[perl #134254] (*COMMIT) behaviour when inside a repeated group

# New Ticket Created by  Philip Hazel 
# Please include the string:  [perl #134254]
# in the subject line of all future correspondence about this issue. 
# <URL: https://rt.perl.org/Ticket/Display.html?id=134254 >


To: perlbug@perl.org
Reply-To: ph10@cam.ac.uk
Subject: (*COMMIT) behaviour when inside a repeated group
From: ph10@cam.ac.uk
Cc: builduser
Message-Id: <5.30.0_5771_1562058560@quercite>


This is a bug report for perl from ph10@cam.ac.uk,
generated with the help of perlbug 1.41 running under perl 5.30.0.


-----------------------------------------------------------------
[Please describe your issue here]

Please see the following example:

$ perl -e 'if (abcd =~ /\A(?:.(*COMMIT))*c/) { print "yes >$&<\n"; } else { print "no \n"; }'
yes >abc<

Why does that pattern match? The repeated group should swallow all of "abcd", 
then fail to match "c" and so backtrack onto (*COMMIT), which should fail the 
whole match, shouldn't it?

Philip


[Please do not change anything below this line]
-----------------------------------------------------------------
---
Flags:
    category=core
    severity=low
---
Site configuration information for perl 5.30.0:

Configured by builduser at Tue Jun 18 19:57:11 CEST 2019.

Summary of my perl5 (revision 5 version 30 subversion 0) configuration:
   
  Platform:
    osname=linux
    osvers=5.1.8-arch1-1-arch
    archname=x86_64-linux-thread-multi
    uname='linux flo-64 5.1.8-arch1-1-arch #1 smp preempt sun jun 9 20:28:28 utc 2019 x86_64 gnulinux '
    config_args='-des -Dusethreads -Duseshrplib -Doptimize=-march=x86-64 -mtune=generic -O2 -pipe -fstack-protector-strong -fno-plt -Dprefix=/usr -Dvendorprefix=/usr -Dprivlib=/usr/share/perl5/core_perl -Darchlib=/usr/lib/perl5/5.30/core_perl -Dsitelib=/usr/share/perl5/site_perl -Dsitearch=/usr/lib/perl5/5.30/site_perl -Dvendorlib=/usr/share/perl5/vendor_perl -Dvendorarch=/usr/lib/perl5/5.30/vendor_perl -Dscriptdir=/usr/bin/core_perl -Dsitescript=/usr/bin/site_perl -Dvendorscript=/usr/bin/vendor_perl -Dinc_version_list=none -Dman1ext=1perl -Dman3ext=3perl -Dcccdlflags='-fPIC' -Dlddlflags=-shared -Wl,-O1,--sort-common,--as-needed,-z,relro,-z,now -Dldflags=-Wl,-O1,--sort-common,--as-needed,-z,relro,-z,now'
    hint=recommended
    useposix=true
    d_sigaction=define
    useithreads=define
    usemultiplicity=define
    use64bitint=define
    use64bitall=define
    uselongdouble=undef
    usemymalloc=n
    default_inc_excludes_dot=define
    bincompat5005=undef
  Compiler:
    cc='cc'
    ccflags ='-D_REENTRANT -D_GNU_SOURCE -fwrapv -fno-strict-aliasing -pipe -fstack-protector-strong -I/usr/local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -D_FORTIFY_SOURCE=2'
    optimize='-march=x86-64 -mtune=generic -O2 -pipe -fstack-protector-strong -fno-plt'
    cppflags='-D_REENTRANT -D_GNU_SOURCE -fwrapv -fno-strict-aliasing -pipe -fstack-protector-strong -I/usr/local/include'
    ccversion=''
    gccversion='9.1.0'
    gccosandvers=''
    intsize=4
    longsize=8
    ptrsize=8
    doublesize=8
    byteorder=12345678
    doublekind=3
    d_longlong=define
    longlongsize=8
    d_longdbl=define
    longdblsize=16
    longdblkind=3
    ivtype='long'
    ivsize=8
    nvtype='double'
    nvsize=8
    Off_t='off_t'
    lseeksize=8
    alignbytes=8
    prototype=define
  Linker and Libraries:
    ld='cc'
    ldflags ='-Wl,-O1,--sort-common,--as-needed,-z,relro,-z,now -fstack-protector-strong -L/usr/local/lib'
    libpth=/usr/local/lib /usr/lib/gcc/x86_64-pc-linux-gnu/9.1.0/include-fixed /usr/lib /lib/../lib /usr/lib/../lib /lib /lib64 /usr/lib64
    libs=-lpthread -lgdbm -ldb -ldl -lm -lcrypt -lutil -lc -lgdbm_compat
    perllibs=-lpthread -ldl -lm -lcrypt -lutil -lc
    libc=libc-2.29.so
    so=so
    useshrplib=true
    libperl=libperl.so
    gnulibc_version='2.29'
  Dynamic Linking:
    dlsrc=dl_dlopen.xs
    dlext=so
    d_dlsymun=undef
    ccdlflags='-Wl,-E -Wl,-rpath,/usr/lib/perl5/5.30/core_perl/CORE'
    cccdlflags='-fPIC'
    lddlflags='-shared -Wl,-O1,--sort-common,--as-needed,-z,relro,-z,now -L/usr/local/lib -fstack-protector-strong'


---
@INC for perl 5.30.0:
    /usr/lib/perl5/5.30/site_perl
    /usr/share/perl5/site_perl
    /usr/lib/perl5/5.30/vendor_perl
    /usr/share/perl5/vendor_perl
    /usr/lib/perl5/5.30/core_perl
    /usr/share/perl5/core_perl

---
Environment for perl 5.30.0:
    HOME=/home/ph10
    LANG=en_GB.utf8
    LANGUAGE=en_GB.utf8
    LC_ALL=C
    LC_COLLATE=C
    LD_LIBRARY_PATH (unset)
    LOGDIR (unset)
    PATH=/home/ph10/bin:/usr/local/sbin:/usr/local/bin:/usr/bin:/opt/android-sdk/platform-tools:/opt/android-sdk/tools:/usr/lib/jvm/default/bin:/usr/bin/site_perl:/usr/bin/vendor_perl:/usr/bin/core_perl:/usr/sbin:.:/opt/android-sdk/platform-tools:/opt/android-sdk/tools:/usr/lib/jvm/default/bin:/usr/bin/site_perl:/usr/bin/vendor_perl:/usr/bin/core_perl
    PERL_BADLANG (unset)
    SHELL=/bin/bash

• [perl #134254] (*COMMIT) behaviour when inside a repeated group by Philip Hazel
• Re: [perl #134254] (*COMMIT) behaviour when inside a repeated group by demerphq
• Re: [perl #134254] (*COMMIT) behaviour when inside a repeated group by ph10
• Re: [perl #134254] (*COMMIT) behaviour when inside a repeated group by demerphq
• Re: [perl #134254] (*COMMIT) behaviour when inside a repeated group by ph10