[OLE32] Fix a crash when executing zz_winrar_3.80_test.exe 4.drag_and_drop CORE-12590 #resolve

svn path=/trunk/; revision=73906

reactos/dll/win32/ole32/clipboard.c

@@ -807,6 +807,9 @@ static HRESULT get_data_from_global(IDataObject *data, FORMATETC *fmt, HGLOBAL *
 
     mem_fmt = *fmt;
     mem_fmt.tymed = TYMED_HGLOBAL;
+#ifdef __REACTOS__
+    med.pUnkForRelease = NULL;
+#endif
 
     hr = IDataObject_GetData(data, &mem_fmt, &med);
     if(FAILED(hr)) return hr;