[PATCH v3 1/1] mf/session: Avoid dropping samples delivered from transform in session_request_sample_from_node().

[Paul Gofman]

From: Paul Gofman

session_request_sample() calls session_request_sample_from_node() and increments sink.requests
only if that succeeds. But session_request_sample_from_node() calls session_deliver_sample_to_node()
synchronously for MF_TOPOLOGY_TRANSFORM_NODE if there are output samples available. Then,
if sink.requests is zero before this session_request_sample() call that sample is silently dropped.
---
 dlls/mf/session.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/dlls/mf/session.c b/dlls/mf/session.c
index b2371763150..85baf07d05a 100644
--- a/dlls/mf/session.c
+++ b/dlls/mf/session.c
@@ -3388,8 +3388,9 @@ static void session_request_sample(struct media_session *session, IMFStreamSink
         return;
     }

-    if (SUCCEEDED(session_request_sample_from_node(session, upstream_node, upstream_output)))
-        sink_node->u.sink.requests++;
+    sink_node->u.sink.requests++;
+    if (FAILED(session_request_sample_from_node(session, upstream_node, upstream_output)))
+        sink_node->u.sink.requests--;
     IMFTopologyNode_Release(upstream_node);
 }