TYPO3 Core

• Image a record that only exists in language 1.
• Fallback is 2 -> 1 -> 0
• Usually in the core records for IN (0, -1) are fetched and then overlays performed.
• In some cases also the current language is fetched (2 here) because there might be records which only exist in 2 and have no 0.

What we currently miss in various places are records that only exist in 1 (more general: only in languages inside the fallback-chain, not existing in 0 or the current language).

This turned up during the review of https://review.typo3.org/23905 but is imho a too general problem in various areas of the core as to fix it just in that one patch. We might need some tool-function to create a proper condition (like with enableFields or so).