[perl #77672] backticks capture text printed to stdout when working with multiple threads on windows

# New Ticket Created by  strop 
# Please include the string:  [perl #77672]
# in the subject line of all future correspondence about this issue. 
# <URL: http://rt.perl.org/rt3/Ticket/Display.html?id=77672 >


This is a bug report for perl from sinantrop@gmail.com,
generated with the help of perlbug 1.39 running under perl 5.12.1.

This program output should include only zzzzzzzzzzzzz\n strings, but 
actually perl version also get printed sometimes.

fork;
for(1..1000)
{
  print "zzzzzzzzzzzzz\n";
  my $r=`perl -v`;
  print $r if($r=~/zzzzzzzzzzzzz/);
}
---
Flags:
    category=core
    severity=medium
---
Site configuration information for perl 5.12.1:

Configured by SYSTEM at Fri May 14 00:24:46 2010.

Summary of my perl5 (revision 5 version 12 subversion 1) configuration:
   
  Platform:
    osname=MSWin32, osvers=5.00, archname=MSWin32-x86-multi-thread
    uname=''
    config_args='undef'
    hint=recommended, useposix=true, d_sigaction=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 -DUSE_SITECUSTOMIZE 
-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 comctl32.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 comctl32.lib msvcrt.lib
    libc=msvcrt.lib, so=dll, useshrplib=true, libperl=perl512.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
    d956618 Make Term::ReadLine::findConsole fall back to STDIN if 
/dev/tty can't be opened
    321e50c Escape patch strings before embedding them in patchlevel.h

---
@INC for perl 5.12.1:
    C:/Perl/site/lib
    C:/Perl/lib
    .

---
Environment for perl 5.12.1:
    HOME (unset)
    LANG (unset)
    LANGUAGE (unset)
    LD_LIBRARY_PATH (unset)
    LOGDIR (unset)
    
PATH=C:\Perl\site\bin;C:\Perl\bin;C:\WINDOWS\system32;C:\WINDOWS;C:\WINDOWS\System32\Wbem
    PERL_BADLANG (unset)
    SHELL (unset)

• [perl #77672] backticks capture text printed to stdout when working with multiple threads on windows by strop