[TYPO3-dev] Records not translated properly when "sys_language_uid" is used as "type" field in TCA

[Roland]

hi everybody,

for some tables of my extension i would like to set "sys_language_uid" 
as the type field to show different table fields for different languages 
in TYPO3 BE.

unfortunatelly when clicking on a language flag in TYPO3 list module to 
translate a record to another language the field "sys_language_uid" is 
not filled with the UID of the language. the field "l10n_parent" is 
filled correctly.

could this be a bug/missing feature?

if so: can someone please tell me where to look that i can try to fix 
that in TYPO3 core an push it to gerrit? thanks.

kind regards

roland