why it segfaults?

[p5pRT]

Migrated from rt.perl.org#967 (status was 'resolved')

Searchable as RT967$

[p5pRT]

From frank@orion.ideare.com

Summary of my perl5 (5.0 patchlevel 5 subversion 3) configuration​:
  Platform​:
  osname=linux, osvers=2.2.1-ac1, archname=i386-linux
  uname='linux porky.devel.redhat.com 2.2.1-ac1 #1 smp mon feb 1
17​:44​:44 est 1999 i686 unknown '
  hint=recommended, useposix=true, d_sigaction=define
  usethreads=undef useperlio=undef d_sfio=undef
  Compiler​:
  cc='cc', optimize='-O2', gccversion=egcs-2.91.66 19990314/Linux
(egcs-1.1.2 release)
  cppflags='-Dbool=char -DHAS_BOOL -I/usr/local/include'
  ccflags ='-Dbool=char -DHAS_BOOL -I/usr/local/include'
  stdchar='char', d_stdstdio=undef, usevfork=false
  intsize=4, longsize=4, ptrsize=4, doublesize=8
  d_longlong=define, longlongsize=8, d_longdbl=define, longdblsize=12
  alignbytes=4, usemymalloc=n, prototype=define
  Linker and Libraries​:
  ld='cc', ldflags =' -L/usr/local/lib'
  libpth=/usr/local/lib /lib /usr/lib
  libs=-lnsl -lndbm -lgdbm -ldb -ldl -lm -lc -lposix -lcrypt
  libc=, so=so, useshrplib=false, libperl=libperl.a
  Dynamic Linking​:
  dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags='-rdynamic'
  cccdlflags='-fpic', lddlflags='-shared -L/usr/local/lib'

Characteristics of this binary (from libperl)​:
  Built under linux
  Compiled at Apr 6 1999 23​:34​:07
  @​INC​:
  /usr/lib/perl5/5.00503/i386-linux
  /usr/lib/perl5/5.00503
  /usr/lib/perl5/site_perl/5.005/i386-linux
  /usr/lib/perl5/site_perl/5.005

I'm using DBI and DBD​::mysql, and, while I try to insert duplicate record
which contains the % char (which is a thing allowed in mysql and I can
do it from the mysql client command line), the perl program fails to
print the mysqld error code and often segaults​:

inserting record​: www.acenet.it/database/Azioni%20innovative%20in%20ambito%20locale%20nel%20campo%20dell%27INFORMATION%20SOCIETY.html

error​:
DBD​::mysql​::db do failed​: Duplicate entry 'www.acenet.it/database/Azioni
135674528nnovative 135674528n%20ambito 1003074360caleel
ampo -1073743128ell%27INFORMATION%20SOCIETY.html'

it does not segfault here, but perl prints this "strange form" of the
error.

but if we add one more %something​:

inserting record​: www.acenet.it/database/Azion%20i%20innovative%20in%20ambito%20locale%20nel%20campo%20dell%27INFORMATION%20SOCIETY.html

Segmentation fault (core dumped)

then I built a debug version of perl and started gdb (sorry, I can't go
further), here are the results​:

(gdb) r -I./lib ~frank/prova.pl
Starting program​: /home2/frank/perldebug/perl5.005_03/./perl -I./lib
~frank/prova.pl
www.acenet.it/database/Azioni%20innovative%20in%20ambito%20locale%20nel%20campo%20dell%27INFORMATION%20SOCIETY.html

Program received signal SIGSEGV, Segmentation fault.
0x80b0352 in Perl_sv_vcatpvfn (sv=0x810fa38,
  pat=0x81bc600 "DBD​::mysql​::db do failed​: Duplicate entry
'www.acenet.it/database/Azioni%20innovative%20in%20ambito%20locale%20nel%20campo%20dell%27INFORMATION%20SOCIETY.html'
for key 1", patlen=169, args=0xbffff998, svargs=0x0,
  svmax=0, used_locale=0x0) at sv.c​:4826
4826 default​: *(va_arg(*args, int*)) = i; break;

(gdb) backtrace
#0 0x80b0352 in Perl_sv_vcatpvfn (sv=0x810fa38,
  pat=0x81bc600 "DBD​::mysql​::db do failed​: Duplicate entry
'www.acenet.it/database/Azioni%20innovative%20in%20ambito%20locale%20nel%20campo%20dell%27INFORMATION%20SOCIETY.html'
for key 1", patlen=169, args=0xbffff998, svargs=0x0,
  svmax=0, used_locale=0x0) at sv.c​:4826
#1 0x80ae27b in Perl_sv_vsetpvfn (sv=0x810fa38,
  pat=0x81bc600 "DBD​::mysql​::db do failed​: Duplicate entry
'www.acenet.it/database/Azioni%20innovative%20in%20ambito%20locale%20nel%20campo%20dell%27INFORMATION%20SOCIETY.html'
for key 1", patlen=169, args=0xbffff998, svargs=0x0,
  svmax=0, used_locale=0x0) at sv.c​:4402
#2 0x808e601 in Perl_mess (
  pat=0x81bc600 "DBD​::mysql​::db do failed​: Duplicate entry
'www.acenet.it/database/Azioni%20innovative%20in%20ambito%20locale%20nel%20campo%20dell%27INFORMATION%20SOCIETY.html'
for key 1", args=0xbffff998) at util.c​:1222
#3 0x808f0a6 in Perl_warn (
  pat=0x81bc600 "DBD​::mysql​::db do failed​: Duplicate entry
'www.acenet.it/database/Azioni%20innovative%20in%20ambito%20locale%20nel%20campo%20dell%27INFORMATION%20SOCIETY.html'
for key 1") at util.c​:1367
#4 0x401af43e in XS_DBI_dispatch ()
#5 0x80a2897 in Perl_pp_entersub () at pp_hot.c​:2255
#6 0x809b5a4 in Perl_runops_debug () at run.c​:66
#7 0x805a77e in perl_run (sv_interp=0x810aef8) at perl.c​:1100
#8 0x8057f53 in main (argc=3, argv=0xbffffd14, env=0xbffffd24) at
perlmain.c​:51
#9 0x400a5cb3 in __libc_start_main (main=0x8057ed0 <main>, argc=3,
argv=0xbffffd14, init=0x80570a8 <_init>,
  fini=0x80f10dc <_fini>, rtld_fini=0x4000a350 <_dl_fini>,
stack_end=0xbffffd0c)
  at ../sysdeps/generic/libc-start.c​:78

I really hope that someone can point me out the right solution, other than
not using % chars in mysql records...

Regards.

Francesco Messineo