Bug#746804: demonstration script

[David Christensen]

Dear Maintainer,

The bug is triggered if the caller uses a STDIN callback that accesses a 
package or lexical array variable in the caller.


Please see demonstration script and console session, below.


David



2014-05-03 12:51:49 dpchrist at dev ~/sandbox/perl
$ cat IPC-Run-run_stdin-callback-return-array.t
#! /usr/bin/perl
# $Id: IPC-Run-run_stdin-callback-return-array.t,v 1.4 2014-05-03 
19:51:47 dpchrist Exp $
# Demonstrate Perl IPC::Run stdin callback problem returning array
# by David Paul Christensen dpchrist at holgerdanske.com
# Public Domain

use strict;
use warnings;

use IPC::Run qw( run );
use Test::More			tests => 8;

my @cmd = ("true");
our ($i, @i);
my ($in, @in);

ok( run( \@cmd                      ) == 1, "no callback");	#     1
ok (run( \@cmd, sub { return undef }) == 1, "undef");		#     2
ok (run( \@cmd, sub { return ""    }) == 1, "empty string");	#     3
ok (run( \@cmd, sub { return ()    }) == 1, "empty array");	#     4
ok (run( \@cmd, sub { return $i    }) == 1, "package scalar");	#     5
ok (run( \@cmd, sub { return $in   }) == 1, "lexical scalar");	#     6
ok (run( \@cmd, sub { return @i    }) == 1, "package array");	#     7
ok (run( \@cmd, sub { return @in   }) == 1, "lexical array");	#     8

2014-05-03 12:51:51 dpchrist at dev ~/sandbox/perl
$ perl IPC-Run-run_stdin-callback-return-array.t
1..8
ok 1 - no callback
ok 2 - undef
ok 3 - empty string
ok 4 - empty array
ok 5 - package scalar
ok 6 - lexical scalar

2014-05-03 12:51:53 dpchrist at dev ~/sandbox/perl
$ perl -d IPC-Run-run_stdin-callback-return-array.t

Loading DB routines from perl5db.pl version 1.33
Editor support available.

Enter h or `h h' for help, or `man perldebug' for more help.

1..8
main::(IPC-Run-run_stdin-callback-return-array.t:13):
13:	my @cmd = ("true");
   DB<1> b IPC::Run::_write
   DB<2> c
ok 1 - no callback
ok 2 - undef
ok 3 - empty string
ok 4 - empty array
ok 5 - package scalar
ok 6 - lexical scalar
IPC::Run::_write(/usr/share/perl5/IPC/Run.pm:1412):
1412:	   confess 'undef' unless defined $_[0] && defined $_[1];
   DB<2> n
IPC::Run::_write(/usr/share/perl5/IPC/Run.pm:1413):
1413:	   my $r = POSIX::write( $_[0], $_[1], length $_[1] );
   DB<2> x @_
0  11
1  0
   DB<3> c

2014-05-03 12:52:09 dpchrist at dev ~/sandbox/perl
$