bug#16553: 24.3.50; `file-truename' returns a cons? (wrong-type-argument stringp (...))

[Eli Zaretskii]

> Date: Sat, 25 Jan 2014 15:09:11 -0800 (PST)
> From: Drew Adams <drew.adams@oracle.com>
> 
> The next thing I saw in the debugger was this bizarre call to
> `file-name-sans-extension':
> 
> Debugger entered--entering a function:
> * file-name-sans-extension((require . fit-frame))
> * #[514...]
> * apply(#[514...] (message-tab 
> "d:/Emacs-24-2014-01-23/share/emacs/24.3.50/lisp/gnus/message.el"))
> * help-fns--autoloaded-p(message-tab 
> "d:/Emacs-24-2014-01-23/share/emacs/24.3.50/lisp/gnus/message.el")
>   describe-function-1(message-tab)
>   describe-key("      " 1 nil)
>   call-interactively(describe-key nil nil)
>   command-execute(describe-key)

Isn't it possible that you have that weird cons cell in your
load-history?  help-fns--autoloaded-p does this:

    (while (and load-hist (not found))
      (and (caar load-hist)
           (equal (file-name-sans-extension (caar load-hist)) file)

So if some element in load-history is that cons cell, this code will
call file-name-sans-extension on that cons cell.