bug#4324: 23.1.50; footenote: Wrong type argument: number-or-marker-p, nil

Please describe exactly what actions triggered the bug
and the precise symptoms of the bug:

To reproduce:

1. C-x m
2. M-x footnote-mode
3. C-c ! g

error:

Wrong type argument: number-or-marker-p, nil

Patch:

diff -c -L a/footnote.el.gz~ -L b/footnote.el.gz
*** a/footnote.el.gz~
--- b/footnote.el.gz
***************
*** 566,571 ****
--- 566,572 ----
                   (Footnote-narrow-to-footnotes)
                   (and (>= old-point (point-min))
                        (<= old-point (point-max))))))
+              footnote-text-marker-alist
             (>= (point) (cdar footnote-text-marker-alist)))
      (let ((i 1)
          alist-txt rc)


Leo