| Subject: | [PATCH] Cwd.pm leaves $ENV{IFS} = undef on 5.6 |
Package: Cwd-2.21
----8<----
tanktest root # /opt/perl/bin/perl -V
Summary of my perl5 (revision 5.0 version 6 subversion 1) configuration:
Platform:
osname=freebsd, osvers=5.4-release, archname=i386-freebsd-thread-multi
uname='freebsd tanktest 5.4-release freebsd 5.4-release #0: tue jun 7 18:16:04 pdt 2005 neilw@tankpc05.tank:usrhomeneilwfreebsdtmp.objsophok i386 '
config_args='-des -Dcc=gcc -Dcf_by=Sophos -Dcf_email=PureMessage-Support@sophos.com -Dmyhostname=localhost -Dmydomain=localdomain -Uinstallusrbinperl -Ud_sigsetjmp -Ui_db -Dusethreads -Duseithreads -Accflags=-DPERL_DISABLE_PMC -Accflags=-DPMX_BUILD=150000 -Dprefix=/opt/perl'
hint=recommended, useposix=true, d_sigaction=define
usethreads=define use5005threads=undef useithreads=define usemultiplicity=define
useperlio=undef d_sfio=undef uselargefiles=define usesocks=undef
use64bitint=undef use64bitall=undef uselongdouble=undef
Compiler:
cc='gcc', ccflags ='-DPERL_DISABLE_PMC -DPMX_BUILD=150000 -fno-strict-aliasing',
optimize='-O',
cppflags='-DPERL_DISABLE_PMC -DPMX_BUILD=150000 -fno-strict-aliasing'
ccversion='', gccversion='3.4.2 [FreeBSD] 20040728', gccosandvers=''
intsize=4, longsize=4, ptrsize=4, doublesize=8, byteorder=1234
d_longlong=define, longlongsize=8, d_longdbl=define, longdblsize=12
ivtype='long', ivsize=4, nvtype='double', nvsize=8, Off_t='off_t', lseeksize=8
alignbytes=4, usemymalloc=n, prototype=define
Linker and Libraries:
ld='gcc', ldflags ='-pthread -Wl,-E '
libpth=/usr/lib
libs=-ldb -lm -lc_r -lcrypt -lutil
perllibs=-lm -lc_r -lcrypt -lutil
libc=, so=so, useshrplib=false, libperl=libperl.a
Dynamic Linking:
dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags=' '
cccdlflags='-DPIC -fpic', lddlflags='-shared '
Characteristics of this binary (from libperl):
Compile-time options: MULTIPLICITY USE_ITHREADS USE_LARGE_FILES PERL_IMPLICIT_CONTEXT
Locally applied patches:
ActivePerl Build 635 [PureMessage-Perl build 150000]
Built under freebsd
Compiled at Jun 13 2005 22:33:25
@INC:
/opt/perl/lib/5.6.1/i386-freebsd-thread-multi
/opt/perl/lib/5.6.1
/opt/perl/lib/site_perl/5.6.1/i386-freebsd-thread-multi
/opt/perl/lib/site_perl/5.6.1
/opt/perl/lib/site_perl
.
tanktest root # uname -a
FreeBSD tanktest 5.4-RELEASE FreeBSD 5.4-RELEASE #0: Tue Jun 7 18:16:04 PDT 2005 neilw@tankpc05.tank:/usr/home/neilw/freebsd/tmp.obj/SOPHOK i386
---->8----
The problem is in _backtick_pwd():
----8<----
# The 'natural and safe form' for UNIX (pwd may be setuid root)
sub _backtick_pwd {
local @ENV{qw(PATH IFS CDPATH ENV BASH_ENV)};
my $cwd = `$pwd_cmd`;
# Belt-and-suspenders in case someone said "undef $/".
local $/ = "\n";
# `pwd` may fail e.g. if the disk is full
chomp($cwd) if defined $cwd;
$cwd;
}
---->8----
Unfortunately, on Perl 5.6.1 (at least the version I'm using here), this leaves %ENV corrupted. To reproduce, try this one-liner:
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tanktest root # perl -MCwd -MData::Dumper -e 'print Dumper(\%ENV); cwd; print Dumper(\%ENV)'
$VAR1 = {
'_' => '/opt/perl/bin/perl',
'HISTFILESIZE' => '5000',
'STY' => '29048.autobld',
'SHLVL' => '3',
'HISTSIZE' => '5000',
'PWD' => '/root',
'INPUTRC' => '/etc/inputrc',
'PS1' => '\\[\\033[01;31m\\]\\h \\[\\033[01;34m\\]\\W \\$ \\[\\033[00m\\]',
'PAGER' => '/usr/bin/less',
'EDITOR' => '/usr/bin/vim',
'USER' => 'root',
'HOME' => '/root',
'OLDPWD' => '/opt/devel/lib',
'HISTFILE' => '/root/.bash_history',
'TERM' => 'screen-bce',
'LOGNAME' => 'root',
'PATH' => '/opt/devel/lib/ccache/bin:/bin:/sbin:/usr/bin:/usr/sbin:/opt/devel/bin',
'HISTCONTROL' => 'ignoredups',
'SHELL' => '/bin/bash',
'MAIL' => '/var/mail/root'
};
$VAR1 = {
'BASH_ENV' => undef,
'IFS' => undef,
'_' => '/opt/perl/bin/perl',
'HISTFILESIZE' => '5000',
'STY' => '29048.autobld',
'CDPATH' => undef,
'SHLVL' => '3',
'ENV' => undef,
'HISTSIZE' => '5000',
'PWD' => '/root',
'INPUTRC' => '/etc/inputrc',
'PS1' => '\\[\\033[01;31m\\]\\h \\[\\033[01;34m\\]\\W \\$ \\[\\033[00m\\]',
'PAGER' => '/usr/bin/less',
'EDITOR' => '/usr/bin/vim',
'USER' => 'root',
'HOME' => '/root',
'OLDPWD' => '/opt/devel/lib',
'HISTFILE' => '/root/.bash_history',
'TERM' => 'screen-bce',
'LOGNAME' => 'root',
'PATH' => '/opt/devel/lib/ccache/bin:/bin:/sbin:/usr/bin:/usr/sbin:/opt/devel/bin',
'HISTCONTROL' => 'ignoredups',
'SHELL' => '/bin/bash',
'MAIL' => '/var/mail/root'
};
---->8----
Notice the $ENV{IFS} = undef? That's naughty. That actually sets $IFS, the input field separator, for subsequently launched /bin/sh programs.
Here's a simple patch that fixes the problem:
----8<----
--- Cwd.pm~ 2005/05/05 11:07:31
+++ Cwd.pm 2005/06/14 11:08:07
@@ -292,7 +292,8 @@
# The 'natural and safe form' for UNIX (pwd may be setuid root)
sub _backtick_pwd {
- local @ENV{qw(PATH IFS CDPATH ENV BASH_ENV)};
+ my @localize = grep exists $ENV{$_}, qw(PATH IFS CDPATH ENV BASH_ENV);
+ local @ENV{@localize};
my $cwd = `$pwd_cmd`;
# Belt-and-suspenders in case someone said "undef $/".
local $/ = "\n";
---->8----
Cheers,
Neil