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[perl #23030] Error in negative lookahead with alternations

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From:
Erik Corry
Date:
July 17, 2003 21:24
Subject:
[perl #23030] Error in negative lookahead with alternations
Message ID:
rt-23030-61218.8.07882041185579@rt.perl.org
# New Ticket Created by  Erik Corry 
# Please include the string:  [perl #23030]
# in the subject line of all future correspondence about this issue. 
# <URL: http://rt.perl.org/rt2/Ticket/Display.html?id=23030 >



This is a bug report for perl from erik@arbat.com,
generated with the help of perlbug 1.34 running under perl v5.8.0.


-----------------------------------------------------------------
[Please enter your report here]

The following program prints 'match 1' when I would expect
'no match'.  It has to be just so: Remove one . and it
works as expected:

#!/usr/local/bin/perl

$text = "........abcd";

if ($text =~ /(.*)a(?!(?:b|AB)*c)(.*)d/x) {
    print "match 1 '$1', '$2'\n";
} else {
    print "no match\n";
}

I get the same error on Windows (Active Perl 5.8).


[Please do not change anything below this line]
-----------------------------------------------------------------
---
Flags:
    category=core
    severity=medium
---
Site configuration information for perl v5.8.0:

Configured by bhcompile at Sun Sep  1 23:55:07 EDT 2002.

Summary of my perl5 (revision 5.0 version 8 subversion 0) configuration:
  Platform:
    osname=linux, osvers=2.4.18-11smp, archname=i386-linux-thread-multi
    uname='linux daffy.perf.redhat.com 2.4.18-11smp #1 smp thu aug 15 06:41:59 edt 2002 i686 i686 i386 gnulinux '
    config_args='-des -Doptimize=-O2 -march=i386 -mcpu=i686 -Dmyhostname=localhost -Dperladmin=root@localhost -Dcc=gcc -Dcf_by=Red Hat, Inc. -Dinstallprefix=/usr -Dprefix=/usr -Darchname=i386-linux -Dvendorprefix=/usr -Dsiteprefix=/usr -Duseshrplib -Dusethreads -Duseithreads -Duselargefiles -Dd_dosuid -Dd_semctl_semun -Di_db -Ui_ndbm -Di_gdbm -Di_shadow -Di_syslog -Dman3ext=3pm -Duseperlio -Dinstallusrbinperl -Ubincompat5005 -Uversiononly -Dpager=/usr/bin/less -isr'
    hint=recommended, useposix=true, d_sigaction=define
    usethreads=define use5005threads=undef useithreads=define usemultiplicity=define
    useperlio=define d_sfio=undef uselargefiles=define usesocks=undef
    use64bitint=undef use64bitall=undef uselongdouble=undef
    usemymalloc=n, bincompat5005=undef
  Compiler:
    cc='gcc', ccflags ='-D_REENTRANT -D_GNU_SOURCE -fno-strict-aliasing -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -I/usr/include/gdbm',
    optimize='-O2 -march=i386 -mcpu=i686',
    cppflags='-D_REENTRANT -D_GNU_SOURCE -fno-strict-aliasing -I/usr/include/gdbm'
    ccversion='', gccversion='3.2 20020822 (Red Hat Linux Rawhide 3.2-5)', 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, prototype=define
  Linker and Libraries:
    ld='gcc', ldflags =' -L/usr/local/lib'
    libpth=/usr/local/lib /lib /usr/lib
    libs=-lnsl -lgdbm -ldb -ldl -lm -lpthread -lc -lcrypt -lutil
    perllibs=-lnsl -ldl -lm -lpthread -lc -lcrypt -lutil
    libc=/lib/libc-2.2.92.so, so=so, useshrplib=true, libperl=libperl.so
    gnulibc_version='2.2.92'
  Dynamic Linking:
    dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags='-rdynamic -Wl,-rpath,/usr/lib/perl5/5.8.0/i386-linux-thread-multi/CORE'
    cccdlflags='-fpic', lddlflags='-shared -L/usr/local/lib'

Locally applied patches:
    

---
@INC for perl v5.8.0:
    /usr/lib/perl5/5.8.0/i386-linux-thread-multi
    /usr/lib/perl5/5.8.0
    /usr/lib/perl5/site_perl/5.8.0/i386-linux-thread-multi
    /usr/lib/perl5/site_perl/5.8.0
    /usr/lib/perl5/site_perl
    /usr/lib/perl5/vendor_perl/5.8.0/i386-linux-thread-multi
    /usr/lib/perl5/vendor_perl/5.8.0
    /usr/lib/perl5/vendor_perl
    .

---
Environment for perl v5.8.0:
    HOME=/usr/users/erik
    LANG=en_US
    LANGUAGE (unset)
    LD_LIBRARY_PATH (unset)
    LOGDIR (unset)
    PATH=/bin:/usr/bin:/sbin:/usr/sbin:/usr/X11R6/bin:/usr/local/j2sdk1.4.1/bin:/usr/local/bin:/usr/local/kaffe/bin:/usr/users/erik/local/bin:/usr/local/informix/bin:/usr/users/erik/beta/r5.3/../bin:/usr/users/erik/beta/r5.3/../bin/admin
    PERL_BADLANG (unset)
    SHELL=/bin/bash

-- 
Erik Corry erik@arbat.com


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