From @geeknik

{my($f,$b),($0),my($f,$b)} causes an assertion failure in Perl_rpeep. This bug was found using American Fuzzy Lop. Perl v5.23.6 (v5.23.5-113-g406d554) was compiled as follows​:

./Configure -des -Dusedevel -DDEBUGGING -Dcc=afl-gcc -Doptimize=-O2\ -g && AFL_HARDEN=1 make -j6

valgrind -q ~/perl/perl test00
perl​: op.c​:13716​: Perl_rpeep​: Assertion `oldoldop->op_next == oldop' failed.
Aborted

perl​: op.c​:13716​: Perl_rpeep​: Assertion `oldoldop->op_next == oldop' failed.
Program received signal SIGABRT, Aborted.
0x00007ffff6d90165 in *__GI_raise (sig=<optimized out>) at ../nptl/sysdeps/unix/sysv/linux/raise.c​:64
64 ../nptl/sysdeps/unix/sysv/linux/raise.c​: No such file or directory.
(gdb) bt
#0 0x00007ffff6d90165 in *__GI_raise (sig=<optimized out>) at ../nptl/sysdeps/unix/sysv/linux/raise.c​:64
#1 0x00007ffff6d933e0 in *__GI_abort () at abort.c​:92
#2 0x00007ffff6d89311 in *__GI___assert_fail (
  assertion=assertion@​entry=0xe81a79 "oldoldop->op_next == oldop", file=<optimized out>,
  file@​entry=0xf50f22 "op.c", line=line@​entry=13716, function=function@​entry=0xe965f3 "Perl_rpeep")
  at assert.c​:81
#3 0x00000000004c324d in Perl_rpeep (o=0x11c8e80) at op.c​:13716
#4 0x000000000048b0f6 in Perl_newPROG (o=0x11c8c88) at op.c​:4113
#5 0x000000000065cf18 in Perl_yyparse (gramtype=gramtype@​entry=258) at perly.y​:120
#6 0x000000000052e625 in S_parse_body (env=env@​entry=0x0, xsinit=xsinit@​entry=0x42e190 <xs_init>)
  at perl.c​:2312
#7 0x0000000000534737 in perl_parse (my_perl=<optimized out>, xsinit=xsinit@​entry=0x42e190 <xs_init>,
  argc=<optimized out>, argv=<optimized out>, env=env@​entry=0x0) at perl.c​:1634
#8 0x000000000042dda8 in main (argc=2, argv=0x7fffffffe668, env=0x7fffffffe680) at perlmain.c​:114

From @iabyn

On Tue, Dec 08, 2015 at 10​:51​:15AM -0800, Brian Carpenter wrote​:

# New Ticket Created by Brian Carpenter
# Please include the string​: [perl #126844]
# in the subject line of all future correspondence about this issue.
# <URL​: https://rt-archive.perl.org/perl5/Ticket/Display.html?id=126844 >

{my($f,$b),($0),my($f,$b)} causes an assertion failure in Perl_rpeep.

Fixed by f5885b0; more general fixes in the follow-up commits in the
branch 4945b30.

--
You're only as old as you look.

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

@iabyn - Status changed from 'open' to 'resolved'