bug#8964: 24.0.50; `find-file' triggers the debugger when called with a nonexistent remote file

bug#8964: 24.0.50; `find-file' triggers the debugger when called with a nonexistent remote file

[Dani Moncayo]

Package: emacs
Version: 24.0.50

From "emacs -Q":
1. Eval this, literally: (find-file "/user@host:/file")
2. Give any random password (for user@host).

Then, the a debugger window pops up, with this text:

  Debugger entered--Lisp error: (ftp-error #("FTP Error: OPEN request
failed: Unknown host host." 32 50 (fontified nil front-sticky (field
inhibit-line-move-field-capture) rear-nonsticky t field output
inhibit-line-move-field-capture t)))
    signal(ftp-error (#("FTP Error: OPEN request failed: Unknown host
host." 32 50 (fontified nil front-sticky (field
inhibit-line-move-field-capture) rear-nonsticky t field output
inhibit-line-move-field-capture t))))
    byte-code("\b\203\x13


If the host is unknown, it should be notified with a message in the
minibuffer (as happens if you do it interactively with C-x C-f), but
not by triggering the debugger.


In GNU Emacs 24.0.50.1 (i386-mingw-nt5.1.2600)
 of 2011-06-27 on 3249CTO
Windowing system distributor `Microsoft Corp.', version 5.1.2600
configured using `configure --with-gcc (4.5) --no-opt --cflags
-Ic:/build/include'


-- 
Dani Moncayo

bug#8964: 24.0.50; `find-file' triggers the debugger when called with a nonexistent remote file

[Dani Moncayo]

BTW, he same happens when user@host is OK, but the _path_ to the file
is wrong.  In this case, the debugger window shows something like
this:

   Debugger entered--Lisp error: (ftp-error #("FTP Error: DIR failed:
550 /home/fac19/PREVTEC/ptbsgpmx.4exs/: No such file or directory." 23
89 (fontified nil front-sticky (field inhibit-line-move-field-capture)
rear-nonsticky t field output inhibit-line-move-field-capture t)))
     signal(ftp-error (#("FTP Error: DIR failed: 550
/home/fac19/PREVTEC/ptbsgpmx.4exs/: No such file or directory." 23 89
(fontified nil front-sticky (field inhibit-line-move-field-capture)
rear-nonsticky t field output inhibit-line-move-field-capture t))))
     byte-code("\b\203\x13


-- 
Dani Moncayo

bug#8964: 24.0.50; `find-file' triggers the debugger when called with a nonexistent remote file

[Eli Zaretskii]

> Date: Thu, 30 Jun 2011 11:40:49 +0200
> From: Dani Moncayo <dmoncayo@gmail.com>
> 
> >From "emacs -Q":
> 1. Eval this, literally: (find-file "/user@host:/file")
> 2. Give any random password (for user@host).
> 
> Then, the a debugger window pops up, with this text:
> 
>   Debugger entered--Lisp error: (ftp-error #("FTP Error: OPEN request
> failed: Unknown host host." 32 50 (fontified nil front-sticky (field

Do you eval this in the *scratch* buffer?  If so, this is a feature:
the Lisp interaction mode in *scratch* sets up things so that
debug-on-error is non-nil, which causes every call to `error' to enter
the debugger.  Normally, `error' just aborts the current command and
displays an error message.

If you don't eval in *scratch*, please tell exactly how you do it.

bug#8964: 24.0.50; `find-file' triggers the debugger when called with a nonexistent remote file

[Dani Moncayo]

> If you don't eval in *scratch*, please tell exactly how you do it.

I've just tried and been able to reproduce the problem from these modes:
 - "Lisp Interaction" (*scratch* buffer)
 - "Emacs-Lisp" (visiting a ".el" file)
 - "Fundamental" (a brand new buffer)
 - "Text mode"


-- 
Dani Moncayo

bug#8964: 24.0.50; `find-file' triggers the debugger when called with a nonexistent remote file

[Eli Zaretskii]

> Date: Thu, 30 Jun 2011 14:39:35 +0200
> From: Dani Moncayo <dmoncayo@gmail.com>
> Cc: 8964@debbugs.gnu.org
> 
> > If you don't eval in *scratch*, please tell exactly how you do it.
> 
> I've just tried and been able to reproduce the problem from these modes:
>  - "Lisp Interaction" (*scratch* buffer)
>  - "Emacs-Lisp" (visiting a ".el" file)
>  - "Fundamental" (a brand new buffer)
>  - "Text mode"

Was debug-on-error set to non-nil?  If so, this is intended behavior
of ange-ftp.

bug#8964: 24.0.50; `find-file' triggers the debugger when called with a nonexistent remote file

[Dani Moncayo]

> Was debug-on-error set to non-nil?  If so, this is intended behavior
> of ange-ftp.

