1PERL5202DELTA(1)       Perl Programmers Reference Guide       PERL5202DELTA(1)
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NAME

6       perl5202delta - what is new for perl v5.20.2
7

DESCRIPTION

9       This document describes differences between the 5.20.1 release and the
10       5.20.2 release.
11
12       If you are upgrading from an earlier release such as 5.20.0, first read
13       perl5201delta, which describes differences between 5.20.0 and 5.20.1.
14

Incompatible Changes

16       There are no changes intentionally incompatible with 5.20.1.  If any
17       exist, they are bugs, and we request that you submit a report.  See
18       "Reporting Bugs" below.
19

Modules and Pragmata

21   Updated Modules and Pragmata
22       •   attributes has been upgraded from version 0.22 to 0.23.
23
24           The usage of "memEQs" in the XS has been corrected.  [perl #122701]
25           <https://rt.perl.org/Ticket/Display.html?id=122701>
26
27       •   Data::Dumper has been upgraded from version 2.151 to 2.151_01.
28
29           Fixes CVE-2014-4330 by adding a configuration variable/option to
30           limit recursion when dumping deep data structures.
31
32       •   Errno has been upgraded from version 1.20_03 to 1.20_05.
33
34           Warnings when building the XS on Windows with the Visual C++
35           compiler are now avoided.
36
37       •   feature has been upgraded from version 1.36 to 1.36_01.
38
39           The "postderef" feature has now been documented.  This feature was
40           actually added in Perl 5.20.0 but was accidentally omitted from the
41           feature documentation until now.
42
43       •   IO::Socket has been upgraded from version 1.37 to 1.38.
44
45           Document the limitations of the connected() method.  [perl #123096]
46           <https://rt.perl.org/Ticket/Display.html?id=123096>
47
48       •   Module::CoreList has been upgraded from version 5.020001 to
49           5.20150214.
50
51           The list of Perl versions covered has been updated.
52
53       •   PathTools has been upgraded from version 3.48 to 3.48_01.
54
55           A warning from the gcc compiler is now avoided when building the
56           XS.
57
58       •   PerlIO::scalar has been upgraded from version 0.18 to 0.18_01.
59
60           Reading from a position well past the end of the scalar now
61           correctly returns end of file.  [perl #123443]
62           <https://rt.perl.org/Ticket/Display.html?id=123443>
63
64           Seeking to a negative position still fails, but no longer leaves
65           the file position set to a negation location.
66
67           "eof()" on a "PerlIO::scalar" handle now properly returns true when
68           the file position is past the 2GB mark on 32-bit systems.
69
70       •   Storable has been upgraded from version 2.49 to 2.49_01.
71
72           Minor grammatical change to the documentation only.
73
74       •   VMS::DCLsym has been upgraded from version 1.05 to 1.05_01.
75
76           Minor formatting change to the documentation only.
77
78       •   VMS::Stdio has been upgraded from version 2.4 to 2.41.
79
80           Minor formatting change to the documentation only.
81

Documentation

83   New Documentation
84       perlunicook
85
86       This document, by Tom Christiansen, provides examples of handling
87       Unicode in Perl.
88
89   Changes to Existing Documentation
90       perlexperiment
91
92       •   Added reference to subroutine signatures.  This feature was
93           actually added in Perl 5.20.0 but was accidentally omitted from the
94           experimental feature documentation until now.
95
96       perlpolicy
97
98       •   The process whereby features may graduate from experimental status
99           has now been formally documented.
100
101       perlsyn
102
103       •   An ambiguity in the documentation of the ellipsis statement has
104           been corrected.  [perl #122661]
105           <https://rt.perl.org/Ticket/Display.html?id=122661>
106

Diagnostics

108       The following additions or changes have been made to diagnostic output,
109       including warnings and fatal error messages.  For the complete list of
110       diagnostic messages, see perldiag.
111
112   Changes to Existing Diagnostics
113       •   Bad symbol for scalar is now documented.  This error is not new,
114           but was not previously documented here.
115
116       •   Missing right brace on \N{} is now documented.  This error is not
117           new, but was not previously documented here.
118

Testing

120       •   The test script re/rt122747.t has been added to verify that perl
121           #122747 <https://rt.perl.org/Ticket/Display.html?id=122747> remains
122           fixed.
123

Platform Support

125   Regained Platforms
126       IRIX and Tru64 platforms are working again.  (Some "make test" failures
127       remain.)
128

