5 perl5275delta - what is new for perl v5.27.5
9 This document describes differences between the 5.27.4 release and the 5.27.5
12 If you are upgrading from an earlier release such as 5.27.3, first read
13 L<perl5274delta>, which describes differences between 5.27.3 and 5.27.4.
15 =head1 Incompatible Changes
17 =head2 Subroutines no longer need typeglobs
19 Perl 5.22.0 introduced an optimization allowing subroutines to be stored in
20 packages as simple sub refs, not requiring a full typeglob (thus
21 potentially saving large amounts of memeory). However, the optimization
22 was flawed: it only applied to the main package.
24 This optimization has now been extended to all packages. This may break
25 compatibility with introspection code that looks inside stashes and expects
26 everything in them to be a typeglob.
28 When this optimization happens, the typeglob still notionally exists, so
29 accessing it will cause the stash entry to be upgraded to a typeglob. The
30 optimization does not apply to XSUBs or exported subroutines, and calling a
31 method will undo it, since method calls cache things in typeglobs.
33 [perl #129916] [perl #132252]
35 =head1 Performance Enhancements
41 Calls to C<require> for an already loaded module are now slightly faster.
42 L<[perl #132171]|https://rt.perl.org/Public/Bug/Display.html?id=132171>
46 =head1 Modules and Pragmata
48 =head2 Updated Modules and Pragmata
54 L<arybase> has been upgraded from version 0.13 to 0.14.
58 L<B> has been upgraded from version 1.69 to 1.70.
62 L<B::Concise> has been upgraded from version 1.001 to 1.002.
66 L<B::Deparse> has been upgraded from version 1.42 to 1.43.
70 L<Config::Perl::V> has been upgraded from version 0.28 to 0.29.
74 L<Digest::SHA> has been upgraded from version 5.96 to 5.98.
78 L<Encode> has been upgraded from version 2.92 to 2.93.
82 L<encoding> has been upgraded from version 2.20 to 2.21.
86 L<File::Fetch> has been upgraded from version 0.52 to 0.54.
90 L<File::Path> has been upgraded from version 2.14 to 2.15.
94 L<List::Util> has been upgraded from version 1.48 to 1.49.
98 L<Locale::Codes> has been upgraded from version 3.52 to 3.54.
102 L<Math::BigInt> has been upgraded from version 1.999806 to 1.999811.
106 L<Math::BigInt::FastCalc> has been upgraded from version 0.5005 to 0.5006.
110 L<Module::CoreList> has been upgraded from version 5.20170920 to 5.20171020.
114 L<NEXT> has been upgraded from version 0.67 to 0.67_01.
118 L<Pod::Perldoc> has been upgraded from version 3.28 to 3.2801.
122 L<POSIX> has been upgraded from version 1.77 to 1.78.
126 L<Scalar::Util> has been upgraded from version 1.48 to 1.49.
130 L<Sub::Util> has been upgraded from version 1.48 to 1.49.
134 L<Sys::Hostname> has been upgraded from version 1.20 to 1.21.
138 L<Test::Simple> has been upgraded from version 1.302073 to 1.302103.
142 L<Time::HiRes> has been upgraded from version 1.9743 to 1.9746.
146 L<Time::Piece> has been upgraded from version 1.3201 to 1.3202.
150 =head1 Platform Support
152 =head2 Platform-Specific Notes
158 Compilation on CentOS 5 is now fixed.
162 =head1 Selected Bug Fixes
168 Calling L<exec PROGRAM LIST|perlfunc/exec PROGRAM LIST> with an empty C<LIST>
169 has been fixed. This should call C<execvp()> with an empty C<argv> array
170 (containing only the terminating C<NULL> pointer), but was instead just
171 returning false (and not setting L<C<$!>|perlvar/$!>).
172 L<[perl #131730]|https://rt.perl.org/Public/Bug/Display.html?id=131730>
176 The C<gv_fetchmeth_sv> C function stopped working properly in Perl 5.22 when
177 fetching a constant with a UTF-8 name if that constant subroutine was stored in
178 the stash as a simple scalar reference, rather than a full typeglob. This has
183 Single-letter debugger commands followed by an argument which starts with
184 punctuation (e.g. C<p$^V> and C<x@ARGV>) now work again. They had been
185 wrongly requiring a space between the command and the argument.
186 L<[perl #120174]|https://rt.perl.org/Public/Bug/Display.html?id=120174>
190 L<splice|perlfunc/splice ARRAY,OFFSET,LENGTH,LIST> now throws an exception
191 ("Modification of a read-only value attempted") when modifying a read-only
192 array. Until now it had been silently modifying the array. The new behaviour
193 is consistent with the behaviour of L<push|perlfunc/push ARRAY,LIST> and
194 L<unshift|perlfunc/unshift ARRAY,LIST>.
195 L<[perl #131000]|https://rt.perl.org/Public/Bug/Display.html?id=131000>
199 =head1 Acknowledgements
201 Perl 5.27.5 represents approximately 4 weeks of development since Perl 5.27.4
202 and contains approximately 29,000 lines of changes across 430 files from 20
205 Excluding auto-generated files, documentation and release tools, there were
206 approximately 17,000 lines of changes to 340 .pm, .t, .c and .h files.
208 Perl continues to flourish into its third decade thanks to a vibrant community
209 of users and developers. The following people are known to have contributed
210 the improvements that became Perl 5.27.5:
212 Aaron Crane, Chris 'BinGOs' Williams, Craig A. Berry, Dagfinn Ilmari
213 Mannsåker, Dmitry Ulanov, Dominic Hargreaves, Father Chrysostomos, H.Merijn
214 Brand, James E Keenan, John P. Linderman, John SJ Anderson, Lukas Mai, Nicolas
215 R., Sawyer X, Smylers, Steve Hay, Tom Hukins, Tony Cook, Yves Orton, Zefram.
217 The list above is almost certainly incomplete as it is automatically generated
218 from version control history. In particular, it does not include the names of
219 the (very much appreciated) contributors who reported issues to the Perl bug
222 Many of the changes included in this version originated in the CPAN modules
223 included in Perl's core. We're grateful to the entire CPAN community for
224 helping Perl to flourish.
226 For a more complete list of all of Perl's historical contributors, please see
227 the F<AUTHORS> file in the Perl source distribution.
229 =head1 Reporting Bugs
231 If you find what you think is a bug, you might check the perl bug database
232 at L<https://rt.perl.org/> . There may also be information at
233 L<http://www.perl.org/> , the Perl Home Page.
235 If you believe you have an unreported bug, please run the L<perlbug> program
236 included with your release. Be sure to trim your bug down to a tiny but
237 sufficient test case. Your bug report, along with the output of C<perl -V>,
238 will be sent off to perlbug@perl.org to be analysed by the Perl porting team.
240 If the bug you are reporting has security implications which make it
241 inappropriate to send to a publicly archived mailing list, then see
242 L<perlsec/SECURITY VULNERABILITY CONTACT INFORMATION>
243 for details of how to report the issue.
247 If you wish to thank the Perl 5 Porters for the work we had done in Perl 5,
248 you can do so by running the C<perlthanks> program:
252 This will send an email to the Perl 5 Porters list with your show of thanks.
256 The F<Changes> file for an explanation of how to view exhaustive details on
259 The F<INSTALL> file for how to build Perl.
261 The F<README> file for general stuff.
263 The F<Artistic> and F<Copying> files for copyright information.