Emacs removes whitespaces at the end of lines

Emacs removes whitespaces at the end of lines

[F. Unglaub]

Hello,

I use emacs with mutt and slrn (post-mode) and noticed that
whitespaces at the end of lines are auto-removed. This leads to
problems, for example, with the signature delimiter "-- \n". In my
case it's reduced to "--\n" which certain newsreaders like tin
consider wrong.

Also those unused headers should have the trailing whitespace IIRC
(for example Summary, Keywords etc.).

Is there any setting that can circumvent this issue?

Regards.
--
"... the Mayo Clinic, named after its founder, Dr. Ted Clinic ..."
                -- Dave Barry

Re: Emacs removes whitespaces at the end of lines

[David Kastrup]

"F. Unglaub" <f.unglaub@gmail.com> writes:

> Hello,
>
> I use emacs with mutt and slrn (post-mode) and noticed that
> whitespaces at the end of lines are auto-removed. This leads to
> problems, for example, with the signature delimiter "-- \n". In my
> case it's reduced to "--\n" which certain newsreaders like tin
> consider wrong.
>
> Also those unused headers should have the trailing whitespace IIRC
> (for example Summary, Keywords etc.).
>
> Is there any setting that can circumvent this issue?

It is not the default, so you have something in your .emacs or other
customizations that does this.

-- 
David Kastrup

Re: Emacs removes whitespaces at the end of lines

[Tassilo Horn]

"F. Unglaub" <f.unglaub@gmail.com> writes:

Hi!

> I use emacs with mutt and slrn (post-mode) and noticed that
> whitespaces at the end of lines are auto-removed. This leads to
> problems, for example, with the signature delimiter "-- \n". In my
> case it's reduced to "--\n" which certain newsreaders like tin
> consider wrong.

All newsreaders should consider it wrong, cause it is, well, wrong. :-)

Back to the problem: Normally, emacs should not do that, so I guess
that's something you (or your sysadmin) configured.  Something like:

  (add-hook 'before-save-hook 'delete-trailing-whitespace)

So grep your ~/.emacs and the files in the site-lisp directory for
`delete-trailing-whitespace'.

Bye,
Tassilo

Re: Emacs removes whitespaces at the end of lines

[F. Unglaub]

On 2009-08-02, Tassilo Horn <tassilo@member.fsf.org> wrote:
> "F. Unglaub" <f.unglaub@gmail.com> writes:
>> I use emacs with mutt and slrn (post-mode) and noticed that
>> whitespaces at the end of lines are auto-removed. This leads to
>> problems, for example, with the signature delimiter "-- \n". In my
>> case it's reduced to "--\n" which certain newsreaders like tin
>> consider wrong.

[...]

> Back to the problem: Normally, emacs should not do that, so I guess
> that's something you (or your sysadmin) configured.  Something like:
>
>   (add-hook 'before-save-hook 'delete-trailing-whitespace)
>
> So grep your ~/.emacs and the files in the site-lisp directory for
> `delete-trailing-whitespace'.

I can only find delete-trailing-whitespace in my rails-mode.el
file. And I'm certain that I'm not using rails-mode for posting emails
and news.

Could there be anything besides the mentioned hook that could cause
this problem?

Regards.
--
Never lend your car to anyone to whom you have given birth.
                -- Erma Bombeck

Re: Emacs removes whitespaces at the end of lines

[Noah Slater]

On Sun, Aug 02, 2009 at 03:28:16PM +0200, F. Unglaub wrote:
> I use emacs with mutt and slrn (post-mode) and noticed that
> whitespaces at the end of lines are auto-removed. This leads to
> problems, for example, with the signature delimiter "-- \n". In my
> case it's reduced to "--\n" which certain newsreaders like tin
> consider wrong.

I was getting this too, and I came up with:

  (defun cleanup-buffer ()
    (unless (or (equal major-mode 'makefile-mode)
                (equal major-mode 'makefile-automake-mode)
                (equal major-mode 'makefile-gmake-mode))
      (untabify (point-min) (point-max)))
    (delete-trailing-whitespace)
    (when (equal major-mode 'post-mode)
      (save-excursion
        (goto-char (point-min))
      (while (re-search-forward "^--$" nil t) (replace-match "-- " nil nil)))))

  (add-hook 'write-file-hooks 'cleanup-buffer)

That should add the space back in as you save the file.

Best,

-- 
Noah Slater, http://tumbolia.org/nslater

Re: Emacs removes whitespaces at the end of lines

[Tassilo Horn]

"F. Unglaub" <f.unglaub@gmail.com> writes:

Hi!

