[PATCH v4 11/12] mfplat: Return NULL for *stream_sink on error in IMFMediaSink::AddStreamSink.

[Torge Matthies]

From: Torge Matthies

There are tests for this in dlls/mf, however they are gated behind IMFMediaSink::GetCharacteristics succeeding and
the characteristics not containing MEDIASINK_FIXED_STREAMS.
---
 dlls/winegstreamer/media_sink.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/dlls/winegstreamer/media_sink.c b/dlls/winegstreamer/media_sink.c
index 78f8249692d..2300046aaeb 100644
--- a/dlls/winegstreamer/media_sink.c
+++ b/dlls/winegstreamer/media_sink.c
@@ -794,6 +794,9 @@ static HRESULT WINAPI media_sink_AddStreamSink(IMFFinalizableMediaSink *iface, D
     TRACE("iface %p, stream_sink_id %#lx, media_type %p, stream_sink %p.\n",
             iface, stream_sink_id, media_type, stream_sink);

+    if (stream_sink)
+        *stream_sink = NULL;
+
     EnterCriticalSection(&media_sink->cs);

if (media_sink_get_stream_sink_by_id(media_sink, stream_sink_id))