/// message handler to check if a file exists
/// \param size - size of a CHECKFILEEXISTS
/// \param param - pointer to a CHECKFILEEXISTS struct
/// \return MSG_XXX return value
DWORD CZLibStreamFactory::OnCheckFileExists(DWORD size, void *param)
{
	VERIFY_MESSAGE_SIZE(size, sizeof(CHECKFILEEXISTS));
	CHECKFILEEXISTS &cfe = *(CHECKFILEEXISTS*)param;

	StdString sPath = cfe.pFilePath;
	sPath.MakeSafeFileName();
	sPath.ConformSlashesForward();

	if( CZipFileStream::CheckFileExist( sPath.c_str() ) )
	{
		cfe.bExists = true;
		return MSG_HANDLED_STOP;
	}
	
	cfe.bExists = false;
	return MSG_HANDLED_PROCEED;
}