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read() on a write-only filehandle corrupts a later print() #13294

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p5pRT opened this issue Sep 20, 2013 · 5 comments
Closed

read() on a write-only filehandle corrupts a later print() #13294

p5pRT opened this issue Sep 20, 2013 · 5 comments
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distro-Linux type-core

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@p5pRT
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p5pRT commented Sep 20, 2013

Migrated from rt.perl.org#119923 (status was 'open')

Searchable as RT119923$
@p5pRT
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p5pRT commented Sep 20, 2013

From felipe@cpanel.net

Created by felipe@cpanel.net

Run the code below​:
------------------
#!/usr/bin/perl -w

use strict;

use File​::Temp ();

my ( undef, $tfile ) = File​::Temp​::tempfile();

open my $tfh, '>', $tfile or die $!;

#This "corrupts" the file handle and produces the spurious print() failures,
#even though the buffer is actually written to the file.
eval { local $!; read $tfh, my $buffer, 50 };

print {$tfh} 'haha' or warn "print() failed​:$!|\n";

print "Contents​:" . `cat $tfile` . "|\n" or die $!;
-----------------

...and notice that the first print() returns a failure, even though it
does actually complete its work, as shown by the final print() to STDOUT.

If you take out the read(), this problem goes away.

Perl Info 

Flags:
    category=core
    severity=low

Site configuration information for perl 5.14.3:

Configured by cPanel at Tue Mar  5 15:43:05 CST 2013.

Summary of my perl5 (revision 5 version 14 subversion 3) configuration:
   
