CONCATENATE computes incorrect result on string with declaration, fill pointer

[Paul F. Dietz]

Please note how fill pointers and string types interact.

(typep (make-array '(1) :element-type 'character :fill-pointer 0) '(string 1)) ==> true

So:

(defun f301 (p2 p3)
  (declare (optimize (speed 2))
           (type (string 1) p3))
  (concatenate 'string p2 p3))

(f301 nil (make-array '(1) :element-type 'character :fill-pointer 0)) ==> "^@"

However:

(concatenate 'string nil (make-array '(1) :element-type 'character :fill-pointer 0)) ==> ""

[Stas Boukarev (stassats)]

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