mf/topoloader: Set MF_TOPONODE_MEDIASTART for all source nodes.

dlls/mf/tests/mf.c

@@ -2136,6 +2136,7 @@ static void test_topology_loader_evr(void)
     IMFTopoLoader *loader;
     IMFMediaSink *sink;
     WORD node_count;
+    UINT64 value64;
     HWND window;
     HRESULT hr;
 
@@ -2232,6 +2233,13 @@ todo_wine
             ok(hr == S_OK, "Unexpected hr %#x.\n", hr);
             ok(!value, "Unexpected stream id %u.\n", value);
         }
+        else if (node_type == MF_TOPOLOGY_SOURCESTREAM_NODE)
+        {
+            value64 = 1;
+            hr = IMFTopologyNode_GetUINT64(node, &MF_TOPONODE_MEDIASTART, &value64);
+            ok(hr == S_OK, "Unexpected hr %#x.\n", hr);
+            ok(!value64, "Unexpected value.\n");
+        }
     }
 
     IMFTopology_Release(full_topology);

dlls/mf/topology.c

@@ -2380,10 +2380,16 @@ static void topology_loader_resolve_complete(struct topoloader_context *context)
 
             if (node_type == MF_TOPOLOGY_OUTPUT_NODE)
             {
-                /* Make sure MF_TOPONODE_STREAMID is set for all outputs. */
+                /* Set MF_TOPONODE_STREAMID for all outputs. */
                 if (FAILED(IMFTopologyNode_GetItem(node, &MF_TOPONODE_STREAMID, NULL)))
                     IMFTopologyNode_SetUINT32(node, &MF_TOPONODE_STREAMID, 0);
             }
+            else if (node_type == MF_TOPOLOGY_SOURCESTREAM_NODE)
+            {
+                /* Set MF_TOPONODE_MEDIASTART for all sources. */
+                if (FAILED(IMFTopologyNode_GetItem(node, &MF_TOPONODE_MEDIASTART, NULL)))
+                    IMFTopologyNode_SetUINT64(node, &MF_TOPONODE_MEDIASTART, 0);
+            }
 
             IMFTopologyNode_Release(node);
         }