mf/session: Handle error when a source fails to start.

dlls/mf/session.c

@@ -920,7 +920,11 @@ static void session_start(struct media_session *session, const GUID *time_format
             LIST_FOR_EACH_ENTRY(source, &session->presentation.sources, struct media_source, entry)
             {
                 if (FAILED(hr = IMFMediaSource_Start(source->source, source->pd, &GUID_NULL, start_position)))
+                {
                     WARN("Failed to start media source %p, hr %#lx.\n", source->source, hr);
+                    session_command_complete_with_event(session, MESessionStarted, hr, NULL);
+                    return;
+                }
             }
 
             session->state = SESSION_STATE_STARTING_SOURCES;

dlls/mf/tests/mf.c

@@ -2514,7 +2514,7 @@ static void test_media_session_events(void)
     hr = IMFMediaSession_Start(session, &GUID_NULL, &propvar);
     ok(hr == S_OK, "Unexpected hr %#lx.\n", hr);
     hr = wait_media_event_until_blocking(session, callback, MESessionStarted, 1000, &propvar);
-    todo_wine ok(hr == E_NOTIMPL, "Unexpected hr %#lx.\n", hr);
+    ok(hr == E_NOTIMPL, "Unexpected hr %#lx.\n", hr);
     ok(propvar.vt == VT_EMPTY, "got vt %u\n", propvar.vt);
     ok(propvar.punkVal != (IUnknown *)topology, "got punkVal %p\n", propvar.punkVal);
     PropVariantClear(&propvar);