[TYPO3-dev] How to overwrite a class.t3lib_function?

[Thomas Grabietz]

Hello All,
I would like to use multilingual aliases. I've extended my 
page_language_overlay table, but the alias field is not looked up in the 
getPageIdFromAlias($alias) function:

function getPageIdFromAlias($alias)	{
		$alias = strtolower($alias);
		$res = $GLOBALS['TYPO3_DB']->exec_SELECTquery('uid', 'pages', 'alias='.
$GLOBALS['TYPO3_DB']->fullQuoteStr($alias, 'pages').' AND pid>=0 AND 
pages.deleted=0');	// "AND pid>=0" is because of versioning...
		if ($row = $GLOBALS['TYPO3_DB']->sql_fetch_assoc($res))	{
			return $row['uid'];
		}
		return 0;
	}

It's not so dificult to extend this function (to make also a query for the 
alias of the page_language_overlay table), but I don't want to do this in the 
source-code. Is it possible to overwrite the function in an extension? Or any 
other ideas to solve the problem?

Tom