The StringDelimitedUnparser is used both itself and as a base class of LiteralNilDelimitedEndOfDataUnparser.

This unparser still contains logic for performing pad/truncate.

This code will still execute, and won't cause errors all the time, because the new unparser mechanism for pad/fill will simply see a string that has already been padded, and so won't add any more. However, this code is redundant, and there is at least one known bug in it, which is
DFDL-1325.

This code should be removed so this code is not responsible for pad/fill, nor should it be checking that the length is not too long. nor should it be truncating.

See also DFDL-1595 about where the length-too-long check needs to be now.