5 perl5203delta - what is new for perl v5.20.3
9 This document describes differences between the 5.20.2 release and the 5.20.3
12 If you are upgrading from an earlier release such as 5.20.1, first read
13 L<perl5202delta>, which describes differences between 5.20.1 and 5.20.2.
15 =head1 Incompatible Changes
17 There are no changes intentionally incompatible with 5.20.2. If any exist,
18 they are bugs, and we request that you submit a report. See L</Reporting Bugs>
21 =head1 Modules and Pragmata
23 =head2 Updated Modules and Pragmata
29 L<Errno> has been upgraded from version 1.20_05 to 1.20_06.
31 Add B<-P> to the pre-processor command-line on GCC 5. GCC added extra line
32 directives, breaking parsing of error code definitions.
33 L<[perl #123784]|https://rt.perl.org/Ticket/Display.html?id=123784>
37 L<Module::CoreList> has been upgraded from version 5.20150214 to 5.20150822.
39 Updated to cover the latest releases of Perl.
43 L<perl5db.pl> has been upgraded from 1.44 to 1.44_01.
45 The debugger would cause an assertion failure.
46 L<[perl #124127]|https://rt.perl.org/Ticket/Display.html?id=124127>
52 =head2 Changes to Existing Documentation
60 Mention that L<C<study()>|perlfunc/study> is currently a no-op.
70 The OOK example has been updated to account for COW changes and a change in the
71 storage of the offset.
75 =head3 L<perlhacktips>
81 Documentation has been added illustrating the perils of assuming the contents
82 of static memory pointed to by the return values of Perl wrappers for C library
83 functions doesn't change.
93 The specification of the POD language is changing so that the default encoding
94 of PODs that aren't in UTF-8 (unless otherwise indicated) is CP1252 instead of
99 =head1 Utility Changes
107 B<h2ph> now handles hexadecimal constants in the compiler's predefined macro
108 definitions, as visible in C<$Config{cppsymbols}>.
109 L<[perl #123784]|https://rt.perl.org/Ticket/Display.html?id=123784>
119 F<t/perf/taint.t> has been added to see if optimisations with taint issues are
124 F<t/porting/re_context.t> has been added to test that L<utf8> and its
125 dependencies only use the subset of the C<$1..$n> capture vars that
126 Perl_save_re_context() is hard-coded to localize, because that function has no
127 efficient way of determining at runtime what vars to localize.
131 =head1 Platform Support
133 =head2 Platform-Specific Notes
143 Previously, when compiling with a 64-bit Visual C++, every Perl XS module
144 (including CPAN ones) and Perl aware C file would unconditionally have around a
145 dozen warnings from F<hv_func.h>. These warnings have been silenced. GCC (all
146 bitness) and 32-bit Visual C++ were not affected.
150 B<miniperl.exe> is now built with B<-fno-strict-aliasing>, allowing 64-bit
151 builds to complete with GCC 4.8.
152 L<[perl #123976]|https://rt.perl.org/Ticket/Display.html?id=123976>
158 =head1 Selected Bug Fixes
164 Repeated global pattern matches in scalar context on large tainted strings were
165 exponentially slow depending on the current match position in the string.
166 L<[perl #123202]|https://rt.perl.org/Ticket/Display.html?id=123202>
170 The original visible value of L<C<$E<sol>>|perlvar/$E<sol>> is now preserved
171 when it is set to an invalid value. Previously if you set C<$/> to a reference
172 to an array, for example, perl would produce a runtime error and not set PL_rs,
173 but Perl code that checked C<$/> would see the array reference.
174 L<[perl #123218]|https://rt.perl.org/Ticket/Display.html?id=123218>
178 Perl 5.14.0 introduced a bug whereby C<eval { LABEL: }> would crash. This has
180 L<[perl #123652]|https://rt.perl.org/Ticket/Display.html?id=123652>
184 Extending an array cloned from a parent thread could result in "Modification of
185 a read-only value attempted" errors when attempting to modify the new elements.
186 L<[perl #124127]|https://rt.perl.org/Ticket/Display.html?id=124127>
190 Several cases of data used to store environment variable contents in core C
191 code being potentially overwritten before being used have been fixed.
192 L<[perl #123748]|https://rt.perl.org/Ticket/Display.html?id=123748>
196 UTF-8 variable names used in array indexes, unquoted UTF-8 HERE-document
197 terminators and UTF-8 function names all now work correctly.
198 L<[perl #124113]|https://rt.perl.org/Ticket/Display.html?id=124113>
202 A subtle bug introduced in Perl 5.20.2 involving UTF-8 in regular expressions
203 and sometimes causing a crash has been fixed. A new test script has been added
204 to test this fix; see under L</Testing>.
