• Paul Eggert's avatar
    Fix ambiguity in nil DST flag · 0bec0644
    Paul Eggert authored
    Formerly nil meant both that DST was not in effect and that
    the DST flag was unknown, and different functions interpreted
    the flag differently.  Now the meaning is consistently nil for
    DST not in effect, and -1 for DST flag not known.
    * doc/lispref/os.texi (Time Conversion): The DST slot is
    now three-valued, not two-.
    * doc/misc/emacs-mime.texi (time-date): Adjust to new behavior.
    * etc/NEWS: Mention this.
    * lisp/calendar/parse-time.el (parse-time-string):
    * src/editfns.c (Fdecode_time):
    Return -1 for unknown DST flag.
    * test/lisp/calendar/parse-time-tests.el (parse-time-tests):
    Adjust tests to match new behavior, and add a new
    test for nil vs -1.
editfns.c 179 KB