5.5.3 vs 5.6.1: A relust of split() changed when split's regexp has capture-()s

[p5pRT]

Migrated from rt.perl.org#7709 (status was 'resolved')

Searchable as RT7709$

[p5pRT]

From hac@subscribe.ru

Description

A result of split() changed when split's regexp has capture-()s

5.005_03 - array elements for unmatched () was undef
5.6.1 - array elements for unmatched () is ''

Test case from real life - parsing HTML's &...; symbol-entity.

Test script source and perl -V below.

How to reproduce

./test -script 'aaa { bbb Ǐ ccc   ddd'

Output​:

5.005_03 5.6.1
--------- ------
 
field 'aaa ' field 'aaa '
$1 UN-defined $1 defined and is ''
$2 defined and is '123' $2 defined and is '123'
$3 UN-defined $3 defined and is ''
 
field ' bbb ' field ' bbb '
$1 UN-defined $1 defined and is ''
$2 UN-defined $2 defined and is ''
$3 defined and is '01CF' $3 defined and is '01CF'
 
field ' ccc ' field ' ccc '
$1 defined and is 'nbsp' $1 defined and is 'nbsp'
$2 UN-defined $2 defined and is ''
$3 UN-defined $3 defined and is ''
 
field ' ddd' field ' ddd'

Perl -V for 5.005_03

---

Summary of my perl5 (5.0 patchlevel 5 subversion 3) configuration​:
  Platform​:
  osname=linux, osvers=2.2.10, archname=i586-linux
  uname='linux fatou 2.2.10 #2 smp thu jul 15 15​:03​:02 mest 1999 i686 unknown '
  hint=recommended, useposix=true, d_sigaction=define
  usethreads=undef useperlio=undef d_sfio=undef
  Compiler​:
  cc='cc', optimize='-O2 -pipe', 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 Jul 22 1999 21​:20​:02
  @​INC​:
  /usr/lib/perl5/5.00503/i586-linux
  /usr/lib/perl5/5.00503
  /usr/lib/perl5/site_perl/5.005/i586-linux
  /usr/lib/perl5/site_perl/5.005
  .

Perl -V for 5.6.1

---

Summary of my perl5 (revision 5.0 version 6 subversion 1) configuration​:
  Platform​:
  osname=freebsd, osvers=4.3-release, archname=i386-freebsd-thread
  uname='freebsd serega.citycat.ru 4.3-release freebsd 4.3-release #0​: mon jun 25 12​:27​:41 msd 2001
root@​serega.citycat.ru​:usrsrcsyscompileserega i386 '
  config_args='-d -Dusethreads -Duse5005threads'
  hint=previous, useposix=true, d_sigaction=define
  usethreads=define use5005threads=define useithreads=undef usemultiplicity=undef
  useperlio=undef d_sfio=undef uselargefiles=define usesocks=undef
  use64bitint=undef use64bitall=undef uselongdouble=undef
  Compiler​:
  cc='cc', ccflags ='-fno-strict-aliasing -I/usr/local/include',
  optimize='-O',
  cppflags='-fno-strict-aliasing -I/usr/local/include'
  ccversion='', gccversion='2.95.3 [FreeBSD] 20010315 (release)', gccosandvers=''
  intsize=4, longsize=4, ptrsize=4, doublesize=8, byteorder=1234
  d_longlong=define, longlongsize=8, d_longdbl=define, longdblsize=12
  ivtype='long', ivsize=4, nvtype='double', nvsize=8, Off_t='off_t', lseeksize=8
  alignbytes=4, usemymalloc=n, prototype=define
  Linker and Libraries​:
  ld='cc', ldflags ='-pthread -Wl,-E -L/usr/local/lib'
  libpth=/usr/lib /usr/local/lib
  libs=-lm -lc_r -lcrypt -lutil
  perllibs=-lm -lc_r -lcrypt -lutil
  libc=, so=so, useshrplib=false, libperl=libperl.a
  Dynamic Linking​:
  dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags=' '
  cccdlflags='-DPIC -fpic', lddlflags='-shared -L/usr/local/lib'

Characteristics of this binary (from libperl)​:
  Compile-time options​: USE_THREADS USE_LARGE_FILES PERL_IMPLICIT_CONTEXT
  Built under freebsd
  Compiled at Jul 6 2001 19​:15​:27
  @​INC​:
  /usr/local/lib/perl5/5.6.1/i386-freebsd-thread
  /usr/local/lib/perl5/5.6.1
  /usr/local/lib/perl5/site_perl/5.6.1/i386-freebsd-thread
  /usr/local/lib/perl5/site_perl/5.6.1
  /usr/local/lib/perl5/site_perl
  .

Test script source​:

---

#!/usr/bin/perl

@​A = split(/&(?​:([a-zA-Z0-9]+)|#([0-9]+)|#[xX]([0-9a-hA-H]+));/go,@​ARGV[0]);

while(@​A)
{
  print "field '",shift(@​A),"'\n";

  last unless(@​A);

  foreach (qw(1 2 3))
  {
  $a = shift(@​A);
  print '$',$_,' ';
  if (defined $a)
  {
  print "defined and is '$a'\n";
  }
  else
  {
  print "UN-defined\n";
  }
  }
  print "\n";
}

---

---

Pavel Yakovlev
mailto​: hac@​subscribe.ru ICQ 8085803
PPY-RIPN PY125-RIPE

---

"When God talks with me it's the miracle. When I talk with God it's the madness"

[p5pRT]

From [Unknown Contact. See original ticket]

A result of split() changed when split's regexp has capture-()s

5.005_03 - array elements for unmatched () was undef
5.6.1 - array elements for unmatched () is ''

I patched this for bleadperl about a month ago or so. It'll be
"fixed" (it will back to the unmatched-()-returns-undef behavior) in the
next release of Perl.

[p5pRT]

p5p@spam.wizbit.be - Status changed from 'open' to 'resolved'