: x86
                OS: Linux
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: winepulse.drv
          Assignee: [e-mail]
          Reporter: [e-mail]
      Distribution: ---

When pulse_write is “prebuffering … frames of silence,” it uses calloc to zero
out a buffer, then immediately calls pa_stream_write.

This isn’t correct for an unsigned 8-bit (u8) stream, since the neutral value
should be 128 instead of zero. This causes noticeable clicking whenever the
sender stops or resumes playback. (For example, old games that play occasional
WAV files as sound effects.) The issue can be reproduced using Sound Recorder
from Win3.1 and an 8-bit mono WAV file. Play the same sound over and over until
it starts clicking/popping.

I’m not sure if this scenario (the end of a WAV file) should even trigger
“buffer underrun” logic at all, since it’s an intentional gap. But regardless
of the reason for the underrun, there should be a silence_buffer call there.

I tested this in Wine 8, but confirmed the logic is the same in the latest
version.