Selected Bug Fixes

130       •   AIX now sets the length in "getsockopt" correctly.  [perl #120835]
131           <https://rt.perl.org/Ticket/Display.html?id=120835>, [cpan #91183]
132           <https://rt.cpan.org/Ticket/Display.html?id=91183>, [cpan #85570]
133           <https://rt.cpan.org/Ticket/Display.html?id=85570>
134
135       •   In Perl 5.20.0, $^N accidentally had the internal UTF8 flag turned
136           off if accessed from a code block within a regular expression,
137           effectively UTF8-encoding the value.  This has been fixed.  [perl
138           #123135] <https://rt.perl.org/Ticket/Display.html?id=123135>
139
140       •   Various cases where the name of a sub is used (autoload,
141           overloading, error messages) used to crash for lexical subs, but
142           have been fixed.
143
144       •   An assertion failure when parsing "sort" with debugging enabled has
145           been fixed.  [perl #122771]
146           <https://rt.perl.org/Ticket/Display.html?id=122771>
147
148       •   Loading UTF8 tables during a regular expression match could cause
149           assertion failures under debugging builds if the previous match
150           used the very same regular expression.  [perl #122747]
151           <https://rt.perl.org/Ticket/Display.html?id=122747>
152
153       •   Due to a mistake in the string-copying logic, copying the value of
154           a state variable could instead steal the value and undefine the
155           variable.  This bug, introduced in Perl 5.20, would happen mostly
156           for long strings (1250 chars or more), but could happen for any
157           strings under builds with copy-on-write disabled.  [perl #123029]
158           <https://rt.perl.org/Ticket/Display.html?id=123029>
159
160       •   Fixed a bug that could cause perl to execute an infinite loop
161           during compilation.  [perl #122995]
162           <https://rt.perl.org/Ticket/Display.html?id=122995>
163
164       •   On Win32, restoring in a child pseudo-process a variable that was
165           "local()"ed in a parent pseudo-process before the "fork" happened
166           caused memory corruption and a crash in the child pseudo-process
167           (and therefore OS process).  [perl #40565]
168           <https://rt.perl.org/Ticket/Display.html?id=40565>
169
170       •   Tainted constants evaluated at compile time no longer cause
171           unrelated statements to become tainted.  [perl #122669]
172           <https://rt.perl.org/Ticket/Display.html?id=122669>
173
174       •   Calling "write" on a format with a "^**" field could produce a
175           panic in sv_chop() if there were insufficient arguments or if the
176           variable used to fill the field was empty.  [perl #123245]
177           <https://rt.perl.org/Ticket/Display.html?id=123245>
178
179       •   In Perl 5.20.0, "sort CORE::fake" where 'fake' is anything other
180           than a keyword started chopping of the last 6 characters and
181           treating the result as a sort sub name.  The previous behaviour of
182           treating "CORE::fake" as a sort sub name has been restored.  [perl
183           #123410] <https://rt.perl.org/Ticket/Display.html?id=123410>
184
185       •   A bug in regular expression patterns that could lead to segfaults
186           and other crashes has been fixed.  This occurred only in patterns
187           compiled with "/i", while taking into account the current POSIX
188           locale (this usually means they have to be compiled within the
189           scope of "use locale"), and there must be a string of at least 128
190           consecutive bytes to match.  [perl #123539]
191           <https://rt.perl.org/Ticket/Display.html?id=123539>
192
193       •   "qr/@array(?{block})/" no longer dies with "Bizarre copy of ARRAY".
194           [perl #123344] <https://rt.perl.org/Ticket/Display.html?id=123344>
195
196       •   "gmtime" no longer crashes with not-a-number values.  [perl
197           #123495] <https://rt.perl.org/Ticket/Display.html?id=123495>
198
199       •   Certain syntax errors in substitutions, such as "s/${<>{})//",
200           would crash, and had done so since Perl 5.10.  (In some cases the
201           crash did not start happening until Perl 5.16.)  The crash has, of
202           course, been fixed.  [perl #123542]
203           <https://rt.perl.org/Ticket/Display.html?id=123542>
204
205       •   A memory leak in some regular expressions, introduced in Perl
206           5.20.1, has been fixed.  [perl #123198]
207           <https://rt.perl.org/Ticket/Display.html?id=123198>
208
209       •   "formline("@...", "a");" would crash.  The "FF_CHECKNL" case in
210           pp_formline() didn't set the pointer used to mark the chop
211           position, which led to the "FF_MORE" case crashing with a
212           segmentation fault.  This has been fixed.  [perl #123538]
213           <https://rt.perl.org/Ticket/Display.html?id=123538> [perl #123622]
214           <https://rt.perl.org/Ticket/Display.html?id=123622>
215
216       •   A possible buffer overrun and crash when parsing a literal pattern
217           during regular expression compilation has been fixed.  [perl
218           #123604] <https://rt.perl.org/Ticket/Display.html?id=123604>
219

