[perl #77966] IPC::Open3 does not work as expected when fileno(STDERR) == 1

# New Ticket Created by  Salvador Fandiño 
# Please include the string:  [perl #77966]
# in the subject line of all future correspondence about this issue. 
# <URL: http://rt.perl.org/rt3/Ticket/Display.html?id=77966 >


This is a bug report for perl from sfandino@yahoo.com,
generated with the help of perlbug 1.39 running under perl 5.10.1.


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

When STDERR is attached to file descriptor 1, IPC::Open3 fails to work as 
expected.

The following command shows it:

  perl -Ilib -MIPC::Open2=open2 -E 'close STDERR; open STDERR, ">&=STDOUT" or 
die; say fileno(STDERR); open2($in, $out, "echo hello")'

The output from the echo command should be send to the pipe created by open2 but 
instead it goes to the screen.

Running it under strace shows that, in the child process, after the pipes have 
been set up, the fh formerly attached to stderr (so formerly fd 1 that has been 
already copied to another fd) is dupped over fd 1 instead of over fd 2

Cheers,

- Salva



[Please do not change anything below this line]
-----------------------------------------------------------------
---
Flags:
    category=library
    severity=medium
    module=IPC::Open3
---
Site configuration information for perl 5.10.1:

Configured by Debian Project at Fri Apr 23 08:18:41 UTC 2010.

Summary of my perl5 (revision 5 version 10 subversion 1) configuration:
   
  Platform:
    osname=linux, osvers=2.6.24-27-server, 
archname=x86_64-linux-gnu-thread-multi
    uname='linux crested 2.6.24-27-server #1 smp fri mar 12 01:23:09 utc 2010 
x86_64 gnulinux '
    config_args='-Dusethreads -Duselargefiles -Dccflags=-DDEBIAN 
-Dcccdlflags=-fPIC -Darchname=x86_64-linux-gnu -Dprefix=/usr 
-Dprivlib=/usr/share/perl/5.10 -Darchlib=/usr/lib/perl/5.10 -Dvendorprefix=/usr 
-Dvendorlib=/usr/share/perl5 -Dvendorarch=/usr/lib/perl5 -Dsiteprefix=/usr/local 
-Dsitelib=/usr/local/share/perl/5.10.1 -Dsitearch=/usr/local/lib/perl/5.10.1 
-Dman1dir=/usr/share/man/man1 -Dman3dir=/usr/share/man/man3 
-Dsiteman1dir=/usr/local/man/man1 -Dsiteman3dir=/usr/local/man/man3 -Dman1ext=1 
-Dman3ext=3perl -Dpager=/usr/bin/sensible-pager -Uafs -Ud_csh -Ud_ualarm 
-Uusesfio -Uusenm -DDEBUGGING=-g -Doptimize=-O2 -Duseshrplib 
-Dlibperl=libperl.so.5.10.1 -Dd_dosuid -des'
    hint=recommended, useposix=true, d_sigaction=define
    useithreads=define, usemultiplicity=define
    useperlio=define, d_sfio=undef, uselargefiles=define, usesocks=undef
    use64bitint=define, use64bitall=define, uselongdouble=undef
    usemymalloc=n, bincompat5005=undef
  Compiler:
    cc='cc', ccflags ='-D_REENTRANT -D_GNU_SOURCE -DDEBIAN -fno-strict-aliasing 
-pipe -fstack-protector -I/usr/local/include -D_LARGEFILE_SOURCE 
-D_FILE_OFFSET_BITS=64',
    optimize='-O2 -g',
    cppflags='-D_REENTRANT -D_GNU_SOURCE -DDEBIAN -fno-strict-aliasing -pipe 
-fstack-protector -I/usr/local/include'
    ccversion='', gccversion='4.4.3', gccosandvers=''
    intsize=4, longsize=8, ptrsize=8, doublesize=8, byteorder=12345678
    d_longlong=define, longlongsize=8, d_longdbl=define, longdblsize=16
    ivtype='long', ivsize=8, nvtype='double', nvsize=8, Off_t='off_t', 
lseeksize=8
    alignbytes=8, prototype=define
  Linker and Libraries:
    ld='cc', ldflags =' -fstack-protector -L/usr/local/lib'
    libpth=/usr/local/lib /lib /usr/lib /lib64 /usr/lib64
    libs=-lgdbm -lgdbm_compat -ldb -ldl -lm -lpthread -lc -lcrypt
    perllibs=-ldl -lm -lpthread -lc -lcrypt
    libc=/lib/libc-2.11.1.so, so=so, useshrplib=true, libperl=libperl.so.5.10.1
    gnulibc_version='2.11.1'
  Dynamic Linking:
    dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags='-Wl,-E'
    cccdlflags='-fPIC', lddlflags='-shared -O2 -g -L/usr/local/lib 
-fstack-protector'

Locally applied patches:
    

---
@INC for perl 5.10.1:
    /etc/perl
    /usr/local/lib/perl/5.10.1
    /usr/local/share/perl/5.10.1
    /usr/lib/perl5
    /usr/share/perl5
    /usr/lib/perl/5.10
    /usr/share/perl/5.10
    /usr/local/lib/site_perl
    .

---
Environment for perl 5.10.1:
    HOME=/home/salva
    LANG=en_US.utf8
    LANGUAGE (unset)
    LD_LIBRARY_PATH (unset)
    LOGDIR (unset)
    PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games
    PERL_BADLANG (unset)
    SHELL=/bin/bash

• [perl #77966] IPC::Open3 does not work as expected when fileno(STDERR) == 1 by Eric Brine via RT
• [perl #77966] IPC::Open3 does not work as expected when fileno(STDERR) == 1 by Salvador Fandiño