TYPO3 Core

It depends on the static template "Clickenlarge Rendering". If i include this static template the img tag will be invalid.

Tested in version 4.4.4: When static for clickenlarge is place before that of css_styled_content the output of the image tag is correct xhtml.

Are you using DAM?

In the above mentioned setting, we do not use DAM.
I tested it in another 4.4.4 installation, where we do uses DAM: There the img tag ends correctly, even the static of clickenlarge comes after that of css_styled_content.
But clickenlarge does not work there at all. Most of the time I do not even get the pop-up for setting the image properties in the rte (but the dam-adjusted element browser). Once I got to that point, marked clickenlarge, but in the FE it did not work. In the img tag a have a property clickenlarge="1" as a result.
Besides that, the image tag is not valid there, because "there is no attribute tx-dam" - but that is a different story I guess.

Static template "Clickenlarge Rendering" must be included AFTER static template "CSS Styled Content" otherwise the setup is erased by CSS Styled Content.

HTMLparser produces incorrect output when given a configuration for an empty tag such as the img tag. Both htmlArea RTE and DAM define such a configuration.

Committed to SVN TYPO3core trunk (revision 10013), branch TYPO3_4-4 (revision 10014) and branch TYPO3_4-3 (revision 10015).