DESTROY clobbers $@ in a eval {}

[p5pRT]

Migrated from rt.perl.org#123773 (status was 'resolved')

Searchable as RT123773$

[p5pRT]

From @FGasper

Created by @FGasper

===============
package Trouble;

sub new { bless [] }

sub DESTROY { $@​ = 'Bad things if this prints!' };

package main;

eval {
  my $baddie = Trouble->new();

  sub {
  $baddie;
  die 'This should print.';
  }->();
};
my $err = $@​;
print "From Perl $^V​: $err";

The above prints​:

From Perl v5.14.4​: Bad things if this prints!

Looks like the closure is holding onto a reference to $baddie for too long.

I suspect that this is related to #123738.

Perl Info

Flags:
    category=core
    severity=medium

Site configuration information for perl 5.14.4:

Configured by cPanel at Tue Dec 16 16:26:36 CST 2014.

Summary of my perl5 (revision 5 version 14 subversion 4) configuration:
   
  Platform:
    osname=linux, osvers=2.6.32-358.23.2.el6.i686, archname=i386-linux-64int
    uname='linux rpmb-32-centos-6 2.6.32-358.23.2.el6.i686 #1 smp wed oct 16 17:21:31 utc 2013 i686 i686 i386 gnulinux '
    config_args='-des -Dusedevel -Darchname=i386-linux-64int -Dcc=/usr/bin/gcc -Dcpp=/usr/bin/cpp -DDEBUGGING=none -Doptimize=-Os -Dusemymalloc=n -Duseshrplib -Duselargefiles=yes -Duseposix=true -Dhint=recommended -Duseperlio=yes -Dccflags=-I/usr/local/cpanel/3rdparty/perl/514/include -L/usr/local/cpanel/3rdparty/perl/514/lib -I/usr/local/cpanel/3rdparty/include -L/usr/local/cpanel/3rdparty/lib -DAPPLLIB_EXP="/usr/local/cpanel" -Dcppflags=-I/usr/local/cpanel/3rdparty/perl/514/include -L/usr/local/cpanel/3rdparty/perl/514/lib -I/usr/local/cpanel/3rdparty/include -L/usr/local/cpanel/3rdparty/lib -Dldflags=-Wl,-rpath -Wl,/usr/local/cpanel/3rdparty/perl/514/lib -L/usr/local/cpanel/3rdparty/perl/514/lib -L/usr/local/cpanel/3rdparty/lib -Dprefix=/usr/local/cpanel/3rdparty/perl/514 -Dsiteprefix=/opt/cpanel/perl5/514 -Dsitebin=/opt/cpanel/perl5/514/bin -Dsitelib=/opt/cpanel/perl5/514/site_lib -Dusevendorprefix=true -Dvendorbin=/usr/local/cpanel/3rdparty/perl/514/bin -Dvendorprefix=/usr/local/cpanel/3rdparty/perl/514/lib/perl5 -Dvendorlib=/usr/local/cpanel/3rdparty/perl/514/lib/perl5/cpanel_lib -Dprivlib=/usr/local/cpanel/3rdparty/perl/514/lib/perl5/5.14.4 -Dman1dir=none -Dman3dir=none -Dscriptdir=/usr/local/cpanel/3rdparty/perl/514/bin -Dscriptdirexp=/usr/local/cpanel/3rdparty/perl/514/bin -Dsiteman1dir=none -Dsiteman3dir=none -Dinstallman1dir=none -Dversiononly=no -Dinstallusrbinperl=no -Dcf_by=cPanel -Dmyhostname=localhost -Dperladmin=root@localhost -Dcf_email=support@cpanel.net -Di_dbm=/usr/local/cpanel/3rdparty/include -Di_gdbm=/usr/local/cpanel/3rdparty/include -Di_ndbm=/usr/local/cpanel/3rdparty/include -Ud_dosuid -Uuserelocatableinc -Umad -Uusethreads -Uusemultiplicity -Uusesocks -Uuselongdouble -Ui_db -Aldflags=-L/usr/local/cpanel/3rdparty/perl/514/lib -L/usr/local/cpanel/3rdparty/lib -L/usr/lib -L/lib -lgdbm -Dlocincpth=/usr/local/cpanel/3rdparty/perl/514/include /usr/local/cpanel/3rdparty/include /usr/local/include  -Duse64bitint -Uuse64bitall -Acflags=-fPIC -DPIC -m32 -I/usr/local/cpanel/3rdparty/perl/514/include -I/usr/local/cpanel/3rdparty/include -Dlibpth=/usr/local/cpanel/3rdparty/perl/514/lib /usr/local/cpanel/3rdparty/lib /usr/local/lib /lib /usr/lib '
    hint=recommended, useposix=true, d_sigaction=define
    useithreads=undef, usemultiplicity=undef
    useperlio=define, d_sfio=undef, uselargefiles=define, usesocks=undef
    use64bitint=define, use64bitall=undef, uselongdouble=undef
    usemymalloc=n, bincompat5005=undef
  Compiler:
    cc='/usr/bin/gcc', ccflags ='-I/usr/local/cpanel/3rdparty/perl/514/include -L/usr/local/cpanel/3rdparty/perl/514/lib -I/usr/local/cpanel/3rdparty/include -L/usr/local/cpanel/3rdparty/lib -DAPPLLIB_EXP="/usr/local/cpanel" -fno-strict-aliasing -pipe -fstack-protector -I/usr/local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64',
    optimize='-Os',
    cppflags='-I/usr/local/cpanel/3rdparty/perl/514/include -L/usr/local/cpanel/3rdparty/perl/514/lib -I/usr/local/cpanel/3rdparty/include -L/usr/local/cpanel/3rdparty/lib -I/usr/local/cpanel/3rdparty/perl/514/include -L/usr/local/cpanel/3rdparty/perl/514/lib -I/usr/local/cpanel/3rdparty/include -L/usr/local/cpanel/3rdparty/lib -DAPPLLIB_EXP="/usr/local/cpanel" -fno-strict-aliasing -pipe -fstack-protector -I/usr/local/include'
    ccversion='', gccversion='4.4.7 20120313 (Red Hat 4.4.7-3)', gccosandvers=''
    intsize=4, longsize=4, ptrsize=4, doublesize=8, byteorder=12345678
    d_longlong=define, longlongsize=8, d_longdbl=define, longdblsize=12
    ivtype='long long', ivsize=8, nvtype='double', nvsize=8, Off_t='off_t', lseeksize=8
    alignbytes=4, prototype=define
  Linker and Libraries:
    ld='/usr/bin/gcc', ldflags ='-Wl,-rpath -Wl,/usr/local/cpanel/3rdparty/perl/514/lib -L/usr/local/cpanel/3rdparty/perl/514/lib -L/usr/local/cpanel/3rdparty/lib -L/usr/local/cpanel/3rdparty/perl/514/lib -L/usr/local/cpanel/3rdparty/lib -L/usr/lib -L/lib -lgdbm -fstack-protector -L/usr/local/lib'
    libpth=/usr/local/lib /lib /usr/lib
    libs=-lnsl -lgdbm -ldb -ldl -lm -lcrypt -lutil -lc
    perllibs=-lnsl -ldl -lm -lcrypt -lutil -lc
    libc=/lib/libc-2.12.so, so=so, useshrplib=true, libperl=libperl.so
    gnulibc_version='2.12'
  Dynamic Linking:
    dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags='-Wl,-E -Wl,-rpath,/usr/local/cpanel/3rdparty/perl/514/lib/perl5/5.14.4/i386-linux-64int/CORE'
    cccdlflags='-fPIC', lddlflags='-shared -Os -L/usr/local/cpanel/3rdparty/perl/514/lib -L/usr/local/cpanel/3rdparty/lib -L/usr/lib -L/lib -L/usr/local/lib -fstack-protector'

