3 perl571delta - what's new for perl v5.7.2
7 This document describes differences between the 5.7.1 release and the
10 (To view the differences between the 5.6.0 release and the 5.7.0
11 release, see L<perl570delta>. To view the differences between the
12 5.7.0 release and the 5.7.1 release, see L<perl571delta>.)
14 =head1 Security Vulnerability Closed
16 (This change was already made in 5.7.0 but bears repeating here.)
18 A security vulnerability affecting all Perl versions prior to 5.6.1
19 was found in August 2000. The vulnerability does not affect default
20 installations and as far as is known affects only the Linux platform.
22 You should upgrade your Perl to 5.6.1 as soon as possible. Patches
23 for earlier releases exist but they require full recompilation from
24 the source code so 5.6.1 is your best choice.
25 See http://www.cpan.org/src/5.0/sperl-2000-08-05/sperl-2000-08-05.txt
28 =head1 Incompatible Changes
30 =head1 Future Deprecations
32 The current user-visible implementation of pseudo-hashes (the weird
33 use of the first array element) is deprecated starting from Perl 5.8.0
34 and will be removed in Perl 5.10.0, and the feature will be implemented
35 differently. Not only is the current interface rather ugly, but the
36 current implementation slows down normal array and hash use quite
37 noticeably. The 'fields' pragma interface will remain available.
39 =head1 Core Enhancements
41 =head1 Modules and Pragmata
45 =head2 Updated And Improved Modules and Pragmata
47 =head1 Performance Enhancements
49 =head1 Utility Changes
51 =head1 New Documentation
53 =head1 Installation and Configuration Improvements
55 =head2 New Or Improved Platforms
57 =head2 Generic Improvements
59 =head1 Selected Bug Fixes
61 =head2 Platform Specific Changes and Fixes
63 =head1 New or Changed Diagnostics
65 =head1 Changed Internals
67 =head2 Regex pre-/post-compilation items matched up
69 The regex compiler now maintains a structure that identifies nodes in
70 the compiled bytecode with the corresponding syntactic features of the
71 original regex expression. The information is attached to the new
72 C<offsets> member of the C<struct regexp>. See L<perldebguts> for more
79 Note that unlike other sections in this document (which describe
80 changes since 5.7.0) this section is cumulative containing known
81 problems for all the 5.7 releases.
83 =head2 AIX vac 5.0.0.0 May Produce Buggy Code For Perl
85 The AIX C compiler vac version 5.0.0.0 may produce buggy code,
86 resulting in few random tests failing, but when the failing tests
87 are run by hand, they succeed. We suggest upgrading to at least
88 vac version 5.0.1.0, that has been known to compile Perl correctly.
89 "lslpp -L|grep vac.C" will tell you the vac version.
91 =head2 lib/ftmp-security tests warn 'system possibly insecure'
93 Don't panic. Read INSTALL 'make test' section instead.
95 =head2 lib/io_multihomed Fails In LP64-Configured HP-UX
97 The lib/io_multihomed test may hang in HP-UX if Perl has been
98 configured to be 64-bit. Because other 64-bit platforms do not hang in
99 this test, HP-UX is suspect. All other tests pass in 64-bit HP-UX. The
100 test attempts to create and connect to "multihomed" sockets (sockets
101 which have multiple IP addresses).
103 =head2 Test lib/posix Subtest 9 Fails In LP64-Configured HP-UX
105 If perl is configured with -Duse64bitall, the successful result of the
106 subtest 10 of lib/posix may arrive before the successful result of the
107 subtest 9, which confuses the test harness so much that it thinks the
112 The test fails on various platforms (PA64 and IA64 are known), but the
113 exact cause is still being investigated.
115 =head2 Linux With Sfio Fails op/misc Test 48
119 =head2 sigaction test 13 in VMS
121 The test is known to fail; whether it's because of VMS of because
122 of faulty test is not known.
124 =head2 sprintf tests 129 and 130
126 The op/sprintf tests 129 and 130 are known to fail on some platforms.
127 Examples include any platform using sfio, and Compaq/Tandem's NonStop-UX.
128 The failing platforms do not comply with the ANSI C Standard, line
129 19ff on page 134 of ANSI X3.159 1989 to be exact. (They produce
130 something else than "1" and "-1" when formatting 0.6 and -0.6 using
131 the printf format "%.0f", most often they produce "0" and "-0".)
133 =head2 Failure of Thread tests
135 The subtests 19 and 20 of lib/thr5005.t test are known to fail due to
136 fundamental problems in the 5.005 threading implementation. These are
137 not new failures--Perl 5.005_0x has the same bugs, but didn't have
138 these tests. (Note that support for 5.005-style threading remains
141 =head2 Localising a Tied Variable Leaks Memory
144 tie my %tie_hash => 'Tie::StdHash';
148 local($tie_hash{Foo}) = 1; # leaks
150 Code like the above is known to leak memory every time the local()
153 =head2 Self-tying of Arrays and Hashes Is Forbidden
155 Self-tying of arrays and hashes is broken in rather deep and
156 hard-to-fix ways. As a stop-gap measure to avoid people from getting
157 frustrated at the mysterious results (core dumps, most often) it is
158 for now forbidden (you will get a fatal error even from an attempt).
160 =head2 Building Extensions Can Fail Because Of Largefiles
162 Some extensions like mod_perl are known to have issues with
163 `largefiles', a change brought by Perl 5.6.0 in which file offsets
164 default to 64 bits wide, where supported. Modules may fail to compile
165 at all or compile and work incorrectly. Currently there is no good
166 solution for the problem, but Configure now provides appropriate
167 non-largefile ccflags, ldflags, libswanted, and libs in the %Config
168 hash (e.g., $Config{ccflags_nolargefiles}) so the extensions that are
169 having problems can try configuring themselves without the
170 largefileness. This is admittedly not a clean solution, and the
171 solution may not even work at all. One potential failure is whether
172 one can (or, if one can, whether it's a good idea) link together at
173 all binaries with different ideas about file offsets, all this is
176 =head2 The Compiler Suite Is Still Experimental
178 The compiler suite is slowly getting better but is nowhere near
181 =head1 Reporting Bugs
183 If you find what you think is a bug, you might check the articles
184 recently posted to the comp.lang.perl.misc newsgroup and the perl
185 bug database at http://bugs.perl.org. There may also be
186 information at http://www.perl.com/perl/, the Perl Home Page.
188 If you believe you have an unreported bug, please run the B<perlbug>
189 program included with your release. Be sure to trim your bug down
190 to a tiny but sufficient test case. Your bug report, along with the
191 output of C<perl -V>, will be sent off to perlbug@perl.org to be
192 analysed by the Perl porting team.
196 The F<Changes> file for exhaustive details on what changed.
198 The F<INSTALL> file for how to build Perl.
200 The F<README> file for general stuff.
202 The F<Artistic> and F<Copying> files for copyright information.
206 Written by Jarkko Hietaniemi <F<jhi@iki.fi>>, with many contributions
207 from The Perl Porters and Perl Users submitting feedback and patches.
209 Send omissions or corrections to <F<perlbug@perl.org>>.