[perl #47762] 5.10: different behaviour of duplicated named capturing parens with/without (?|...)

# New Ticket Created by  Andrew 
# Please include the string:  [perl #47762]
# in the subject line of all future correspondence about this issue. 
# <URL: http://rt.perl.org/rt3/Ticket/Display.html?id=47762 >


This is a bug report for perl from andy@shitov.ru,
generated with the help of perlbug 1.36 running under perl 5.8.8.


-----------------------------------------------------------------
The resetting parens (?| ... ) in regexps wokr wrong when it is
used together with named captures where two of them have the same name
but are in different branches of "|".

Here is an example:

use feature 'say';

my $re = qr/
        (?|
            (?<year>\d{4})  (\d\d)  (\d\d)
        |
            (\w+),  \s*  (?<year>\d{4})
        )
    /x;

'20071122' =~ $re;
#say "$1 / $2 / $3";
say $+{year};       # prints '2007'

'November, 2007' =~ $re;
#say "$1 / $2";
say $+{year};       # prints 'November'

It looks like $+{year} in the second match prints the $1 when first
occurance of ?<year> is in the first capturing parens (), $2 when
?<year> moved into second and $3 (empty respective) when testing

(\d{4})  (\d\d)  (?<year>\d\d)


When (?| ... ) is removed, the behaviour changes and the programme
prints '2007' twice as expected.

-----------------------------------------------------------------
---
Flags:
    category=core
    severity=low
---
This perlbug was built using Perl 5.10.0 - Thu Nov 22 14:37:24 2007
It is being executed now by  Perl 5.8.8 - Tue Aug 29 12:39:43 2006.

Site configuration information for perl 5.8.8:

Configured by SYSTEM at Tue Aug 29 12:39:43 2006.

Summary of my perl5 (revision 5 version 8 subversion 8) configuration:
  Platform:
    osname=MSWin32, osvers=5.0, archname=MSWin32-x86-multi-thread
    uname=''
    config_args='undef'
    hint=recommended, useposix=true, d_sigaction=undef
    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 ='-DNDEBUG -DWIN32 -D_CONSOLE -DNO_STRICT -DHAVE_DES_FCRYPT -DNO_HASH_SEED -DUSE_SITECUSTOMIZE -DPERL_IMPLICIT_CONTEXT -DPERL_IMPLICIT_SYS -DUSE_PERLIO -DPERL_MSVCRT_READFIX -DHASATTRIBUTE -fno-strict-aliasing',
    optimize='-O2',
    cppflags='-DWIN32'
    ccversion='12.00.8804', gccversion='3.4.5 (mingw special)', gccosandvers=''
    intsize=4, longsize=4, ptrsize=4, doublesize=8, byteorder=1234
    d_longlong=undef, longlongsize=8, d_longdbl=define, longdblsize=10
    ivtype='long', ivsize=4, nvtype='double', nvsize=8, Off_t='__int64', lseeksize=8
    alignbytes=8, prototype=define
  Linker and Libraries:
    ld='gcc', ldflags ='-nologo -nodefaultlib -debug -opt:ref,icf  -libpath:"C:\Perl\lib\CORE"  -machine:x86'
    libpth=\lib
    libs=-lkernel32 -luser32 -lgdi32 -lwinspool -lcomdlg32 -ladvapi32 -lshell32 -lole32 -loleaut32 -lnetapi32 -luuid -lws2_32 -lmpr -lwinmm -lversion -lodbc32 -lodbccp32 -lmsvcrt
    perllibs=-lkernel32 -luser32 -lgdi32 -lwinspool -lcomdlg32 -ladvapi32 -lshell32 -lole32 -loleaut32 -lnetapi32 -luuid -lws2_32 -lmpr -lwinmm -lversion -lodbc32 -lodbccp32 -lmsvcrt
    libc=msvcrt.lib, so=dll, useshrplib=yes, libperl=perl58.lib
    gnulibc_version=''
  Dynamic Linking:
    dlsrc=dl_win32.xs, dlext=dll, d_dlsymun=undef, ccdlflags=' '
    cccdlflags=' ', lddlflags='-mdll -L"C:\Perl\lib\CORE"'

Locally applied patches:
    ACTIVEPERL_LOCAL_PATCHES_ENTRY
    perl-current@32448

---
@INC for perl 5.8.8:
    C:/Perl/site/lib
    C:/Perl/lib
    .

---
Environment for perl 5.8.8:
    HOME (unset)
    LANG (unset)
    LANGUAGE (unset)
    LD_LIBRARY_PATH (unset)
    LOGDIR (unset)
    PATH=C:\Perl510\site\bin;C:\Perl510\bin;c:\program files\imagemagick-6.3.4-q16;C:\Program Files\ActiveState Komodo Edit 4.0\;C:\Python\.;C:\Perl\bin\;C:\WINDOWS\SYSTEM32;C:\WINDOWS;C:\WINDOWS\SYSTEM32\WBEM;C:\PROGRAM FILES\ATI TECHNOLOGIES\ATI.ACE\;c:\ghc\bin;c:\ghc\ghc-6.6;C:\Program Files\Intel\IDB\9.1\IA32\Script;C:\Program Files\Intel\Compiler\C++\9.1\EM64T\Bin;c:\mingw\bin;C:\ghc\ghc-6.4.2\gcc-lib;c:\pugs;C:\Program Files\Common Files\Adobe\AGL;c:\Program Files\Microsoft SQL Server\90\Tools\binn\;C:\Program Files\Java\jdk1.5.0_07\bin;C:\Program Files\MySQL\MySQL Server 5.0\bin;c:\usr\bin;d:\usr\local\bin;c:\parser\;C:\Program Files\QuickTime\QTSystem\;C:\Program Files\Haskell\bin;C:\ghc\bin;
    PERL_BADLANG (unset)
    SHELL (unset)

• [perl #47762] 5.10: different behaviour of duplicated named capturing parens with/without (?|...) by Andrew
• Re: [perl #47762] 5.10: different behaviour of duplicated named capturing parens with/without (?|...) by Rafael Garcia-Suarez
• Re: [perl #47762] 5.10: different behaviour of duplicated named capturing parens with/without (?|...) by demerphq