bug#13636: 24.3.50; tramp+ftp broken

[Eli Zaretskii <eliz@gnu.org>]

> From: Thierry Volpiatto <thierry.volpiatto@gmail.com>
> Date: Wed, 06 Feb 2013 17:47:17 +0100
> Cc: 13636@debbugs.gnu.org
> 
> >> Debugger entered--Lisp error: (wrong-type-argument stringp nil)
> >>   signal(wrong-type-argument (stringp nil))
> >>   byte-code("\301\b@\bA\"\207" [err signal] 3)
> >>   ange-ftp-hook-function(file-remote-p "/ftp:mafreebox.freebox.fr:" nil nil)
> >
> > Still not sufficient. I don't see where (stringp nil) is called.
> > "/ftp:mafreebox.freebox.fr:" is a string (obviously). The other
> > parameters of `file-remote-p' are optional, it is OK to be nil.
> >
> > What happens, if you eval in your *scratch* buffer
> >
> > (file-remote-p "/ftp:mafreebox.freebox.fr:" nil nil)
> Same error.
> 
> > What happens, if you move your ~/.netrc away (temporarily)?
> It is working when I remove .netrc
> (file-remote-p "/ftp:mafreebox.freebox.fr:")
> => "/ftp:mafreebox.freebox.fr:"
> 
> Here the entry in .netrc:
> 
> machine mafreebox.freebox.fr login freebox password xxxxx

Just run Emacs under GDB, put a breakpoint in wrong_type_argument, and
when it breaks, show the backtrace (including "xbacktrace").  That
should show enough for Michael to see the information he wants.