Zhiyi Zhang (@zhiyi) commented about dlls/winegstreamer/wm_reader.c:
return E_OUTOFMEMORY; *size = sizeof(stream_mt) + stream_mt.cbFormat; if (!mt)
Let's return early when !mt is true and call FreeMediaType(&stream_mt) when req_size < *size so that stream_mt is not leaked on these branches as well.