Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=56186
A regular build did not show this failure, but was quite nicely reproducible in my ASan tree. Probably it fills new allocations with some fill bytes.
[The pattern page](https://test.winehq.org/data/patterns.html#dmusic:dmusic) shows currently just two of this test failures.
[Testbot run](https://testbot.winehq.org/JobDetails.pl?Key=158383) with this patch.