[perl #122873] SEGV in Perl_hv_common with 5.20.1 and Encode 2.62

# New Ticket Created by  (Andreas J. Koenig) 
# Please include the string:  [perl #122873]
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# <URL: https://rt.perl.org/Ticket/Display.html?id=122873 >


Thanks to Slaven Rezić for bringing this candidate to my attention.

The SEGV only happens occasionally while running the test
t/302-content-negotiation-charset.t that comes with
DROLSKY/HTTP-Headers-ActionPack-0.09.tar.gz with
DANKOGAI/Encode-2.62.tar.gz installed.

I just have observed it with 5.20.1 but according to cpantesters it
seems the same happened with 5.20.0, 5.21.1, and 5.21.3.

Very similar to my current observation is
http://www.cpantesters.org/cpan/report/45835631 where Encode
2.60 was involved.

Here is my stacktrace:

  Core was generated by `/home/sand/src/perl/repoperls/installed-perls/perl/v5.20.1/127e/bin/perl -Mblib'.
  Program terminated with signal SIGSEGV, Segmentation fault.
  #0  0x0000000000499570 in Perl_hv_common (hv=0xa, keysv=0x2d7b8f0, 
      key=0x2d86b70 "iso-8859-2", klen=10, flags=-1022775292, action=10, val=0x0, 
      hash=1) at hv.c:637

  warning: Source file is more recent than executable.
  637             goto not_found;
  (gdb) bt
  #0  0x0000000000499570 in Perl_hv_common (hv=0xa, keysv=0x2d7b8f0, 
      key=0x2d86b70 "iso-8859-2", klen=10, flags=-1022775292, action=10, val=0x0, 
      hash=1) at hv.c:637
  #1  0x00000000004a5d8a in Perl_pp_helem () at pp_hot.c:1768
  #2  0x000000000049e0e3 in Perl_runops_standard () at run.c:42
  #3  0x0000000000435371 in Perl_call_sv (sv=0x2d81c20, flags=flags@entry=2)
      at perl.c:2756
  #4  0x0000000000435828 in Perl_call_pv (
      sub_name=sub_name@entry=0x7fd6d1916c10 "Encode::MIME::Name::get_mime_name", 
      flags=flags@entry=2) at perl.c:2645
  #5  0x00007fd6d191387a in XS_Encode__XS_mime_name (cv=<optimized out>)
      at Encode.xs:715
  #6  0x00000000004a5220 in Perl_pp_entersub () at pp_hot.c:2794
  #7  0x000000000049e0e3 in Perl_runops_standard () at run.c:42
  #8  0x000000000043b8c8 in S_run_body (oldscope=1) at perl.c:2456
  #9  perl_run (my_perl=<optimized out>) at perl.c:2372
  #10 0x000000000041de25 in main (argc=3, argv=0x7ffffd6ab278, env=0x7ffffd6ab298)
      at perlmain.c:114

I attach a valgrind output from running

  env PERL_DESTRUCT_LEVEL=2 valgrind  --num-callers=5 \
  /home/sand/src/perl/repoperls/installed-perls/perl/v5.20.1/127e/bin/perl \
  -Mblib  t/302-content-negotiation-charset.t

-- 
andreas

• [perl #122873] SEGV in Perl_hv_common with 5.20.1 and Encode 2.62 by Tony Cook via RT
• [perl #122873] SEGV in Perl_hv_common with 5.20.1 and Encode 2.62 by perlbug-followup