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[perl #119927] say TIED does not localize $\ as it claims
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From:
Ricardo SIGNES
Date:
September 21, 2013 05:47
Subject:
[perl #119927] say TIED does not localize $\ as it claims
Message ID:
rt-3.6.HEAD-1873-1379742423-339.119927-75-0@perl.org
# New Ticket Created by Ricardo SIGNES
# Please include the string: [perl #119927]
# in the subject line of all future correspondence about this issue.
# <URL: https://rt.perl.org:443/rt3/Ticket/Display.html?id=119927 >
This is a bug report for perl from rjbs@cpan.org,
generated with the help of perlbug 1.39 running under perl 5.16.3.
-----------------------------------------------------------------
[Please describe your issue here]
According to perlfunc, say is:
Just like "print", but implicitly appends a newline. "say LIST" is
simply an abbreviation for "{ local $\ = "\n"; print LIST }".
In the past, though, $\ was not updated. This was #49264
https://rt.perl.org/rt3/Ticket/Display.html?id=49264
It seems that the code to fix that, though, only restores $\ *if it was
defined* first. If $\ was undef, then it remains "\n" after the say, with
irritating consequences.
Here is a demonstration:
#!perl
use strict;
use warnings;
use feature 'say';
use Symbol;
package TiedHandle {
sub TIEHANDLE {
my ($class, $arg) = @_;
return bless {} => $class;
}
sub PRINT {
my ($self, @output) = @_;
no warnings 'uninitialized';
printf "# inside say, \$\\ is U+%04x\n", ord($\);
return 1;
}
}
my $fh_B = Symbol::gensym;
tie *$fh_B, 'TiedHandle';
print "$]\n";
{
no warnings 'uninitialized';
printf "# outside say, \$\\ is U+%04x\n", ord($\);
say $fh_B "foo"; # do say before print to detect bug
printf "# outside say, \$\\ is U+%04x\n", ord($\);
}
{
no warnings 'uninitialized';
$\ = "!";
printf "# outside say, \$\\ is U+%04x\n", ord($\);
say $fh_B "foo"; # do say before print to detect bug
printf "# outside say, \$\\ is U+%04x\n", ord($\);
}
This was fixed in 5.18.0, but not on purpose, as far as I can tell, because it
was fixed by:
commit 4bac9ae47b5ad7845a24e26b0e95609805de688a
Author: Chip Salzenberg <chip@pobox.com>
Date: Fri Jun 22 15:18:18 2012 -0700
Magic flags harmonization.
So, the question is: do we want to backport a fix to 5.16.x?
Either way, I will add a test to t/op/tiehandle.t to assert that this behaves
correctly with an uninitialized $\.
[Please do not change anything below this line]
-----------------------------------------------------------------
---
Flags:
category=core
severity=high
---
Site configuration information for perl 5.16.3:
Configured by rjbs at Mon Mar 11 12:31:36 EDT 2013.
Summary of my perl5 (revision 5 version 16 subversion 3) configuration:
Platform:
osname=darwin, osvers=12.2.1, archname=darwin-2level
uname='darwin walrus.local 12.2.1 darwin kernel version 12.2.1: thu oct 18 16:32:48 pdt 2012; root:xnu-2050.20.9~2release_x86_64 x86_64 '
config_args='-de -Dprefix=/Users/rjbs/perl5/perlbrew/perls/16.3 -Aeval:scriptdir=/Users/rjbs/perl5/perlbrew/perls/16.3/bin'
hint=recommended, useposix=true, d_sigaction=define
useithreads=undef, usemultiplicity=undef
useperlio=define, d_sfio=undef, uselargefiles=define, usesocks=undef
use64bitint=define, use64bitall=define, uselongdouble=undef
usemymalloc=n, bincompat5005=undef
Compiler:
cc='cc', ccflags ='-fno-common -DPERL_DARWIN -fno-strict-aliasing -pipe -fstack-protector -I/usr/local/include -I/opt/local/include',
optimize='-O3',
cppflags='-fno-common -DPERL_DARWIN -fno-strict-aliasing -pipe -fstack-protector -I/usr/local/include -I/opt/local/include'
ccversion='', gccversion='4.2.1 Compatible Apple Clang 4.0 ((tags/Apple/clang-421.0.57))', 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='env MACOSX_DEPLOYMENT_TARGET=10.3 cc', ldflags =' -fstack-protector -L/usr/local/lib -L/opt/local/lib'
libpth=/usr/local/lib /opt/local/lib /usr/lib
libs=-lgdbm -ldbm -ldl -lm -lutil -lc
perllibs=-ldl -lm -lutil -lc
libc=, so=dylib, useshrplib=false, libperl=libperl.a
gnulibc_version=''
Dynamic Linking:
dlsrc=dl_dlopen.xs, dlext=bundle, d_dlsymun=undef, ccdlflags=' '
cccdlflags=' ', lddlflags=' -bundle -undefined dynamic_lookup -L/usr/local/lib -L/opt/local/lib -fstack-protector'
Locally applied patches:
---
@INC for perl 5.16.3:
/Users/rjbs/.perlbrew/libs/16.3@std/lib/perl5/darwin-2level
/Users/rjbs/.perlbrew/libs/16.3@std/lib/perl5
/Users/rjbs/perl5/perlbrew/perls/16.3/lib/site_perl/5.16.3/darwin-2level
/Users/rjbs/perl5/perlbrew/perls/16.3/lib/site_perl/5.16.3
/Users/rjbs/perl5/perlbrew/perls/16.3/lib/5.16.3/darwin-2level
/Users/rjbs/perl5/perlbrew/perls/16.3/lib/5.16.3
.
---
Environment for perl 5.16.3:
DYLD_LIBRARY_PATH (unset)
HOME=/Users/rjbs
LANG=en_US.UTF-8
LANGUAGE (unset)
LD_LIBRARY_PATH (unset)
LOGDIR (unset)
PATH=/Users/rjbs/.perlbrew/libs/16.3@std/bin:/Users/rjbs/perl5/perlbrew/bin:/Users/rjbs/perl5/perlbrew/perls/16.3/bin:/Users/rjbs/bin:/opt/local/bin:/opt/local/sbin:/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin:/opt/X11/bin:/Users/rjbs/code/hla
PERL5LIB=/Users/rjbs/.perlbrew/libs/16.3@std/lib/perl5
PERLBREW_BASHRC_VERSION=0.63
PERLBREW_HOME=/Users/rjbs/.perlbrew
PERLBREW_LIB=std
PERLBREW_MANPATH=/Users/rjbs/.perlbrew/libs/16.3@std/man:/Users/rjbs/perl5/perlbrew/perls/16.3/man
PERLBREW_PATH=/Users/rjbs/.perlbrew/libs/16.3@std/bin:/Users/rjbs/perl5/perlbrew/bin:/Users/rjbs/perl5/perlbrew/perls/16.3/bin
PERLBREW_PERL=16.3
PERLBREW_ROOT=/Users/rjbs/perl5/perlbrew
PERLBREW_VERSION=0.63
PERLDOC=-n/opt/local/bin/groff
PERL_AUTOINSTALL=--skipdeps
PERL_BADLANG (unset)
PERL_LOCAL_LIB_ROOT=/Users/rjbs/.perlbrew/libs/16.3@std
PERL_MAILERS=sendmail:/Users/rjbs/bin/sendmail
PERL_MB_OPT=--install_base /Users/rjbs/.perlbrew/libs/16.3@std
PERL_MM_OPT=INSTALL_BASE=/Users/rjbs/.perlbrew/libs/16.3@std
SHELL=/opt/local/bin/zsh
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