match variables persist between calls to a sort subroutine

[p5pRT]

Migrated from rt.perl.org#76026 (status was 'resolved')

Searchable as RT76026$

[p5pRT]

From @nwc10

Created by @nwc10

$ cat ~/tmp/sorter.pl
#!perl -w
use strict;

sub sorter {
  my $result = $a <=> $b;

  warn $1;
  # And then
  "Leakage" =~ /(.*)/;

  $result;
}

"Win" =~ /(.*)/;

warn "\$1 = '$1'";

my @​b = sort sorter 0..2;

warn "\$1 = '$1'";

print "@​b\n";

print "\nNote the different behaviour for a regular function call​:\n";

$a = $b = 0;
sorter();
sorter();

__END__
$ ~/Reference/5.005_03/bin/perl5.00503 ~/tmp/sorter.pl
$1 = 'Win' at /export/home/nwc10/tmp/sorter.pl line 16.
Win at /export/home/nwc10/tmp/sorter.pl line 7.
Leakage at /export/home/nwc10/tmp/sorter.pl line 7.
$1 = 'Win' at /export/home/nwc10/tmp/sorter.pl line 20.
0 1 2

Note the different behaviour for a regular function call​:
Win at /export/home/nwc10/tmp/sorter.pl line 7.
Win at /export/home/nwc10/tmp/sorter.pl line 7.

I believe that the output should be 'Win' every time.
I suspect that this has been a bug forever. (Well, since perl 2, which added
sort). However, it may realistically be a bug, as 4.036 exhibits this
behaviour​:

$ /usr/local/perl4/bin/perl4.036 sorter.pl
$1 = 'Win' at sorter.pl line 15.
Win at sorter.pl line 6.
Leakage at sorter.pl line 6.
$1 = 'Leakage' at sorter.pl line 19.
0 1 2

Note the different behaviour for a regular function call​:
Leakage at sorter.pl line 6.
Leakage at sorter.pl line 6.

ie $1 persists between all calls to the subroutine. Alternatively, I may
have missed a documented change in behaviour between perl 4 and perl 5.

I've not (yet) been able to build perl 2, to see what it thinks.

(obviously) still present in blead, else I wouldn't be reporting it.

Nicholas Clark

Perl Info

Site configuration information for perl 5.00503:

Configured by nwc10 at Wed Mar 14 19:16:50 GMT 2007.

Summary of my perl5 (5.0 patchlevel 5 subversion 3) configuration:
  Platform:
    osname=freebsd, osvers=6.1-prerelease, archname=i386-freebsd
    uname='freebsd colon.colondot.net 6.1-prerelease freebsd 6.1-prerelease #0: tue mar 28 23:04:45 bst 2006 mbm@colon.colondot.net:usrobjusrsrcsyscolon i386 '
    hint=recommended, useposix=true, d_sigaction=define
    usethreads=undef useperlio=undef d_sfio=undef
  Compiler:
    cc='ccache gcc', optimize='-g', gccversion=3.4.4 [FreeBSD] 20050518
    cppflags='-DHAS_FPSETMASK -DHAS_FLOATINGPOINT_H -DDEBUGGING -I/usr/local/include'
    ccflags ='-DHAS_FPSETMASK -DHAS_FLOATINGPOINT_H -DDEBUGGING -I/usr/local/include'
    stdchar='char', d_stdstdio=undef, usevfork=true
    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='gcc', ldflags ='-Wl,-E  -L/usr/local/lib'
    libpth=/usr/lib /usr/local/lib
    libs=-lgdbm -lm -lc -lcrypt
    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'

Locally applied patches:
    


@INC for perl 5.00503:
    /export/home/nwc10/Reference/5.005_03/lib/perl5/5.00503/i386-freebsd
    /export/home/nwc10/Reference/5.005_03/lib/perl5/5.00503
    /export/home/nwc10/Reference/5.005_03/lib/perl5/site_perl/5.005/i386-freebsd
    /export/home/nwc10/Reference/5.005_03/lib/perl5/site_perl/5.005
    .


Environment for perl 5.00503:
    HOME=/export/home/nwc10
    LANG (unset)
    LANGUAGE (unset)
    LD_LIBRARY_PATH (unset)
    LOGDIR (unset)
    PATH=/export/home/nwc10/bin:/sbin:/bin:/usr/sbin:/usr/bin:/usr/games:/usr/local/sbin:/usr/local/bin:/usr/X11R6/bin:/export/home/nwc10/bin:/usr/local/sbin:/sbin:/usr/sbin
    PERL_BADLANG (unset)
    SHELL=/usr/local/bin/bash

[p5pRT]

From @cpansprout

Fixed by ad021bf.

[p5pRT]

@cpansprout - Status changed from 'new' to 'resolved'