TYPO3 Core

Running TYPO3 4.0.2 behind a proxy the domain in the browser and the HTTP_HOST server value in PHP may be different (browser: www.domain.tld, php/server: typo3.domain.tld). TYPO3 doesn't care about this since all paths etc. are relative and so everthing in the FE and BE works fine. But htmlarea (1.4.2) works with absolute urls which causes problems when working with Firefox (1.5 & 2.0). If you click on a content element for editing only the loading message appears while the editor itself doesn't start (no errors in the js console!). When trying to do the some thing with the Internet Explorer (6.0 & 7.0) everything works as expected.
Maybe this behaviour in the Firefox is a bug, but it would be nice to have a way around it...

(issue imported from #M4542)