Don't fail, if filenames are too long, shorten them instead

[nibra]

Summary of Changes

The length of filenames is restricted to 250 characters, move_uploaded_files() already fails with length above 247 characters.(as stated in a comment in the PHP manual).

With this PR, filenames (i.e., the basename plus the extension) are shortend to 240 characters, if their length exceed that length with the File::makeSafe() method. The directory and the extension are preserved.

Changes affecting tests only:

• The HelperTest addresses example.org instead of joomla.org, which seems to be more reliable.

Testing Instructions

The change is covered by unit tests.
Call File::makeSafe() with a filename with more than 240 characters. The result should be a sanitised version of the filename with a maximum length of 240 characters.

Documentation Changes Required

Probably.

[HLeithner]

I think this should throw an exception and not silently change the input

[Llewellynvdm]

I would tend to agree with @HLeithner since the file name may be stored in the database, and unbeknown to the developer/user the mismatch exist.

Then filenames of that length is an edge-case and not that common, well at-least in my world.

[nibra]

Objection sustained!

[nibra]

Moved shortening to File::makeSafe() which is expected to sanitise the filename properly.