perldelta - what is new for perl v5.8.1 This document describes differences between the 5.8.0 release and the 5.8.1 release.

Tied Arrays with Negative Array Indices
Formerly, the indices passed to "FETCH", "STORE", "EXISTS", and "DELETE" methods in tied array class were always non-negative. If the actual argument was negative, Perl would call FETCHSIZE implicitly and add the result to the index before passing the result to the tied array method. This behavior is now optional. If the tied array class contains a package variable named $NEGATIVE_INDICES which is set to a true value, negative values will be passed to "FETCH", "STORE", "EXISTS", and "DELETE" unchanged.

Warnings
Perl 5.8.0 forgot to add some deprecation warnings. These warnings have now been added.

Pseudo-hashes really are deprecated
Pseudo-hashes were deprecated in Perl 5.8.0 and will be removed in Perl 5.10.0, see perl58delta for details. Each attempt to access pseudo-hashes will trigger the warning "Pseudo-hashes are deprecated". If you really want to continue using pseudo-hashes but not to see the deprecation warnings, add: no warnings 'deprecated';

5.005-style threads really are deprecated
5.005-style threads (activated by "use Thread;") were deprecated in Perl 5.8.0 and will be removed in Perl 5.10.0, see perl58delta for details. Each attempt to create a 5.005-style thread will trigger the warning "5.005 threads are deprecated". If you really want to continue using 5.005 threads but not to see the deprecation warnings, add: no warnings 'deprecated'; 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.com/ , 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. 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.