glib:key-file-locale-for-key (keyfile group key &optional locale)

keyfile -- a g:key-file instance
group -- a string for the group name
key -- a string for the key
locale -- a string for the locale identifier

The string with the locale from the file, or nil if the key was not found or the entry in the file was untranslated.

Returns the actual locale which the result of the g:key-file-locale-string or g:key-file-locale-string-list function came from.

If calling the g:key-file-locale-string or g:key-file-locale-string-list function with exactly the same keyfile, group, key and locale, the result of those functions will have originally been tagged with the locale that is the result of this function.