Incorrect type error in code involving REPLACE

[Paul F. Dietz]

(defun bug312 ()
  (let* ((params
           (list (coerce '(1 2 3 4) 'simple-vector)
                 (list #c(-1.0d0 7.0d0))))
         (lam
           `(lambda (p1 p2)
              (declare (type
                        (and
                         cons
                         (or
                          (eql ,(cadr params))
                          (eql (#c(3.0d0 5.0d0) 1/2))))
                        p2))
              (replace p1
                       (the (cons (eql ,(caadr params)) t) p2)))))
    (apply (compile nil lam) params)))

(bug312) ==>

The value
  (#C(3.0d0 5.0d0) 1/2)
is not of type
  (CONS (MEMBER #C(-1.0d0 7.0d0)) T)
   [Condition of type TYPE-ERROR]

This may be a bug in type simplification. Weirdly, the bug goes away if the complex numbers are #C(1.0 2.0d0) and #C(3.0d0 4.0d0).

x86-64, "2.4.0.223-aaed94aaf"

[Stas Boukarev (stassats)]

(type-union (specifier-type '(cons (complex (double-float 3.0d0 5.0d0))))
            (specifier-type '(cons (complex (double-float -1.0d0 7.0d0)) null)))

produces some nonsense:

#<UNION-TYPE (OR (CONS (COMPLEX (DOUBLE-FLOAT 3.0d0 5.0d0)) T)
                 (CONS (OR (COMPLEX (DOUBLE-FLOAT -1.0d0 (3.0d0))) (COMPLEX (DOUBLE-FLOAT (5.0d0) 7.0d0))) NULL))>