TYPO3 Core

images in drag-n-drop listing are not displayed whenever the file extension is not lowercase.

example:
/folder/
a.gif
b.png
c.jpg
d.GIF <<-- won't be displayed in the RTE drag-n-drop listing.

it boils down to a bug in class.browse_links.php, where t3lib_div::inList('gif,jpeg,jpg,png',$fI['extension'])) is called without strtolower() on the file extension.

solution is simple: use strtolower when checking whether the file extension is in the list.

(issue imported from #M5189)