205 L<[perl #124109]|https://rt.perl.org/Ticket/Display.html?id=124109>
209 Some patterns starting with C</.*..../> matched against long strings have been
210 slow since Perl 5.8, and some of the form C</.*..../i> have been slow since
211 Perl 5.18. They are now all fast again.
212 L<[perl #123743]|https://rt.perl.org/Ticket/Display.html?id=123743>
216 Warning fatality is now ignored when rewinding the stack. This prevents
217 infinite recursion when the now fatal error also causes rewinding of the stack.
218 L<[perl #123398]|https://rt.perl.org/Ticket/Display.html?id=123398>
222 C<setpgrp($nonzero)> (with one argument) was accidentally changed in Perl 5.16
223 to mean C<setpgrp(0)>. This has been fixed.
227 A crash with C<< %::=(); J->${\"::"} >> has been fixed.
228 L<[perl #125541]|https://rt.perl.org/Ticket/Display.html?id=125541>
232 Regular expression possessive quantifier Perl 5.20 regression now fixed.
233 C<qr/>I<PAT>C<{>I<min>,I<max>C<}+>C</> is supposed to behave identically to
234 C<qr/(?E<gt>>I<PAT>C<{>I<min>,I<max>C<})/>. Since Perl 5.20, this didn't work
235 if I<min> and I<max> were equal.
236 L<[perl #125825]|https://rt.perl.org/Ticket/Display.html?id=125825>
240 Code like C</$a[/> used to read the next line of input and treat it as though
241 it came immediately after the opening bracket. Some invalid code consequently
242 would parse and run, but some code caused crashes, so this is now disallowed.
243 L<[perl #123712]|https://rt.perl.org/Ticket/Display.html?id=123712>
247 =head1 Acknowledgements
249 Perl 5.20.3 represents approximately 7 months of development since Perl 5.20.2
250 and contains approximately 3,200 lines of changes across 99 files from 26
253 Excluding auto-generated files, documentation and release tools, there were
254 approximately 1,500 lines of changes to 43 .pm, .t, .c and .h files.
256 Perl continues to flourish into its third decade thanks to a vibrant community
257 of users and developers. The following people are known to have contributed
258 the improvements that became Perl 5.20.3:
260 Alex Vandiver, Andy Dougherty, Aristotle Pagaltzis, Chris 'BinGOs' Williams,
261 Craig A. Berry, Dagfinn Ilmari Mannsåker, Daniel Dragan, David Mitchell,
262 Father Chrysostomos, H.Merijn Brand, James E Keenan, James McCoy, Jarkko
263 Hietaniemi, Karen Etheridge, Karl Williamson, kmx, Lajos Veres, Lukas Mai,
264 Matthew Horsfall, Petr Písař, Randy Stauner, Ricardo Signes, Sawyer X, Steve
265 Hay, Tony Cook, Yves Orton.
267 The list above is almost certainly incomplete as it is automatically generated
268 from version control history. In particular, it does not include the names of
269 the (very much appreciated) contributors who reported issues to the Perl bug
272 Many of the changes included in this version originated in the CPAN modules
273 included in Perl's core. We're grateful to the entire CPAN community for
274 helping Perl to flourish.
276 For a more complete list of all of Perl's historical contributors, please see
277 the F<AUTHORS> file in the Perl source distribution.
279 =head1 Reporting Bugs
281 If you find what you think is a bug, you might check the articles recently
282 posted to the comp.lang.perl.misc newsgroup and the perl bug database at
283 https://rt.perl.org/ . There may also be information at
284 http://www.perl.org/ , the Perl Home Page.
286 If you believe you have an unreported bug, please run the L<perlbug> program
287 included with your release. Be sure to trim your bug down to a tiny but
288 sufficient test case. Your bug report, along with the output of C<perl -V>,
289 will be sent off to perlbug@perl.org to be analysed by the Perl porting team.
291 If the bug you are reporting has security implications, which make it
292 inappropriate to send to a publicly archived mailing list, then please send it
293 to perl5-security-report@perl.org. This points to a closed subscription
294 unarchived mailing list, which includes all the core committers, who will be
295 able to help assess the impact of issues, figure out a resolution, and help
296 co-ordinate the release of patches to mitigate or fix the problem across all
297 platforms on which Perl is supported. Please only use this address for
298 security issues in the Perl core, not for modules independently distributed on
303 The F<Changes> file for an explanation of how to view exhaustive details on
306 The F<INSTALL> file for how to build Perl.
308 The F<README> file for general stuff.
310 The F<Artistic> and F<Copying> files for copyright information.