invisible&after-string of overlay

[Kenichi Handa]

I've got a bug report about the combination of invisible and
after-string properties of an overlay.

Please evaluate this in *scratch* buffer.

(save-excursion
  (goto-char (point-min))
  (insert "123\n")
  (let ((o1 (make-overlay 1 2))
        (o2 (make-overlay 2 3)))
    (overlay-put o1 'invisible t)
    (overlay-put o1 'evaporate t)
    (overlay-put o1 'after-string "A")
    (overlay-put o2 'invisible t)
    (overlay-put o2 'evaporate t)
    (overlay-put o2 'after-string "B")))

Emacs 21.3 and HEAD displays "B3" in the first line, but
Emacs 20.7 displays "AB3".  It seems that the latter is
correct.  Is it a feature change or a bug?

---
Ken'ichi HANDA
address@hidden