[perl #112826] Tie::StdHandle read() offset argument

# New Ticket Created by  Kevin Ryde 
# Please include the string:  [perl #112826]
# in the subject line of all future correspondence about this issue. 
# <URL: https://rt.perl.org:443/rt3/Ticket/Display.html?id=112826 >


With debian packaged perl 5.14.2 and Tie::StdHandle version 4.2, the
"offset" argument to read() is not obeyed by a tied handle.  For example
foo.pl

    use strict;
    use Tie::StdHandle;
    {
      open PP, '</dev/null';
      my $buf = "xxxxxxxxxx\n";
      read PP, $buf, 2, 5;
      print "plain:     \"$buf\"\n";
    }
    {
      tie *TT, 'Tie::StdHandle', '</dev/null';
      my $buf = "xxxxxxxxxx\n";
      read TT, $buf, 2, 5;
      print "StdHandle: \"$buf\"\n";
    }
    exit 0;

prints

    plain:     "xxxxx"
    StdHandle: ""

where I expected StdHandle to leave $buf as "xxxxx" the same as a plain
handle.

Perhaps the READ method should notice an offset argument and pass it on
to the real read().  I get some joy from the following.  Prototyping
prevents passing @_ directly does it?, the same as done in OPEN().

sub READ {
  (@_ > 3
   ? read($_[0],$_[1],$_[2],$_[3])
   : read($_[0],$_[1],$_[2]))
}




[Please do not change anything below this line]
-----------------------------------------------------------------
---
Flags:
    category=library
    severity=medium
    module=Tie::StdHandle
---
Site configuration information for perl 5.14.2:

Configured by Debian Project at Sat Mar  3 16:40:46 UTC 2012.

Summary of my perl5 (revision 5 version 14 subversion 2) configuration:
   
  Platform:
    osname=linux, osvers=2.6.32-5-686-bigmem, archname=i486-linux-gnu-thread-multi-64int
    uname='linux murphy 2.6.32-5-686-bigmem #1 smp mon jan 16 16:42:05 utc 2012 i686 gnulinux '
    config_args='-Dusethreads -Duselargefiles -Dccflags=-DDEBIAN -D_FORTIFY_SOURCE=2 -g -O2 -fstack-protector --param=ssp-buffer-size=4 -Wformat -Wformat-security -Werror=format-security -Dldflags= -Wl,-z,relro -Dlddlflags=-shared -Wl,-z,relro -Dcccdlflags=-fPIC -Darchname=i486-linux-gnu -Dprefix=/usr -Dprivlib=/usr/share/perl/5.14 -Darchlib=/usr/lib/perl/5.14 -Dvendorprefix=/usr -Dvendorlib=/usr/share/perl5 -Dvendorarch=/usr/lib/perl5 -Dsiteprefix=/usr/local -Dsitelib=/usr/local/share/perl/5.14.2 -Dsitearch=/usr/local/lib/perl/5.14.2 -Dman1dir=/usr/share/man/man1 -Dman3dir=/usr/share/man/man3 -Dsiteman1dir=/usr/local/man/man1 -Dsiteman3dir=/usr/local/man/man3 -Duse64bitint -Dman1ext=1 -Dman3ext=3perl -Dpager=/usr/bin/sensible-pager -Uafs -Ud_csh -Ud_ualarm -Uusesfio -Uusenm -Ui_libutil -DDEBUGGING=-g -Doptimize=-O2 -Duseshrplib -Dlibperl=libperl.so.5.14.2 -des'
    hint=recommended, useposix=true, d_sigaction=define
    useithreads=define, usemultiplicity=define
    useperlio=define, d_sfio=undef, uselargefiles=define, usesocks=undef
    use64bitint=define, use64bitall=undef, uselongdouble=undef
    usemymalloc=n, bincompat5005=undef
  Compiler:
    cc='cc', ccflags ='-D_REENTRANT -D_GNU_SOURCE -DDEBIAN -fstack-protector -fno-strict-aliasing -pipe -I/usr/local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64',
    optimize='-O2 -g',
    cppflags='-D_REENTRANT -D_GNU_SOURCE -DDEBIAN -fstack-protector -fno-strict-aliasing -pipe -I/usr/local/include'
    ccversion='', gccversion='4.6.2', 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='cc', ldflags =' -fstack-protector -L/usr/local/lib'
    libpth=/usr/local/lib /lib/i386-linux-gnu /lib/../lib /usr/lib/i386-linux-gnu /usr/lib/../lib /lib /usr/lib
    libs=-lgdbm -lgdbm_compat -ldb -ldl -lm -lpthread -lc -lcrypt
    perllibs=-ldl -lm -lpthread -lc -lcrypt
    libc=, so=so, useshrplib=true, libperl=libperl.so.5.14.2
    gnulibc_version='2.13'
  Dynamic Linking:
    dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags='-Wl,-E'
    cccdlflags='-fPIC', lddlflags='-shared -L/usr/local/lib -fstack-protector'

Locally applied patches:

• [perl #112826] Tie::StdHandle read() offset argument by Kevin Ryde