Known Problems

221       •   It is a known bug that lexical subroutines cannot be used as the
222           "SUBNAME" argument to "sort".  This will be fixed in a future
223           version of Perl.
224

Errata From Previous Releases

226       •   A regression has been fixed that was introduced in Perl 5.20.0
227           (fixed in Perl 5.20.1 as well as here) in which a UTF-8 encoded
228           regular expression pattern that contains a single ASCII lowercase
229           letter does not match its uppercase counterpart.  [perl #122655]
230           <https://rt.perl.org/Ticket/Display.html?id=122655>
231

Acknowledgements

233       Perl 5.20.2 represents approximately 5 months of development since Perl
234       5.20.1 and contains approximately 6,300 lines of changes across 170
235       files from 34 authors.
236
237       Excluding auto-generated files, documentation and release tools, there
238       were approximately 1,900 lines of changes to 80 .pm, .t, .c and .h
239       files.
240
241       Perl continues to flourish into its third decade thanks to a vibrant
242       community of users and developers.  The following people are known to
243       have contributed the improvements that became Perl 5.20.2:
244
245       Aaron Crane, Abigail, Andreas Voegele, Andy Dougherty, Anthony Heading,
246       Aristotle Pagaltzis, Chris 'BinGOs' Williams, Craig A. Berry, Daniel
247       Dragan, Doug Bell, Ed J, Father Chrysostomos, Glenn D. Golden, H.Merijn
248       Brand, Hugo van der Sanden, James E Keenan, Jarkko Hietaniemi, Jim
249       Cromie, Karen Etheridge, Karl Williamson, kmx, Matthew Horsfall, Max
250       Maischein, Peter Martini, Rafael Garcia-Suarez, Ricardo Signes, Shlomi
251       Fish, Slaven Rezic, Steffen Mueller, Steve Hay, Tadeusz SoXnierz, Tony
252       Cook, Yves Orton, AEvar Arnfjoerd` Bjarmason.
253
254       The list above is almost certainly incomplete as it is automatically
255       generated from version control history.  In particular, it does not
256       include the names of the (very much appreciated) contributors who
257       reported issues to the Perl bug tracker.
258
259       Many of the changes included in this version originated in the CPAN
260       modules included in Perl's core.  We're grateful to the entire CPAN
261       community for helping Perl to flourish.
262
263       For a more complete list of all of Perl's historical contributors,
264       please see the AUTHORS file in the Perl source distribution.
265

Reporting Bugs

267       If you find what you think is a bug, you might check the articles
268       recently posted to the comp.lang.perl.misc newsgroup and the perl bug
269       database at https://rt.perl.org/ .  There may also be information at
270       http://www.perl.org/ , the Perl Home Page.
271
272       If you believe you have an unreported bug, please run the perlbug
273       program included with your release.  Be sure to trim your bug down to a
274       tiny but sufficient test case.  Your bug report, along with the output
275       of "perl -V", will be sent off to perlbug@perl.org to be analysed by
276       the Perl porting team.
277
278       If the bug you are reporting has security implications, which make it
279       inappropriate to send to a publicly archived mailing list, then please
280       send it to perl5-security-report@perl.org.  This points to a closed
281       subscription unarchived mailing list, which includes all the core
282       committers, who will be able to help assess the impact of issues,
283       figure out a resolution, and help co-ordinate the release of patches to
284       mitigate or fix the problem across all platforms on which Perl is
285       supported.  Please only use this address for security issues in the
286       Perl core, not for modules independently distributed on CPAN.
287

SEE ALSO

289       The Changes file for an explanation of how to view exhaustive details
290       on what changed.
291
292       The INSTALL file for how to build Perl.
293
294       The README file for general stuff.
295
296       The Artistic and Copying files for copyright information.
297
298
299
300perl v5.32.1                      2021-05-31                  PERL5202DELTA(1)
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