>> Back to the problem: Normally, emacs should not do that, so I guess
>> that's something you (or your sysadmin) configured.  Something like:
>>
>>   (add-hook 'before-save-hook 'delete-trailing-whitespace)
>>
>> So grep your ~/.emacs and the files in the site-lisp directory for
>> `delete-trailing-whitespace'.
>
> I can only find delete-trailing-whitespace in my rails-mode.el
> file. And I'm certain that I'm not using rails-mode for posting emails
> and news.

Well, it could be that rails-mode adds that to some hook globally.  In
the worst case, then simply loading the mode would cause that behavior.

Please poste the relevant lines of rails-mode, then we'll see if they
are the culprit.

Bye,
Tassilo

Re: Emacs removes whitespaces at the end of lines

[F. Unglaub]

On 2009-08-02, Tassilo Horn <tassilo@member.fsf.org> wrote:
> "F. Unglaub" <f.unglaub@gmail.com> writes:
>
> Hi!
>
>>> Back to the problem: Normally, emacs should not do that, so I guess
>>> that's something you (or your sysadmin) configured.  Something like:
>>>
>>>   (add-hook 'before-save-hook 'delete-trailing-whitespace)
>>>
>>> So grep your ~/.emacs and the files in the site-lisp directory for
>>> `delete-trailing-whitespace'.
>>
>> I can only find delete-trailing-whitespace in my rails-mode.el
>> file. And I'm certain that I'm not using rails-mode for posting emails
>> and news.
>
> Well, it could be that rails-mode adds that to some hook globally.  In
> the worst case, then simply loading the mode would cause that behavior.

Looks like this is the case here. I removed rails-mode from my .emacs
and that seems to solve the problem for me.

> Please poste the relevant lines of rails-mode, then we'll see if they
> are the culprit.

Here are the relevant lines: (untabify-file.el)

(defun untabify-before-write ()
  "Strip all trailing whitespaces and untabify buffer before
save."
  (when (and (eq this-command 'save-buffer)
             (not (find nil
                        untabify-exclude-list
                        :if #'(lambda (r)
                                (typecase r
                                  (string (string-match r (buffer-name)))
                                  (symbol (eq major-mode r)))))))
    (save-excursion
      (untabify (point-min) (point-max))
      (delete-trailing-whitespace))))

(add-hook 'write-file-hooks 'untabify-before-write)


Regards.
-- 
Troubles are like babies; they only grow by nursing.

Re: Emacs removes whitespaces at the end of lines

[Anselm Helbig]

Hi!

At Mon, 3 Aug 2009 10:47:50 +0200,
"F. Unglaub" <f.unglaub@gmail.com> wrote:
> 
> On 2009-08-02, Tassilo Horn <tassilo@member.fsf.org> wrote:
> > "F. Unglaub" <f.unglaub@gmail.com> writes:
> >
> > Hi!
> >
> >>> Back to the problem: Normally, emacs should not do that, so I guess
> >>> that's something you (or your sysadmin) configured.  Something like:
> >>>
> >>>   (add-hook 'before-save-hook 'delete-trailing-whitespace)
> >>>
> >>> So grep your ~/.emacs and the files in the site-lisp directory for
> >>> `delete-trailing-whitespace'.
> >>
> >> I can only find delete-trailing-whitespace in my rails-mode.el
> >> file. And I'm certain that I'm not using rails-mode for posting emails
> >> and news.
> >
> > Well, it could be that rails-mode adds that to some hook globally.  In
> > the worst case, then simply loading the mode would cause that behavior.
> 
> Looks like this is the case here. I removed rails-mode from my .emacs
> and that seems to solve the problem for me.
> 
> > Please poste the relevant lines of rails-mode, then we'll see if they
> > are the culprit.
> 
> Here are the relevant lines: (untabify-file.el)
> 
> (defun untabify-before-write ()
>   "Strip all trailing whitespaces and untabify buffer before
> save."
>   (when (and (eq this-command 'save-buffer)
>              (not (find nil
>                         untabify-exclude-list
>                         :if #'(lambda (r)
>                                 (typecase r
>                                   (string (string-match r (buffer-name)))
>                                   (symbol (eq major-mode r)))))))
>     (save-excursion
>       (untabify (point-min) (point-max))
>       (delete-trailing-whitespace))))
> 
> (add-hook 'write-file-hooks 'untabify-before-write)

Yes, unfortunately emacs-rails behaves more like rails and not like a
well-behaved, humble emacs extension should: it just turns on a lot of
behavior, assuming that you'll probably like it. I'd rather turn stuff
on that I like than have to turn stuff off that comes into my way... 