Locally applied patches:
    cPanel patches
    cPanel INC path changes
    Disabled some unstable tests on a kvm build server
    Cherry pick of 49498ca from p5p (RT 113514)
    Remove improper use of each() in B::walksymtable (5cc8528c90)


@INC for perl 5.14.4:
    /usr/local/cpanel
    /usr/local/cpanel
    /usr/local/cpanel/3rdparty/perl/514/lib/perl5/cpanel_lib/i386-linux-64int
    /usr/local/cpanel/3rdparty/perl/514/lib/perl5/cpanel_lib
    /usr/local/cpanel/3rdparty/perl/514/lib/perl5/5.14.4/i386-linux-64int
    /usr/local/cpanel/3rdparty/perl/514/lib/perl5/5.14.4
    /opt/cpanel/perl5/514/site_lib/i386-linux-64int
    /opt/cpanel/perl5/514/site_lib
    .


Environment for perl 5.14.4:
    HOME=/root
    LANG=en_US.UTF-8
    LANGUAGE (unset)
    LD_LIBRARY_PATH (unset)
    LOGDIR (unset)
    PATH=/root/.opt/bin:/usr/local/cpanel/3rdparty/perl/514/bin:/usr/local/cpanel/3rdparty/bin:/usr/local/cpanel/3rdparty/node/bin:/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin
    PERL5LIB=/usr/local/cpanel
    PERL_BADLANG (unset)
    SHELL=/bin/bash

[p5pRT]

From @jkeenan

On Mon, 09 Feb 2015 20​:31​:11 GMT, felipe@​felipegasper.com wrote​:

This is a bug report for perl from felipe@​felipegasper.com,
generated with the help of perlbug 1.39 running under perl 5.14.4.

-----------------------------------------------------------------
[Please describe your issue here]

===============
package Trouble;

sub new { bless [] }

sub DESTROY { $@​ = 'Bad things if this prints!' };

package main;

eval {
my $baddie = Trouble->new();

sub {
$baddie;
die 'This should print.';
}->();
};
my $err = $@​;
print "From Perl $^V​: $err";

The above prints​:

From Perl v5.14.4​: Bad things if this prints!

Looks like the closure is holding onto a reference to $baddie for too
long.

I suspect that this is related to #123738.

Persists in perl-5.24.0.

--
James E Keenan (jkeenan@​cpan.org)

[p5pRT]

From @jkeenan

123773.pl

[p5pRT]

The RT System itself - Status changed from 'new' to 'open'

[p5pRT]

From @iabyn

On Thu, Jan 05, 2017 at 12​:13​:54PM -0800, James E Keenan via RT wrote​:

On Mon, 09 Feb 2015 20​:31​:11 GMT, felipe@​felipegasper.com wrote​:

This is a bug report for perl from felipe@​felipegasper.com,
generated with the help of perlbug 1.39 running under perl 5.14.4.

-----------------------------------------------------------------
[Please describe your issue here]

===============
package Trouble;

sub new { bless [] }

sub DESTROY { $@​ = 'Bad things if this prints!' };

package main;

eval {
my $baddie = Trouble->new();

sub {
$baddie;
die 'This should print.';
}->();
};
my $err = $@​;
print "From Perl $^V​: $err";

The above prints​:

From Perl v5.14.4​: Bad things if this prints!

Looks like the closure is holding onto a reference to $baddie for too
long.

I suspect that this is related to #123738.

Persists in perl-5.24.0.

Now fixed by v5.27.0-119-gb66d79a.

--
It's not that I'm afraid to die, I just don't want to be there when it
happens.
  -- Woody Allen

[p5pRT]

@iabyn - Status changed from 'open' to 'pending release'

[p5pRT]

From @khwilliamson

Thank you for filing this report. You have helped make Perl better.

With the release yesterday of Perl 5.28.0, this and 185 other issues have been
resolved.

Perl 5.28.0 may be downloaded via​:
https://metacpan.org/release/XSAWYERX/perl-5.28.0

If you find that the problem persists, feel free to reopen this ticket.

[p5pRT]

@khwilliamson - Status changed from 'pending release' to 'resolved'