perl583delta - what is new for perl v5.8.3
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
There are no changes incompatible with 5.8.2.
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.
A function again
is provided to resolve problems where modules in different
directories wish to use FindBin.
You can now weaken references to read only values.
cond_wait
has a new two argument form. cond_timedwait
has been added.
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.
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.
Perl now builds on OpenVMS I64
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 therefore
$!
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++
The fatal error "DESTROY created new reference to dead object" is now documented in perldiag.
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 temporary local variables now name these variables more defensively, which should avoid bugs where names clash.
<signal.h> is now always included.
Configure
now invokes callbacks regardless of the value of the variable
they are called for. Previously callbacks were only invoked in the
case $variable $define) branch. This change should only affect platform
maintainers writing configuration hints files.
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.
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
. suidperl
is neither built nor installed by default, and has been deprecated 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.
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.
Iain 'Spoon' Truskett, Perl hacker, author of perlreref and contributor to CPAN, died suddenly on 29th December 2003, aged 24. He will be missed.
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
program 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/
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.