From @andk

bisect

commit 20e9643
Author​: David Mitchell <davem@​iabyn.com>
Date​: Sun Oct 25 18​:28​:14 2015 +0000

  split pp_postdec() from pp_postinc() and improve

cpantesters

http​://www.cpantesters.org/cpan/report/599bc628-882f-11e5-b6b4-b541a9884ca8

perl -V

Summary of my perl5 (revision 5 version 23 subversion 5) configuration​:
  Commit id​: 067cec4
  Platform​:
  osname=linux, osvers=4.2.0-1-amd64, archname=x86_64-linux-ld
  uname='linux k83 4.2.0-1-amd64 #1 smp debian 4.2.5-1 (2015-10-27) x86_64 gnulinux '
  config_args='-Dprefix=/home/sand/src/perl/repoperls/installed-perls/perl/v5.23.4-101-g067cec4/127e -Dmyhostname=k83 -Dinstallusrbinperl=n -Uversiononly -Dusedevel -des -Ui_db -Uuseithreads -Duselongdouble -DDEBUGGING=-g'
  hint=recommended, useposix=true, d_sigaction=define
  useithreads=undef, usemultiplicity=undef
  use64bitint=define, use64bitall=define, uselongdouble=define
  usemymalloc=n, bincompat5005=undef
  Compiler​:
  cc='cc', ccflags ='-fwrapv -fno-strict-aliasing -pipe -fstack-protector-strong -I/usr/local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64',
  optimize='-O2 -g',
  cppflags='-fwrapv -fno-strict-aliasing -pipe -fstack-protector-strong -I/usr/local/include'
  ccversion='', gccversion='5.2.1 20151028', 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='long double', nvsize=16, Off_t='off_t', lseeksize=8
  alignbytes=16, prototype=define
  Linker and Libraries​:
  ld='cc', ldflags =' -fstack-protector-strong -L/usr/local/lib'
  libpth=/usr/local/lib /usr/lib/gcc/x86_64-linux-gnu/5/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 -lgdbm -ldb -ldl -lm -lcrypt -lutil -lc -lgdbm_compat
  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 -g -L/usr/local/lib -fstack-protector-strong'

Characteristics of this binary (from libperl)​:
  Compile-time options​: HAS_TIMES PERLIO_LAYERS PERL_COPY_ON_WRITE
  PERL_DONT_CREATE_GVSV
  PERL_HASH_FUNC_ONE_AT_A_TIME_HARD PERL_MALLOC_WRAP
  PERL_PRESERVE_IVUV PERL_USE_DEVEL USE_64_BIT_ALL
  USE_64_BIT_INT USE_LARGE_FILES USE_LOCALE
  USE_LOCALE_COLLATE USE_LOCALE_CTYPE
  USE_LOCALE_NUMERIC USE_LOCALE_TIME USE_LONG_DOUBLE
  USE_PERLIO USE_PERL_ATOF
  Built under linux
  Compiled at Nov 10 2015 15​:47​:39
  %ENV​:
  PERL5LIB=""
  PERL5OPT=""
  PERL5_CPANPLUS_IS_RUNNING="20319"
  PERL5_CPAN_IS_RUNNING="20319"
  PERL_MM_USE_DEFAULT="1"
  @​INC​:
  /home/sand/src/perl/repoperls/installed-perls/perl/v5.23.4-101-g067cec4/127e/lib/site_perl/5.23.5/x86_64-linux-ld
  /home/sand/src/perl/repoperls/installed-perls/perl/v5.23.4-101-g067cec4/127e/lib/site_perl/5.23.5
  /home/sand/src/perl/repoperls/installed-perls/perl/v5.23.4-101-g067cec4/127e/lib/5.23.5/x86_64-linux-ld
  /home/sand/src/perl/repoperls/installed-perls/perl/v5.23.4-101-g067cec4/127e/lib/5.23.5
  .
--
andreas

From @iabyn

On Fri, Nov 13, 2015 at 04​:39​:08PM -0800, Andreas J. Koenig via RT wrote​:

# New Ticket Created by (Andreas J. Koenig)
# Please include the string​: [perl #126637]
# in the subject line of all future correspondence about this issue.
# <URL​: https://rt-archive.perl.org/perl5/Ticket/Display.html?id=126637 >

bisect
------
commit 20e9643
Author​: David Mitchell <davem@​iabyn.com>
Date​: Sun Oct 25 18​:28​:14 2015 +0000

split pp\_postdec\(\) from pp\_postinc\(\) and improve

Now fixed in blead by​:

commit cb45471
Author​: David Mitchell <davem@​iabyn.com>
AuthorDate​: Wed Nov 18 15​:30​:37 2015 +0000
Commit​: David Mitchell <davem@​iabyn.com>
CommitDate​: Wed Nov 18 15​:30​:37 2015 +0000

  sv_inc/dec_nomg()​: croak on GVs etc
 
  RT #126637
 
  Prior to v5.23.4-100-g20e9643, pp_postinc() etc checked whether the SV was
  an AV, non-fake GV, or any other such non-modifiable thinngy; and if so,
  called Perl_croak_no_modify(). That commit of mine removed the check, and
  instead relied on the underlying sv_inc_nomg() function (called by
  pp_postinc()) to do the checking instead. It turns out that while
  sv_inc_nomg() etc does some checks, it wasn't as thorough as pp_postinc().
  So something like
 
  my $y = $_++ for *FOO;
 
  now crashes with an assertion failure in sv_inc_nomg() rather than
  croaking.
 
  This commit adds such checks to sv_inc_nomg() and sv_dec_nomg() - which
  need them anyway, since they may be called from places other than
  pp_postinc() etc.

--
"But Sidley Park is already a picture, and a most amiable picture too.
The slopes are green and gentle. The trees are companionably grouped at
intervals that show them to advantage. The rill is a serpentine ribbon
unwound from the lake peaceably contained by meadows on which the right
amount of sheep are tastefully arranged." -- Lady Croom, "Arcadia"

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

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

From @khwilliamson

Thank you for submitting this report. You have helped make Perl better.
 
With the release of Perl 5.24.0 on May 9, 2016, this and 149 other issues have been resolved.

Perl 5.24.0 may be downloaded via https://metacpan.org/release/RJBS/perl-5.24.0

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