Update language requirement for original files

[SvenLie]

Corrected the statement regarding the original file language requirement.

https://review.typo3.org/c/Packages/TYPO3.CMS/+/85447

[garvinhicking]

Please hang on here. I thino for v14 the plan was to ensure "locallang.xlf" files wilk be english.

Did you try if it all works properly also when using language domains?

I don't want to encourage this usage unless we're very certain.

I would like to invole Benni Mack for this, but he's not available for this at this time.

[garvinhicking]

See comment, let's wait for this

[linawolf]

Lets put this on draft until resolved

[rr-it]

Right now the fallback for e.g. de-AT is:
de-AT.locallang.xlf --> de.locallang.xlf --> en.locallang.xlf --> locallang.xlf
As 'en' and "default"/"base" are the default fallbacks.

As long as there is en in the default fallback chain, we can not really introduce the use of en.locallang.xlf.

[SvenLie]

Why is the fallback of de.locallang.xlf en.locallang.xlf?

Should be de.locallang.xlf -> locallang.xlf. That would be fine in my opinion.

[linawolf]

Once we have decided on the actual wording we will merge and backport #6340, closing this one so there is no discussion in two threads and no conflicting texts merged. Please move to the PR on main with your discussions everyone.