perl5201delta(1)

1PERL5201DELTA(1)       Perl Programmers Reference Guide       PERL5201DELTA(1)
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NAME

6       perl5201delta - what is new for perl v5.20.1
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DESCRIPTION

9       This document describes differences between the 5.20.0 release and the
10       5.20.1 release.
11
12       If you are upgrading from an earlier release such as 5.18.0, first read
13       perl5200delta, which describes differences between 5.18.0 and 5.20.0.
14

Incompatible Changes

16       There are no changes intentionally incompatible with 5.20.0.  If any
17       exist, they are bugs, and we request that you submit a report.  See
18       "Reporting Bugs" below.
19

Performance Enhancements

21       •   An optimization to avoid problems with COW and deliberately
22           overallocated PVs has been disabled because it interfered with
23           another, more important, optimization, causing a slowdown on some
24           platforms.  [GH #13878]
25           <https://github.com/Perl/perl5/issues/13878>
26
27       •   Returning a string from a lexical variable could be slow in some
28           cases.  This has now been fixed.  [GH #13880]
29           <https://github.com/Perl/perl5/issues/13880>
30

Modules and Pragmata

32   Updated Modules and Pragmata
33       •   Config::Perl::V has been upgraded from version 0.20 to 0.22.
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35           The list of Perl versions covered has been updated and some flaws
36           in the parsing have been fixed.
37
38       •   Exporter has been upgraded from version 5.70 to 5.71.
39
40           Illegal POD syntax in the documentation has been corrected.
41
42       •   ExtUtils::CBuilder has been upgraded from version 0.280216 to
43           0.280217.
44
45           Android builds now link to both -lperl and
46           $Config::Config{perllibs}.
47
48       •   File::Copy has been upgraded from version 2.29 to 2.30.
49
50           The documentation now notes that "copy" will not overwrite read-
51           only files.
52
53       •   Module::CoreList has been upgraded from version 3.11 to 5.020001.
54
55           The list of Perl versions covered has been updated.
56
57       •   The PathTools module collection has been upgraded from version 3.47
58           to 3.48.
59
60           Fallbacks are now in place when cross-compiling for Android and
61           $Config::Config{sh} is not yet defined.  [GH #13872]
62           <https://github.com/Perl/perl5/issues/13872>
63
64       •   PerlIO::via has been upgraded from version 0.14 to 0.15.
65
66           A minor portability improvement has been made to the XS
67           implementation.
68
69       •   Unicode::UCD has been upgraded from version 0.57 to 0.58.
70
71           The documentation includes many clarifications and fixes.
72
73       •   utf8 has been upgraded from version 1.13 to 1.13_01.
74
75           The documentation has some minor formatting improvements.
76
77       •   version has been upgraded from version 0.9908 to 0.9909.
78
79           External libraries and Perl may have different ideas of what the
80           locale is.  This is problematic when parsing version strings if the
81           locale's numeric separator has been changed.  Version parsing has
82           been patched to ensure it handles the locales correctly.  [GH
83           #13863] <https://github.com/Perl/perl5/issues/13863>
84

Documentation

86   Changes to Existing Documentation
87       perlapi
88
89       •   "av_len" - Emphasize that this returns the highest index in the
90           array, not the size of the array.  [GH #13377]
91           <https://github.com/Perl/perl5/issues/13377>
92
93       •   Note that "SvSetSV" doesn't do set magic.
94
95       •   "sv_usepvn_flags" - Fix documentation to mention the use of "NewX"
96           instead of "malloc".  [GH #13835]
97           <https://github.com/Perl/perl5/issues/13835>
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99       •   Clarify where "NUL" may be embedded or is required to terminate a
100           string.
101
102       perlfunc
103
104       •   Clarify the meaning of "-B" and "-T".
105
106       •   "-l" now notes that it will return false if symlinks aren't
107           supported by the file system.  [GH #13695]
108           <https://github.com/Perl/perl5/issues/13695>
109
110       •   Note that "each", "keys" and "values" may produce different
111           orderings for tied hashes compared to other perl hashes.  [GH
112           #13650] <https://github.com/Perl/perl5/issues/13650>
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114       •   Note that "exec LIST" and "system LIST" may fall back to the shell
115           on Win32.  Only "exec PROGRAM LIST" and "system PROGRAM LIST"
116           indirect object syntax will reliably avoid using the shell.  This
117           has also been noted in perlport.  [GH #13907]
118           <https://github.com/Perl/perl5/issues/13907>
119
120       •   Clarify the meaning of "our".  [GH #13938]
121           <https://github.com/Perl/perl5/issues/13938>
122
123       perlguts
124
125       •   Explain various ways of modifying an existing SV's buffer.  [GH
126           #12813] <https://github.com/Perl/perl5/issues/12813>
127
128       perlpolicy
129
130       •   We now have a code of conduct for the p5p mailing list, as
131           documented in "STANDARDS OF CONDUCT" in perlpolicy.
132
133       perlre
134
135       •   The "/x" modifier has been clarified to note that comments cannot
136           be continued onto the next line by escaping them.
137
138       perlsyn
139
140       •   Mention the use of empty conditionals in "for"/"while" loops for
141           infinite loops.
142
143       perlxs
144
145       •   Added a discussion of locale issues in XS code.
146

