TYPO3 Core

The error occours if the given page uid is the frontpage and in conjunction with realURL the suffix is blank to the base URL.

Interesting is that the problem does not occur in an analogous case with links in the menues, wich point also to the frontpage. Here is the base-url added to the links. Perhaps is this a hint to the solution (see above).

Maybe the problem for menues was solved at 2004-09-11 (see the changelog for typo 3.8.0):
"Fixed problem with empty URLs in menu generation. Empty URLs may occur when a realurl points to the frontpage (which is a blank suffix to the base url). In such cases the URL now becomes the baseUrl of the site (if that is configured!). This should fix it very specifically for all realurl cases."

Perhaps is this a hint to the solution.

An example for this bug is shipped with the extension masi_metatags_nav, where with code like
$top = reset($GLOBALS['TSFE']->config['rootLine']); $typolink = $this->typolink_URL(array('parameter'=>$top['uid'])); $contentArray[] = '<link rel="top" href="'.$this->lastTypoLinkUrl.'" title="'.$top['title'].'" />';
a link to the top page is generated. In conjunction with realURL is the value of the href-attribute empty and not valid.
(issue imported from #M1521)