  Platform:
    osname=linux, osvers=2.6.32-220.17.1.el6.i686, archname=i386-linux-64int
    uname='linux rpmb-32-centos-6 2.6.32-220.17.1.el6.i686 #1 smp tue may 15 22:09:39 bst 2012 i686 i686 i386 gnulinux '
    config_args='-des -Dusedevel -Darchname=i386-linux-64int -Dcc=/usr/bin/gcc -Dcpp=/usr/bin/cpp -DDEBUGGING=none -Doptimize=-Os -Dusemymalloc=n -Duseshrplib -Duselargefiles=yes -Duseposix=true -Dhint=recommended -Duseperlio=yes -Dccflags=-I/usr/local/cpanel/3rdparty/perl/514/include -L/usr/local/cpanel/3rdparty/perl/514/lib -I/usr/local/cpanel/3rdparty/include -L/usr/local/cpanel/3rdparty/lib -DAPPLLIB_EXP="/usr/local/cpanel" -Dcppflags=-I/usr/local/cpanel/3rdparty/perl/514/include -L/usr/local/cpanel/3rdparty/perl/514/lib -I/usr/local/cpanel/3rdparty/include -L/usr/local/cpanel/3rdparty/lib -Dldflags=-Wl,-rpath -Wl,/usr/local/cpanel/3rdparty/perl/514/lib -L/usr/local/cpanel/3rdparty/perl/514/lib -L/usr/local/cpanel/3rdparty/lib -Dprefix=/usr/local/cpanel/3rdparty/perl/514 -Dsiteprefix=/opt/cpanel/perl5/514 -Dsitebin=/opt/cpanel/perl5/514/bin -Dsitelib=/opt/cpanel/perl5/514/site_lib -Dusevendorprefix=true -Dvendorbin=/usr/local/cpanel/3rdparty/perl/514/bin -Dvendorprefix=/usr/local/cpanel/3rdparty/perl/514/lib/perl5 -Dvendorlib=/usr/local/cpanel/3rdparty/perl/514/lib/perl5/cpanel_lib -Dprivlib=/usr/local/cpanel/3rdparty/perl/514/lib/perl5/5.14.3 -Dman1dir=none -Dman3dir=none -Dscriptdir=/usr/local/cpanel/3rdparty/perl/514/bin -Dscriptdirexp=/usr/local/cpanel/3rdparty/perl/514/bin -Dsiteman1dir=none -Dsiteman3dir=none -Dinstallman1dir=none -Dversiononly=no -Dinstallusrbinperl=no -Dcf_by=cPanel -Dmyhostname=localhost -Dperladmin=root@localhost -Dcf_email=support@cpanel.net -Di_dbm=/usr/local/cpanel/3rdparty/include -Di_gdbm=/usr/local/cpanel/3rdparty/include -Di_ndbm=/usr/local/cpanel/3rdparty/include -Ud_dosuid -Uuserelocatableinc -Umad -Uusethreads -Uusemultiplicity -Uusesocks -Uuselongdouble -Ui_db -Aldflags=-L/usr/local/cpanel/3rdparty/perl/514/lib -L/usr/local/cpanel/3rdparty/lib -L/usr/lib -L/lib -lgdbm -Dlocincpth=/usr/local/cpanel/3rdparty/perl/514/include /usr/local/cpanel/3rdparty/include /usr/local/include  -Duse64bitint -Uuse64bitall -Acflags=-fPIC -DPIC -m32 -I/usr/local/cpanel/3rdparty/perl/514/include -I/usr/local/cpanel/3rdparty/include -Dlibpth=/usr/local/cpanel/3rdparty/perl/514/lib /usr/local/cpanel/3rdparty/lib /usr/local/lib /lib /usr/lib '
    hint=recommended, useposix=true, d_sigaction=define
    useithreads=undef, usemultiplicity=undef
    useperlio=define, d_sfio=undef, uselargefiles=define, usesocks=undef
    use64bitint=define, use64bitall=undef, uselongdouble=undef
    usemymalloc=n, bincompat5005=undef
  Compiler:
    cc='/usr/bin/gcc', ccflags ='-I/usr/local/cpanel/3rdparty/perl/514/include -L/usr/local/cpanel/3rdparty/perl/514/lib -I/usr/local/cpanel/3rdparty/include -L/usr/local/cpanel/3rdparty/lib -DAPPLLIB_EXP="/usr/local/cpanel" -fno-strict-aliasing -pipe -fstack-protector -I/usr/local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64',
    optimize='-Os',
    cppflags='-I/usr/local/cpanel/3rdparty/perl/514/include -L/usr/local/cpanel/3rdparty/perl/514/lib -I/usr/local/cpanel/3rdparty/include -L/usr/local/cpanel/3rdparty/lib -I/usr/local/cpanel/3rdparty/perl/514/include -L/usr/local/cpanel/3rdparty/perl/514/lib -I/usr/local/cpanel/3rdparty/include -L/usr/local/cpanel/3rdparty/lib -DAPPLLIB_EXP="/usr/local/cpanel" -fno-strict-aliasing -pipe -fstack-protector -I/usr/local/include'
    ccversion='', gccversion='4.4.6 20110731 (Red Hat 4.4.6-3)', gccosandvers=''
    intsize=4, longsize=4, ptrsize=4, doublesize=8, byteorder=12345678
    d_longlong=define, longlongsize=8, d_longdbl=define, longdblsize=12
    ivtype='long long', ivsize=8, nvtype='double', nvsize=8, Off_t='off_t', lseeksize=8
    alignbytes=4, prototype=define
  Linker and Libraries:
    ld='/usr/bin/gcc', ldflags ='-Wl,-rpath -Wl,/usr/local/cpanel/3rdparty/perl/514/lib -L/usr/local/cpanel/3rdparty/perl/514/lib -L/usr/local/cpanel/3rdparty/lib -L/usr/local/cpanel/3rdparty/perl/514/lib -L/usr/local/cpanel/3rdparty/lib -L/usr/lib -L/lib -lgdbm -fstack-protector -L/usr/local/lib'
    libpth=/usr/local/lib /lib /usr/lib
    libs=-lnsl -lgdbm -ldb -ldl -lm -lcrypt -lutil -lc
    perllibs=-lnsl -ldl -lm -lcrypt -lutil -lc
    libc=/lib/libc-2.12.so, so=so, useshrplib=true, libperl=libperl.so
    gnulibc_version='2.12'
  Dynamic Linking:
    dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags='-Wl,-E -Wl,-rpath,/usr/local/cpanel/3rdparty/perl/514/lib/perl5/5.14.3/i386-linux-64int/CORE'
    cccdlflags='-fPIC', lddlflags='-shared -Os -L/usr/local/cpanel/3rdparty/perl/514/lib -L/usr/local/cpanel/3rdparty/lib -L/usr/lib -L/lib -L/usr/local/lib -fstack-protector'