Diagnostics

148       The following additions or changes have been made to diagnostic output,
149       including warnings and fatal error messages.  For the complete list of
150       diagnostic messages, see perldiag.
151
152   Changes to Existing Diagnostics
153       •   Variable length lookbehind not implemented in regex m/%s/
154
155           Information about Unicode behaviour has been added.
156

Configuration and Compilation

158       •   Building Perl no longer writes to the source tree when configured
159           with Configure's -Dmksymlinks option.  [GH #13712]
160           <https://github.com/Perl/perl5/issues/13712>
161

Platform Support

163   Platform-Specific Notes
164       Android
165           Build support has been improved for cross-compiling in general and
166           for Android in particular.
167
168       OpenBSD
169           Corrected architectures and version numbers used in configuration
170           hints when building Perl.
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172       Solaris
173           c99 options have been cleaned up, hints look for solstudio as well
174           as SUNWspro, and support for native "setenv" has been added.
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176       VMS An old bug in feature checking, mainly affecting pre-7.3 systems,
177           has been fixed.
178
179       Windows
180           %I64d is now being used instead of %lld for MinGW.
181

Internal Changes

183       •   Added "sync_locale" in perlapi.  Changing the program's locale
184           should be avoided by XS code.  Nevertheless, certain non-Perl
185           libraries called from XS, such as "Gtk" do so.  When this happens,
186           Perl needs to be told that the locale has changed.  Use this
187           function to do so, before returning to Perl.
188

Selected Bug Fixes

190       •   A bug has been fixed where zero-length assertions and code blocks
191           inside of a regex could cause "pos" to see an incorrect value.  [GH
192           #14016] <https://github.com/Perl/perl5/issues/14016>
193
194       •   Using "s///e" on tainted utf8 strings could issue bogus "Malformed
195           UTF-8 character (unexpected end of string)" warnings.  This has now
196           been fixed.  [GH #13948]
197           <https://github.com/Perl/perl5/issues/13948>
198
199       •   "system" and friends should now work properly on more Android
200           builds.
201
202           Due to an oversight, the value specified through -Dtargetsh to
203           Configure would end up being ignored by some of the build process.
204           This caused perls cross-compiled for Android to end up with
205           defective versions of "system", "exec" and backticks: the commands
206           would end up looking for /bin/sh instead of /system/bin/sh, and so
207           would fail for the vast majority of devices, leaving $! as
208           "ENOENT".
209
210       •   Many issues have been detected by Coverity
211           <http://www.coverity.com/> and fixed.
212

Acknowledgements

214       Perl 5.20.1 represents approximately 4 months of development since Perl
215       5.20.0 and contains approximately 12,000 lines of changes across 170
216       files from 36 authors.
217
218       Excluding auto-generated files, documentation and release tools, there
219       were approximately 2,600 lines of changes to 110 .pm, .t, .c and .h
220       files.
221
222       Perl continues to flourish into its third decade thanks to a vibrant
223       community of users and developers.  The following people are known to
224       have contributed the improvements that became Perl 5.20.1:
225
226       Aaron Crane, Abigail, Alberto Simões, Alexandr Ciornii, Alexandre
227       (Midnite) Jousset, Andrew Fresh, Andy Dougherty, Brian Fraser, Chris
228       'BinGOs' Williams, Craig A. Berry, Daniel Dragan, David Golden, David
229       Mitchell, H.Merijn Brand, James E Keenan, Jan Dubois, Jarkko
230       Hietaniemi, John Peacock, kafka, Karen Etheridge, Karl Williamson,
231       Lukas Mai, Matthew Horsfall, Michael Bunk, Peter Martini, Rafael
232       Garcia-Suarez, Reini Urban, Ricardo Signes, Shirakata Kentaro, Smylers,
233       Steve Hay, Thomas Sibley, Todd Rinaldo, Tony Cook, Vladimir Marek, Yves
234       Orton.
235
236       The list above is almost certainly incomplete as it is automatically
237       generated from version control history.  In particular, it does not
238       include the names of the (very much appreciated) contributors who
239       reported issues to the Perl bug tracker.
240
241       Many of the changes included in this version originated in the CPAN
242       modules included in Perl's core.  We're grateful to the entire CPAN
243       community for helping Perl to flourish.
244
245       For a more complete list of all of Perl's historical contributors,
246       please see the AUTHORS file in the Perl source distribution.
247

Reporting Bugs

249       If you find what you think is a bug, you might check the articles
250       recently posted to the comp.lang.perl.misc newsgroup and the perl bug
251       database at https://rt.perl.org/ .  There may also be information at
252       http://www.perl.org/ , the Perl Home Page.
253
254       If you believe you have an unreported bug, please run the perlbug
255       program included with your release.  Be sure to trim your bug down to a
256       tiny but sufficient test case.  Your bug report, along with the output
257       of "perl -V", will be sent off to perlbug@perl.org to be analysed by
258       the Perl porting team.
259
260       If the bug you are reporting has security implications, which make it
261       inappropriate to send to a publicly archived mailing list, then please
262       send it to perl5-security-report@perl.org.  This points to a closed
263       subscription unarchived mailing list, which includes all the core
264       committers, who will be able to help assess the impact of issues,
265       figure out a resolution, and help co-ordinate the release of patches to
266       mitigate or fix the problem across all platforms on which Perl is
267       supported.  Please only use this address for security issues in the
268       Perl core, not for modules independently distributed on CPAN.
269