bug#24912: 25.1.50; Byte compiler generates incorrect code when second &optional is used

[Philipp Stephani]

Philipp Stephani <p.stephani2@gmail.com> schrieb am Mi., 9. Nov. 2016 um 22:11 Uhr:

emacs -Q

In *scratch*, evaluate:

(funcall
 (let ((lexical-binding t))
   (byte-compile
    (lambda (&optional a b)
      (list a b))))
 'a 'b)

Result is (a b), as expected.  Now evaluate

(funcall
 (let ((lexical-binding t))
   (byte-compile
    (lambda (&optional a &optional b)
      (list a b))))
 'a 'b)

Result is (b nil).

Emacs should either generate correct code in both cases, or signal an
error in the latter case.

Fixed with commit  0d913da15c094bf596dd685acecf3438228c15cf.