[perl #53562] Zero-length regex bug

# New Ticket Created by  James Mcclure 
# Please include the string:  [perl #53562]
# in the subject line of all future correspondence about this issue. 
# <URL: http://rt.perl.org/rt3/Ticket/Display.html?id=53562 >


This is a bug report for perl from jamcclur@us.ibm.com,
generated with the help of perlbug 1.35 running under perl v5.8.8.


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

# perl zero-length regex bug

# instructions: 
#  1) run with $ARGV[0] = 1, this script prints false
#  2) run with $ARGV[0] = 2, this script prints true
#  3) comment out the $ARGV[0] =~ /1/ line --> this script prints true
$ARGV[0] =~ /1/;
if ( '' =~ // ) {  print "true\n"; }
else { print "false\n"; }

[Please do not change anything below this line]
-----------------------------------------------------------------
---
Flags:
    category=core
    severity=medium
---
Site configuration information for perl v5.8.8:

Configured by SYSTEM at Tue Jul 31 19:34:29 2007.

Summary of my perl5 (revision 5 version 8 subversion 8) configuration:
  Platform:
    osname=MSWin32, osvers=5.00, 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='cl', ccflags ='-nologo -GF -W3 -MD -Zi -DNDEBUG -O1 -DWIN32 
-D_CONSOLE -DNO_STRICT -DHAVE_DES_FCRYPT -DNO_HASH_SEED 
-DUSE_SITECUSTOMIZE -DPRIVLIB_LAST_IN_INC -DPERL_IMPLICIT_CONTEXT 
-DPERL_IMPLICIT_SYS -DUSE_PERLIO -DPERL_MSVCRT_READFIX',
    optimize='-MD -Zi -DNDEBUG -O1',
    cppflags='-DWIN32'
    ccversion='12.00.8804', gccversion='', gccosandvers=''
    intsize=4, longsize=4, ptrsize=4, doublesize=8, byteorder=1234
    d_longlong=undef, longlongsize=8, d_longdbl=define, longdblsize=8
    ivtype='long', ivsize=4, nvtype='double', nvsize=8, Off_t='__int64', 
lseeksize=8
    alignbytes=8, prototype=define
  Linker and Libraries:
    ld='link', ldflags ='-nologo -nodefaultlib -debug -opt:ref,icf 
-libpath:"C:\Perl\lib\CORE"  -machine:x86'
    libpth=\lib
    libs=  oldnames.lib kernel32.lib user32.lib gdi32.lib winspool.lib 
comdlg32.lib advapi32.lib shell32.lib ole32.lib oleaut32.lib  netapi32.lib 
uuid.lib ws2_32.lib mpr.lib winmm.lib  version.lib odbc32.lib odbccp32.lib 
msvcrt.lib
    perllibs=  oldnames.lib kernel32.lib user32.lib gdi32.lib winspool.lib 
 comdlg32.lib advapi32.lib shell32.lib ole32.lib oleaut32.lib netapi32.lib 
uuid.lib ws2_32.lib mpr.lib winmm.lib  version.lib odbc32.lib odbccp32.lib 
msvcrt.lib
    libc=msvcrt.lib, so=dll, useshrplib=true, libperl=perl58.lib
    gnulibc_version=''
  Dynamic Linking:
    dlsrc=dl_win32.xs, dlext=dll, d_dlsymun=undef, ccdlflags=' '
    cccdlflags=' ', lddlflags='-dll -nologo -nodefaultlib -debug 
-opt:ref,icf  -libpath:"C:\Perl\lib\CORE"  -machine:x86'

Locally applied patches:
    ACTIVEPERL_LOCAL_PATCHES_ENTRY
    Iin_load_module moved for compatibility with build 806
    Avoid signal flag SA_RESTART for older versions of HP-UX
    PerlEx support in CGI::Carp
    Less verbose ExtUtils::Install and Pod::Find
    Patch for CAN-2005-0448 from Debian with modifications
    Rearrange @INC so that 'site' is searched before 'perl'
    Partly reverted 24733 to preserve binary compatibility
    MAINT31223 plus additional changes
    31490 Problem bootstraping Win32CORE
    31324 Fix DynaLoader::dl_findfile() to locate .so files again
    31214 Win32::GetLastError fails when first called
    31211 Restore Windows NT support
    31188 Problem killing a pseudo-forked child on Win32
    29732 ANSIfy the PATH environment variable on Windows
    27527,29868 win32_async_check() can loop indefinitely
    26970 Make Passive mode the default for Net::FTP
    26379 Fix alarm() for Windows 2003
    24699 ICMP_UNREACHABLE handling in Net::Ping

---
@INC for perl v5.8.8:
    C:/Perl/site/lib
    C:/Perl/lib
    .

---
Environment for perl v5.8.8:
    HOME (unset)
    LANG (unset)
    LANGUAGE (unset)
    LD_LIBRARY_PATH (unset)
    LOGDIR (unset)
    PATH=C:\Perl\site\bin;C:\Perl\bin;C:\Program 
Files\ThinkPad\Utilities;C:\WINDOWS\system32;C:\WINDOWS;C:\WINDOWS\System32\Wbem;C:\Program 
Files\IBM\Infoprint Select;C:\Notes;C:\Program 
Files\XLView;C:\lotus\compnent;C:\Utilities;C:\Program Files\IBM\Personal 
Communications\;C:\Program Files\IBM\Trace Facility\;C:\WINDOWS\Downloaded 
Program Files;C:\Program Files\IBM\CMVCDC50\bin;C:\Program 
Files\ThinkPad\ConnectUtilities;C:\PROGRA~1\IBM\SQLLIB\BIN;C:\PROGRA~1\IBM\SQLLIB\FUNCTION;C:\PROGRA~1\IBM\SQLLIB\SAMPLES\REPL;C:\Program 
Files\IBM\SQLLIB\\bin;C:\Program Files\SlickEdit\win;C:\Program 
Files\IBM\CMVCDC50;C:\Program Files\SlickEdit 2007\win\
    PERL_BADLANG (unset)
    SHELL (unset)



James McClure
z/OS LDAP Function Test
Tie 295-9665, External 845-435-9665

• [perl #53562] Zero-length regex bug by James Mcclure
• Re: [perl #53562] Zero-length regex bug by Bram
• Re: [perl #53562] Zero-length regex bug by Tony Cook
• Re: [perl #53562] Zero-length regex bug by David Nicol