C-h v debug-on-error gives:
  debug-on-error is a variable defined in `C source code'.
  Its value is nil


-- 
Dani Moncayo

bug#8964: 24.0.50; `find-file' triggers the debugger when called with a nonexistent remote file

[Eli Zaretskii]

> Date: Thu, 30 Jun 2011 15:19:11 +0200
> From: Dani Moncayo <dmoncayo@gmail.com>
> Cc: 8964@debbugs.gnu.org
> 
> > Was debug-on-error set to non-nil?  If so, this is intended behavior
> > of ange-ftp.
> 
> C-h v debug-on-error gives:
>   debug-on-error is a variable defined in `C source code'.
>   Its value is nil

Try "M-: debug-on-error RET".

bug#8964: 24.0.50; `find-file' triggers the debugger when called with a nonexistent remote file

[Dani Moncayo]

> Try "M-: debug-on-error RET".

Gives `t'.


How is it possible?  I.e., why "C-h v" gives a different value than "M-:"?

And why "M-: debug-on-error RET" returns `t' even after doing (setq
debug-on-error nil)?

-- 
Dani Moncayo

bug#8964: 24.0.50; `find-file' triggers the debugger when called with a nonexistent remote file

[Glenn Morris]

Dani Moncayo wrote:

> How is it possible?  I.e., why "C-h v" gives a different value than "M-:"?
>
> And why "M-: debug-on-error RET" returns `t' even after doing (setq
> debug-on-error nil)?

Because of eval-expression-debug-on-error, I think.

bug#8964: 24.0.50; `find-file' triggers the debugger when called with a nonexistent remote file

[Eli Zaretskii]

> From: Glenn Morris <rgm@gnu.org>
> Cc: Eli Zaretskii <eliz@gnu.org>,  8964@debbugs.gnu.org
> Date: Thu, 30 Jun 2011 14:00:03 -0400
> 
> Dani Moncayo wrote:
> 
> > How is it possible?  I.e., why "C-h v" gives a different value than "M-:"?
> >
> > And why "M-: debug-on-error RET" returns `t' even after doing (setq
> > debug-on-error nil)?
> 
> Because of eval-expression-debug-on-error, I think.

Of course.  And that's also the reason why evaluating something like
`(find-file "foo")' will run with debug-on-error set non-nil, and
that's why ange-ftp enters the debugger when it signals an error.

IOW, not a bug, like I said.

bug#8964: 24.0.50; `find-file' triggers the debugger when called with a nonexistent remote file

[Dani Moncayo]

>> > How is it possible?  I.e., why "C-h v" gives a different value than "M-:"?
>> >
>> > And why "M-: debug-on-error RET" returns `t' even after doing (setq
>> > debug-on-error nil)?
>>
>> Because of eval-expression-debug-on-error, I think.
>
> Of course.  And that's also the reason why evaluating something like
> `(find-file "foo")' will run with debug-on-error set non-nil, and
> that's why ange-ftp enters the debugger when it signals an error.
>
> IOW, not a bug, like I said.

Eli, Glenn, thanks for your explanations.  I understand it now.

You can close this bug.

-- 
Dani Moncayo

bug#8964: 24.0.50; `find-file' triggers the debugger when called with a nonexistent remote file

[Eli Zaretskii]

> Date: Thu, 30 Jun 2011 20:52:37 +0200
> From: Dani Moncayo <dmoncayo@gmail.com>
> Cc: Glenn Morris <rgm@gnu.org>, 8964@debbugs.gnu.org
> 
> Eli, Glenn, thanks for your explanations.  I understand it now.
> 
> You can close this bug.

Done.

bug#8964: 24.0.50; `find-file' triggers the debugger when called with a nonexistent remote file

[Lars Magne Ingebrigtsen]

Eli Zaretskii <eliz@gnu.org> writes:

>> 1. Eval this, literally: (find-file "/user@host:/file")
>> 2. Give any random password (for user@host).

For me, this fails, too, but by hanging until I `C-g'.

If I look in the "*ftp user...*" buffer, I then find:

---
ftp> open host
ftp: host: Name or service not knownftp> 
---

Which sounds like a totally unrelated issue.  :-)

-- 
(domestic pets only, the antidote for overdose, milk.)
  bloggy blog http://lars.ingebrigtsen.no/