winegstreamer: Return E_UNEXPECTED when calling IWMReader::Stop() if no stream is open.

dlls/winegstreamer/wm_asyncreader.c

@@ -356,6 +356,14 @@ static HRESULT WINAPI WMReader_Stop(IWMReader *iface)
     TRACE("reader %p.\n", reader);
 
     EnterCriticalSection(&reader->reader.cs);
+
+    if (!reader->reader.wg_parser)
+    {
+        LeaveCriticalSection(&reader->reader.cs);
+        WARN("No stream is open; returning E_UNEXPECTED.\n");
+        return E_UNEXPECTED;
+    }
+
     stop_streaming(reader);
     IWMReaderCallback_OnStatus(reader->callback, WMT_STOPPED, S_OK,
             WMT_TYPE_DWORD, (BYTE *)&zero, reader->context);

dlls/wmvcore/tests/wmvcore.c

@@ -2169,6 +2169,9 @@ static void test_async_reader_streaming(void)
     IWMReader_QueryInterface(reader, &IID_IWMProfile, (void **)&profile);
     IWMReader_QueryInterface(reader, &IID_IWMReaderAdvanced2, (void **)&advanced);
 
+    hr = IWMReader_Stop(reader);
+    ok(hr == E_UNEXPECTED, "Got hr %#x.\n", hr);
+
     hr = IWMReaderAdvanced2_OpenStream(advanced, &stream.IStream_iface, &callback.IWMReaderCallback_iface, (void **)0xdeadbeef);
     ok(hr == S_OK, "Got hr %#x.\n", hr);
     ok(stream.refcount > 1, "Got refcount %d.\n", stream.refcount);
@@ -2257,6 +2260,9 @@ static void test_async_reader_streaming(void)
     ok(callback.refcount == 1, "Got outstanding refcount %d.\n", callback.refcount);
     callback_cleanup(&callback);
 
+    hr = IWMReader_Stop(reader);
+    ok(hr == E_UNEXPECTED, "Got hr %#x.\n", hr);
+
     ok(stream.refcount == 1, "Got outstanding refcount %d.\n", stream.refcount);
     CloseHandle(stream.file);
     ret = DeleteFileW(filename);