perl583delta



PERL583DELTA(1)        Perl Programmers Reference Guide        PERL583DELTA(1)




NAME

       perl583delta - what is new for perl v5.8.3


DESCRIPTION

       This document describes differences between the 5.8.2 release and the
       5.8.3 release.

       If you are upgrading from an earlier release such as 5.6.1, first read
       the perl58delta, which describes differences between 5.6.0 and 5.8.0,
       and the perl581delta and perl582delta, which describe differences
       between 5.8.0, 5.8.1 and 5.8.2


Incompatible Changes

       There are no changes incompatible with 5.8.2.


Core Enhancements

       A "SCALAR" method is now available for tied hashes. This is called when
       a tied hash is used in scalar context, such as

           if (%tied_hash) {
               ...
           }

       The old behaviour was that %tied_hash would return whatever would have
       been returned for that hash before the hash was tied (so usually 0).
       The new behaviour in the absence of a SCALAR method is to return TRUE
       if in the middle of an "each" iteration, and otherwise call FIRSTKEY to
       check if the hash is empty (making sure that a subsequent "each" will
       also begin by calling FIRSTKEY). Please see "SCALAR" in perltie for the
       full details and caveats.


Modules and Pragmata

       CGI
       Cwd
       Digest
       Digest::MD5
       Encode
       File::Spec
       FindBin
           A function "again" is provided to resolve problems where modules in
           different directories wish to use FindBin.

       List::Util
           You can now weaken references to read only values.

       Math::BigInt
       PodParser
       Pod::Perldoc
       POSIX
       Unicode::Collate
       Unicode::Normalize
       Test::Harness
       threads::shared
           "cond_wait" has a new two argument form. "cond_timedwait" has been
           added.


Utility Changes

       "find2perl" now assumes "-print" as a default action. Previously, it
       needed to be specified explicitly.

       A new utility, "prove", makes it easy to run an individual regression
       test at the command line. "prove" is part of Test::Harness, which users
       of earlier Perl versions can install from CPAN.


New Documentation

       The documentation has been revised in places to produce more standard
       manpages.

       The documentation for the special code blocks (BEGIN, CHECK, INIT, END)
       has been improved.


Installation and Configuration Improvements

       Perl now builds on OpenVMS I64


Selected Bug Fixes

       Using substr() on a UTF8 string could cause subsequent accesses on that
       string to return garbage. This was due to incorrect UTF8 offsets being
       cached, and is now fixed.

       join() could return garbage when the same join() statement was used to
       process 8 bit data having earlier processed UTF8 data, due to the flags
       on that statement’s temporary workspace not being reset correctly. This
       is now fixed.

       "$a .. $b" will now work as expected when either $a or $b is "undef"

       Using Unicode keys with tied hashes should now work correctly.

       Reading $^E now preserves $!. Previously, the C code implementing $^E
       did not preserve "errno", so reading $^E could cause "errno" and there-
       fore $! to change unexpectedly.

       Reentrant functions will (once more) work with C++. 5.8.2 introduced a
       bugfix which accidentally broke the compilation of Perl extensions
       written in C++


New or Changed Diagnostics

       The fatal error "DESTROY created new reference to dead object" is now
       documented in perldiag.


Changed Internals

       The hash code has been refactored to reduce source duplication. The
       external interface is unchanged, and aside from the bug fixes described
       above, there should be no change in behaviour.

       "hv_clear_placeholders" is now part of the perl API

       Some C macros have been tidied. In particular macros which create tem-
       porary local variables now name these variables more defensively, which
       should avoid bugs where names clash.

       <signal.h> is now always included.


Configuration and Building

       "Configure" now invokes callbacks regardless of the value of the vari-
       able they are called for. Previously callbacks were only invoked in the
       "case $variable $define)" branch. This change should only affect plat-
       form maintainers writing configuration hints files.


Platform Specific Problems

       The regression test ext/threads/shared/t/wait.t fails on early RedHat 9
       and HP-UX 10.20 due to bugs in their threading implementations.  RedHat
       users should see https://rhn.redhat.com/errata/RHBA-2003-136.html and
       consider upgrading their glibc.


Known Problems

       Detached threads aren’t supported on Windows yet, as they may lead to
       memory access violation problems.

       There is a known race condition opening scripts in "suidperl". "suid-
       perl" is neither built nor installed by default, and has been depre-
       cated since perl 5.8.0. You are advised to replace use of suidperl with
       tools such as sudo ( http://www.courtesan.com/sudo/ )

       We have a backlog of unresolved bugs. Dealing with bugs and bug reports
       is unglamorous work; not something ideally suited to volunteer labour,
       but that is all that we have.

       The perl5 development team are implementing changes to help address
       this problem, which should go live in early 2004.


Future Directions

       Code freeze for the next maintenance release (5.8.4) is on March 31st
       2004, with release expected by mid April. Similarly 5.8.5’s freeze will
       be at the end of June, with release by mid July.


Obituary

       Iain ’Spoon’ Truskett, Perl hacker, author of perlreref and contributor
       to CPAN, died suddenly on 29th December 2003, aged 24.  He will be
       missed.


Reporting Bugs

       If you find what you think is a bug, you might check the articles
       recently posted to the comp.lang.perl.misc newsgroup and the perl bug
       database at http://bugs.perl.org.  There may also be information at
       http://www.perl.org, the Perl Home Page.

       If you believe you have an unreported bug, please run the perlbug pro-
       gram included with your release.  Be sure to trim your bug down to a
       tiny but sufficient test case.  Your bug report, along with the output
       of "perl -V", will be sent off to perlbug@perl.org to be analysed by
       the Perl porting team.  You can browse and search the Perl 5 bugs at
       http://bugs.perl.org/


SEE ALSO

       The Changes file for exhaustive details on what changed.

       The INSTALL file for how to build Perl.

       The README file for general stuff.

       The Artistic and Copying files for copyright information.



perl v5.8.6                       2004-11-05                   PERL583DELTA(1)

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