CreateFileMapping returns NULL if failed, but mistakenly tested with INVALID_HANDLE_VALUE in the source code

1968
// first create the file mapping handle
1969
DWORD protection = (openMode & QIODevice::WriteOnly) ? PAGE_READWRITE : PAGE_READONLY;
1970
mapHandle = ::CreateFileMapping(handle, 0, protection, 0, 0, 0);
1971
if (mapHandle == INVALID_HANDLE_VALUE) {
1972
q->setError(QFile::PermissionsError, qt_error_string());

According to MSDN http://msdn.microsoft.com/en-us/library/aa366537(VS.85).aspx
CreateFileMapping
If the function fails, the return value is NULL...