Subject: bug#6187: Wrong type argument: number-of-marker-p, nil

From: Christophe TROESTLER <[email-masked]>
Date: Sat, 13 Aug 2011 00:58:25 +0200 (CEST)

The same goes for (unencodable-char-position 0 2 'latin-1 1 " Ẽ ")
— it returns “nil” instead of “(1)”.

We are not the only ones to encounter this bug :
http://lists.gnu.org/archive/html/emacs-devel/2010-04/msg00608.html