12.15.14 File encoding guesser improved

sys:guess-external-format (called by open for character file streams) no longer overrides any specified external format name that it is given (via the :external-format argument to open ).

Also sys:merge-ef-specs has been changed to merge the parameters only in cases where it can guarantee correctness.

See the LispWorks Reference Manual for details of both these functions.

LispWorks Release Notes and Installation Guide - 18 Mar 2008