TYPO3 Core

In \TYPO3\CMS\Core\Html\RteHtmlParser::TS_links_db() <a> tags are parsed and their "href" attributes analysed for URNs. With strict typing introduced with the usage of PHP 7, \TYPO3\CMS\Core\LinkHandling\LinkService::resolve() now requires the argument it receives to be a string.

However it may happen that the content of the RTE contains <a> tags with no "href" attribute. In my case it happened when pasting content from LibreOffice, which added an empty <a> tag after each <h*> tag. In this case, a PHP error will happen, because the "href" part of the link information is null.

I propose adding a simple check, passing an empty string to the \TYPO3\CMS\Core\LinkHandling\LinkService::resolve() call if the the "href" information is null.

How to test: prepare some HTML content to paste into the RTE with an empty <a> tag and save the content element.