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
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++
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 temporary
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
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.
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".
"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.
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 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/
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.