Buglette & Fix for checkrmall in 4.0.2

Buglette & Fix for checkrmall in 4.0.2

[Stefan Dalibor]

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Hi,
just in case nobody else has been stumbled into this: 4.0.2 segfaults
in checkrmall() (under OpenLinux 3.1, i.e. Linux 2.4.* with glibc 2.2.1
and 2.2.4) when executing the following function:

function www {
	typeset netscapefiles="{lock,plugin-list*,history*,*cache/*,archive/*,*.db,abook.nab,registry,summary*,custom.dic}" \
		nsmaildir=$HOME/nsmail
	(	
		if [ -z "$DISPLAY" -a "$KPSYSTYPE" = 'i86linux' ]; then
			# Fire up X and start Mozilla from Linux text console:
			startx netscape "$@"
		else
			netscape "$@"
		fi
		# This crashes zsh-4.0.2 if unpatched:
		eval command rm -fr $HOME/.netscape/$netscapefiles /tmp/ndebug
		[ -d $nsmaildir ] && rmdir $nsmaildir
	) &
}

This is due to checkrmall() calling fprintf() with a NULL file ptr in
shout.

Please find attached the dumbest possible patch... it prevents the crash,
but I didn't investigate on wether it is the appropriate place for a
fix (should Zsh recognize that it's useless to call checkrmall() when
running in the background in the first place?  Is the NULL file ptr a
bug in itself?).

Cheers,
Stefan

P.S.: If you have any further questions, please set me on CC (I'm only on
      the Zsh announce list)
--
Dr.Ing. Stefan Dalibor <scd@caldera.de>

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Re: Buglette & Fix for checkrmall in 4.0.2

[Bart Schaefer]

On Oct 15,  1:32pm, Stefan Dalibor wrote:
}
} just in case nobody else has been stumbled into this: 4.0.2 segfaults
} in checkrmall() (under OpenLinux 3.1, i.e. Linux 2.4.* with glibc 2.2.1
} and 2.2.4) when executing the following function:
} 
    [a call to rm in a backgrounded subshell]

This raises the question of whether a backgrounded subshell should still
have the INTERACTIVE option set.

-- 
Bart Schaefer                                 Brass Lantern Enterprises
http://www.well.com/user/barts              http://www.brasslantern.com

Zsh: http://www.zsh.org | PHPerl Project: http://phperl.sourceforge.net   

Re: Buglette & Fix for checkrmall in 4.0.2

[Bart Schaefer]

On Oct 15,  1:32pm, Stefan Dalibor wrote:
}
} This is due to checkrmall() calling fprintf() with a NULL file ptr in
} shout.
} 
} (Is the NULL file ptr a bug in itself?).

That's what I'm wondering now, because I can't immediately see any reason
why this would be different in 3.0.8, yet it does work in 3.0.8.

-- 
Bart Schaefer                                 Brass Lantern Enterprises
http://www.well.com/user/barts              http://www.brasslantern.com

Zsh: http://www.zsh.org | PHPerl Project: http://phperl.sourceforge.net   

Re: Buglette & Fix for checkrmall in 4.0.2

[Peter Stephenson]

Bart Schaefer wrote:
> This raises the question of whether a backgrounded subshell should still
> have the INTERACTIVE option set.

Yes, we already unset MONITOR and USEZLE.  I remember wondering about this
some time ago and not coming to a definite conclusion.  On the whole I
think it's a good idea (we certainly don't any terminal setup stuff to run
in the subshell) but that doesn't mean it won't break something.

-- 
Peter Stephenson <pws@csr.com>                  Software Engineer
CSR Ltd., Science Park, Milton Road,
Cambridge, CB4 0WH, UK                          Tel: +44 (0)1223 392070


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Re: Buglette & Fix for checkrmall in 4.0.2

[Borsenkow Andrej]

On Пнд, 2001-10-15 at 21:07, Peter Stephenson wrote:
> Bart Schaefer wrote:
> > This raises the question of whether a backgrounded subshell should still
> > have the INTERACTIVE option set.
> 
> Yes, we already unset MONITOR and USEZLE.  I remember wondering about this
> some time ago and not coming to a definite conclusion.  On the whole I
> think it's a good idea (we certainly don't any terminal setup stuff to run
> in the subshell) but that doesn't mean it won't break something.
> 

I have very vague recollection that I complained about this once and
somebody (Bart? Peter?) gave me valid reasons why it should not be
unset. But may be it was another option,

-andrej

Re: Buglette & Fix for checkrmall in 4.0.2

[Bart Schaefer]

On Oct 15, 10:13pm, Borsenkow Andrej wrote:
> Subject: Re: Buglette & Fix for checkrmall in 4.0.2
> On ðÎÄ, 2001-10-15 at 21:07, Peter Stephenson wrote:
> > Bart Schaefer wrote:
> > > This raises the question of whether a backgrounded subshell should still
> > > have the INTERACTIVE option set.
> 
> I have very vague recollection that I complained about this once and
> somebody (Bart? Peter?) gave me valid reasons why it should not be
> unset. But may be it was another option,

There are reasons to leave interactive set in a subshell.  I'm not sure
there are reasons to leave it set in a *backgrounded* subshell.  Perhaps
it's too difficult to tell whether a subshell is being backgrounded?

Re: Buglette & Fix for checkrmall in 4.0.2

[Bart Schaefer]

On Oct 15,  1:32pm, Stefan Dalibor wrote:
}
} just in case nobody else has been stumbled into this: 4.0.2 segfaults
} 
} This is due to checkrmall() calling fprintf() with a NULL file ptr in
} shout.

After a little further checking, this appears to be due to my patch in
zsh-users/3358, and therefore Stefan's fix is sufficient.

-- 
Bart Schaefer                                 Brass Lantern Enterprises
http://www.well.com/user/barts              http://www.brasslantern.com

Zsh: http://www.zsh.org | PHPerl Project: http://phperl.sourceforge.net