Locally applied patches:
    cPanel patches
    cPanel INC path changes
    Disabled some unstable tests on a kvm build server
    Cherry pick of 49498ca from p5p (RT 113514)


@INC for perl 5.14.3:
    /usr/local/cpanel
    /usr/local/cpanel
    /usr/local/cpanel/3rdparty/perl/514/lib/perl5/cpanel_lib/i386-linux-64int
    /usr/local/cpanel/3rdparty/perl/514/lib/perl5/cpanel_lib
    /usr/local/cpanel/3rdparty/perl/514/lib/perl5/5.14.3/i386-linux-64int
    /usr/local/cpanel/3rdparty/perl/514/lib/perl5/5.14.3
    /opt/cpanel/perl5/514/site_lib/i386-linux-64int
    /opt/cpanel/perl5/514/site_lib
    .


Environment for perl 5.14.3:
    HOME=/root
    LANG=en_US.UTF-8
    LANGUAGE (unset)
    LD_LIBRARY_PATH (unset)
    LOGDIR (unset)
    PATH=/root/.opt/bin:/usr/local/cpanel/3rdparty/perl/514/bin:/usr/local/cpanel/3rdparty/bin:/usr/local/cpanel/3rdparty/node/bin:/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin
    PERL5LIB=/usr/local/cpanel
    PERL_BADLANG (unset)
    SHELL=/bin/bash

@p5pRT
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p5pRT commented Sep 25, 2013

From @shlomif

I am able to reproduce this bug with perl-5.18.1-2.mga4 on Mageia Linux
Cauldron (What will become Mageia 4). I am getting​:

shlomif@​telaviv1​:~$ perl Test.pl
Filehandle $tfh opened only for output at Test.pl line 13.
print() failed​:Inappropriate ioctl for device|
Contents​:haha|
shlomif@​telaviv1​:~$

Regards,

-- Shlomi Fish

@p5pRT
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p5pRT commented Sep 25, 2013

The RT System itself - Status changed from 'new' to 'open'

@p5pRT
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p5pRT commented Sep 29, 2013

From @Leont

On Sat, Sep 21, 2013 at 1​:01 AM, felipe@​cpanel.net <
perlbug-followup@​perl.org> wrote​:

Run the code below​:
------------------
#!/usr/bin/perl -w

use strict;

use File​::Temp ();

my ( undef, $tfile ) = File​::Temp​::tempfile();

open my $tfh, '>', $tfile or die $!;

#This "corrupts" the file handle and produces the spurious print()
failures,
#even though the buffer is actually written to the file.
eval { local $!; read $tfh, my $buffer, 50 };

print {$tfh} 'haha' or warn "print() failed​:$!|\n";

print "Contents​:" . `cat $tfile` . "|\n" or die $!;
-----------------

...and notice that the first print() returns a failure, even though it
does actually complete its work, as shown by the final print() to STDOUT.

If you take out the read(), this problem goes away.

This bug is a duplicate of #111352 and related to #108124. Actually it's
far worse that your example suggests​: it's only printing the first argument
to print, then it checks the error flag and aborts :-/.

Leon

@FGasper
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FGasper commented Jan 31, 2020

Per Leon’s last comment, this is a dupe. Closing.

@FGasper FGasper closed this as completed Jan 31, 2020
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