If you want to keep emacs-rails and don't want to remove the line
containing the call to `add-hook', you can just remove the hook after
untabify-file is loaded:

  (eval-after-load "untabify-file"
    '(remove-hook 'write-file-hooks 'untabify-before-write))

HTH, 

Anselm


-- 
Anselm Helbig 
mailto:anselm.helbig+news2009@googlemail.com

Re: Emacs removes whitespaces at the end of lines

[F. Unglaub]

On 2009-08-03, Anselm Helbig <anselm.helbig+news2009@googlemail.com> wrote:
>> On 2009-08-02, Tassilo Horn <tassilo@member.fsf.org> wrote:
>> > "F. Unglaub" <f.unglaub@gmail.com> writes:
>> >
>> > Hi!
>> >
>> >>> Back to the problem: Normally, emacs should not do that, so I guess
>> >>> that's something you (or your sysadmin) configured.  Something like:
>> >>>
>> >>>   (add-hook 'before-save-hook 'delete-trailing-whitespace)
>> >>>
>> >>> So grep your ~/.emacs and the files in the site-lisp directory for
>> >>> `delete-trailing-whitespace'.
>> >>
>> >> I can only find delete-trailing-whitespace in my rails-mode.el
>> >> file. And I'm certain that I'm not using rails-mode for posting emails
>> >> and news.
>> >
>> > Well, it could be that rails-mode adds that to some hook globally.  In
>> > the worst case, then simply loading the mode would cause that behavior.
>> 
>> Looks like this is the case here. I removed rails-mode from my .emacs
>> and that seems to solve the problem for me.
>> 
>> > Please poste the relevant lines of rails-mode, then we'll see if they
>> > are the culprit.
>> 
>> Here are the relevant lines: (untabify-file.el)
>> 
>> (defun untabify-before-write ()
>>   "Strip all trailing whitespaces and untabify buffer before
>> save."
>>   (when (and (eq this-command 'save-buffer)
>>              (not (find nil
>>                         untabify-exclude-list
>>                         :if #'(lambda (r)
>>                                 (typecase r
>>                                   (string (string-match r (buffer-name)))
>>                                   (symbol (eq major-mode r)))))))
>>     (save-excursion
>>       (untabify (point-min) (point-max))
>>       (delete-trailing-whitespace))))
>> 
>> (add-hook 'write-file-hooks 'untabify-before-write)
>
> Yes, unfortunately emacs-rails behaves more like rails and not like a
> well-behaved, humble emacs extension should: it just turns on a lot of
> behavior, assuming that you'll probably like it. I'd rather turn stuff
> on that I like than have to turn stuff off that comes into my way... 
>
> If you want to keep emacs-rails and don't want to remove the line
> containing the call to `add-hook', you can just remove the hook after
> untabify-file is loaded:
>
>   (eval-after-load "untabify-file"
>     '(remove-hook 'write-file-hooks 'untabify-before-write))

Thanks a lot, that did the trick.

Regards, Florian.
-- 
What we need is either less corruption, or more chance to participate in it.

Re: Emacs removes whitespaces at the end of lines

[Tassilo Horn]

Anselm Helbig <anselm.helbig+news2009@googlemail.com> writes:

Hi!

>> > Please poste the relevant lines of rails-mode, then we'll see if
>> > they are the culprit.
>> 
>> Here are the relevant lines: (untabify-file.el)
>> 
>> [...]
>> 
>> (add-hook 'write-file-hooks 'untabify-before-write)

The right approach (if it's really a convention for rails code) would be
to call

   (add-hook 'write-file-hooks 'untabify-before-write nil t)

inside the `rails-mode' function.  The last parameter to `add-hook'
makes this hook buffer-local, so the untabify function would only be run
when saving a file that is in rails-mode.

> Yes, unfortunately emacs-rails behaves more like rails and not like a
> well-behaved, humble emacs extension should: it just turns on a lot of
> behavior, assuming that you'll probably like it.

I think you (or F. Unglaub) should send a bug report to the rails-mode
devs.  Modes must not change global settings.

> If you want to keep emacs-rails and don't want to remove the line
> containing the call to `add-hook', you can just remove the hook after
> untabify-file is loaded:
>
>   (eval-after-load "untabify-file"
>     '(remove-hook 'write-file-hooks 'untabify-before-write))

Yes, that's a workaround.

Bye,
Tassilo