winegstreamer: Return NS_E_INVALID_REQUEST on WMReader Start before Open.

dlls/winegstreamer/wm_asyncreader.c

@@ -318,6 +318,13 @@ static HRESULT WINAPI WMReader_Start(IWMReader *iface,
 
     EnterCriticalSection(&reader->reader.cs);
 
+    if (!reader->reader.wg_parser)
+    {
+        LeaveCriticalSection(&reader->reader.cs);
+        WARN("No stream is open; returning NS_E_INVALID_REQUEST.\n");
+        return NS_E_INVALID_REQUEST;
+    }
+
     stop_streaming(reader);
 
     IWMReaderCallback_OnStatus(reader->callback, WMT_STARTED, S_OK, WMT_TYPE_DWORD, (BYTE *)&zero, context);

dlls/wmvcore/tests/wmvcore.c

@@ -2171,6 +2171,8 @@ static void test_async_reader_streaming(void)
 
     hr = IWMReader_Stop(reader);
     ok(hr == E_UNEXPECTED, "Got hr %#lx.\n", hr);
+    hr = IWMReader_Start(reader, 0, 0, 1.0, NULL);
+    ok(hr == NS_E_INVALID_REQUEST, "Got hr %#lx.\n", hr);
 
     hr = IWMReaderAdvanced2_OpenStream(advanced, &stream.IStream_iface, &callback.IWMReaderCallback_iface, (void **)0xdeadbeef);
     ok(hr == S_OK, "Got hr %#lx.\n", hr);