TYPO3 Core

I have a 6.2 installation with some files with uppercase file extensions, e. g. 'myimage.JPG'. These files can be uploaded to the file list within the backend module without problems. But when I try to insert such an image in a textpic-element, the element browser doesn't show the files with uppercase file extensions. Only files with lowercased file extensions are shown.

In elements with an existing file reference (to a file with uppercased file extension), the reference gets deleted, after the element is saved. The error message is always like this: "1: Attempt to modify record '34537' (sys_file_reference:34537) without permission. Or non-existing page."

I tracked it down to this change:
https://review.typo3.org/#/c/26520/

Before this change everything works as expected. When applying it, the above described behaviour is there.