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[perl #128634] Unexpected: Use of freed value in iteration at ...

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From:
KES
Date:
July 17, 2016 04:08
Subject:
[perl #128634] Unexpected: Use of freed value in iteration at ...
Message ID:
rt-4.0.18-18915-1468688414-735.128634-75-0@perl.org
# New Ticket Created by  KES 
# Please include the string:  [perl #128634]
# in the subject line of all future correspondence about this issue. 
# <URL: https://rt.perl.org/Ticket/Display.html?id=128634 >


Message-Id: <5.25.1_11967_1468687426@keswork>
To: perlbug@perl.org
From: kes-kes@yandex.ru
Subject: Use of freed value in iteration at ...
Cc: kes-kes@yandex.ru
Reply-To: kes-kes@yandex.ru


This is a bug report for perl from kes-kes@yandex.ru,
generated with the help of perlbug 1.40 running under perl 5.25.1.


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

$ cat example.pl
my $hash =  { a => {}, b =>  {} };
for my $value ( values %$hash ) {
    delete $hash->{ b };
    print $value;  #<<<<< Use of freed value in iteration at ...
}

$ perl example.pl
Use of freed value in iteration at iter_free line 4.
HASH(0x1590178)
$ perl example.pl
HASH(0x17e6d38)HASH(0x17d1178)

That is not expected to get different behavior for two runs

Maybe related to:
https://rt.perl.org/Public/Bug/Display.html?id=85026 which was closed as of 5.14.1
https://metacpan.org/pod/distribution/perl/pod/perl5141delta.pod#Bug-Fixes
 * A bug has been fixed that would cause a "Use of freed value in iteration"
   error if the next two hash elements that would be iterated over are deleted. [perl #85026]

https://rt.perl.org/Public/Bug/Display.html?id=89548
https://rt.perl.org/Public/Bug/Display.html?id=77706


[Please do not change anything below this line]
-----------------------------------------------------------------
---
Flags:
    category=core
    severity=low
---
Site configuration information for perl 5.25.1:

Configured by kes at Sun Jun  5 17:16:28 EEST 2016.

Summary of my perl5 (revision 5 version 25 subversion 1) configuration:
   
  Platform:
    osname=linux, osvers=3.13.0-37-generic, archname=x86_64-linux
    uname='linux keswork 3.13.0-37-generic #64-ubuntu smp mon sep 22 21:28:38 utc 2014 x86_64 x86_64 x86_64 gnulinux '
    config_args='-de -Dprefix=/home/kes/perl5/perlbrew/perls/perl-5.25.1 -Dusedevel -Aeval:scriptdir=/home/kes/perl5/perlbrew/perls/perl-5.25.1/bin'
    hint=recommended, useposix=true, d_sigaction=define
    useithreads=undef, usemultiplicity=undef
    use64bitint=define, use64bitall=define, uselongdouble=undef
    usemymalloc=n, bincompat5005=undef
  Compiler:
    cc='cc', ccflags ='-fwrapv -fno-strict-aliasing -pipe -fstack-protector -I/usr/local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64',
    optimize='-O2',
    cppflags='-fwrapv -fno-strict-aliasing -pipe -fstack-protector -I/usr/local/include'
    ccversion='', gccversion='4.8.4', gccosandvers=''
    intsize=4, longsize=8, ptrsize=8, doublesize=8, byteorder=12345678, doublekind=3
    d_longlong=define, longlongsize=8, d_longdbl=define, longdblsize=16, longdblkind=3
    ivtype='long', ivsize=8, nvtype='double', nvsize=8, Off_t='off_t', lseeksize=8
    alignbytes=8, prototype=define
  Linker and Libraries:
    ld='cc', ldflags =' -fstack-protector -L/usr/local/lib'
    libpth=/usr/local/lib /usr/lib/gcc/x86_64-linux-gnu/4.8/include-fixed /usr/include/x86_64-linux-gnu /usr/lib /lib/x86_64-linux-gnu /lib/../lib /usr/lib/x86_64-linux-gnu /usr/lib/../lib /lib
    libs=-lpthread -lnsl -ldl -lm -lcrypt -lutil -lc
    perllibs=-lpthread -lnsl -ldl -lm -lcrypt -lutil -lc
    libc=libc-2.19.so, so=so, useshrplib=false, libperl=libperl.a
    gnulibc_version='2.19'
  Dynamic Linking:
    dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags='-Wl,-E'
    cccdlflags='-fPIC', lddlflags='-shared -O2 -L/usr/local/lib -fstack-protector'

Locally applied patches:
    Devel::PatchPerl 1.38

---
@INC for perl 5.25.1:
    /home/kes/perl5/perlbrew/perls/perl-5.25.1/lib/site_perl/5.25.1/x86_64-linux
    /home/kes/perl5/perlbrew/perls/perl-5.25.1/lib/site_perl/5.25.1
    /home/kes/perl5/perlbrew/perls/perl-5.25.1/lib/5.25.1/x86_64-linux
    /home/kes/perl5/perlbrew/perls/perl-5.25.1/lib/5.25.1
    .

---
Environment for perl 5.25.1:
    HOME=/home/kes
    LANG=ru_UA.UTF-8
    LANGUAGE=en
    LC_MESSAGES=en_US.UTF-8
    LD_LIBRARY_PATH (unset)
    LOGDIR (unset)
    PATH=/home/kes/perl5/perlbrew/bin:/home/kes/perl5/perlbrew/perls/perl-5.25.1/bin:/home/kes/perl5/bin:/home/kes/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games
    PERLBREW=command perlbrew
    PERLBREW_BASHRC_VERSION=0.75
    PERLBREW_HOME=/home/kes/.perlbrew
    PERLBREW_MANPATH=/home/kes/perl5/perlbrew/perls/perl-5.25.1/man
    PERLBREW_PATH=/home/kes/perl5/perlbrew/bin:/home/kes/perl5/perlbrew/perls/perl-5.25.1/bin
    PERLBREW_PERL=perl-5.25.1
    PERLBREW_ROOT=/home/kes/perl5/perlbrew
    PERLBREW_VERSION=0.75
    PERL_BADLANG (unset)
    SHELL=/bin/bash


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