Problem with Coding System Detection

In XEmacs 21.0 "20 minutes to Nikko" [Lucid] (i586-pc-linux, Mule) of Sun Jul 18 1999 on turing configured using `configure --error-checking=none --with-png=yes --with-mule=yes' Please describe exactly what actions triggered the bug and the precise symptoms of the bug: I cannot read files in /var/spool/mail. The reason is that find-file-coding-system-for-read-from-filename is picking up the function convert-mbox-coding-system from file-coding-system-alist and then calling it with the wrong arguments: ;; codesys set to convert-mbox-coding-system (funcall codesys 'insert-file-contents filename) -versus- (defun convert-mbox-coding-system (filename visit start end) -- Alastair