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Add warning message for locale/Unicode intermixing
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1=encoding utf8
2
3=head1 NAME
4
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5[ this is a template for a new perldelta file. Any text flagged as XXX needs
6to be processed before release. ]
7
8perldelta - what is new for perl v5.21.6
c68523cb 9
238894db 10=head1 DESCRIPTION
c68523cb 11
86372193 12This document describes differences between the 5.21.5 release and the 5.21.6
238894db 13release.
c68523cb 14
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15If you are upgrading from an earlier release such as 5.21.4, first read
16L<perl5215delta>, which describes differences between 5.21.4 and 5.21.5.
8435afd1 17
86372193 18=head1 Notice
5cfa0642 19
86372193 20XXX Any important notices here
4cad5dc8 21
86372193 22=head1 Core Enhancements
4cad5dc8 23
86372193
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24XXX New core language features go here. Summarize user-visible core language
25enhancements. Particularly prominent performance optimisations could go
26here, but most should go in the L</Performance Enhancements> section.
a5591204 27
86372193 28[ List each enhancement as a =head2 entry ]
a5591204 29
518159a1
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30=head2 List form of pipe open implemented for Win32
31
32The list form of pipe:
33
34 open my $fh, "-|", "program", @arguments;
35
36is now implemented on Win32. It has the same limitations as C<system
37LIST> on Win32, since the Win32 API doesn't accept program arguments
38as a list.
39
86372193 40=head1 Security
a5591204 41
86372193
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42XXX Any security-related notices go here. In particular, any security
43vulnerabilities closed should be noted here rather than in the
44L</Selected Bug Fixes> section.
a5591204 45
86372193 46[ List each security issue as a =head2 entry ]
a5591204 47
86372193 48=head1 Incompatible Changes
a5591204 49
86372193 50XXX For a release on a stable branch, this section aspires to be:
a5591204 51
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52 There are no changes intentionally incompatible with 5.XXX.XXX
53 If any exist, they are bugs, and we request that you submit a
54 report. See L</Reporting Bugs> below.
b15c1b56 55
86372193 56[ List each incompatible change as a =head2 entry ]
b15c1b56 57
86372193 58=head1 Deprecations
bb8c7e27 59
86372193 60XXX Any deprecated features, syntax, modules etc. should be listed here.
bb8c7e27 61
86372193 62=head2 Module removals
bb8c7e27 63
86372193 64XXX Remove this section if inapplicable.
9a88d663 65
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66The following modules will be removed from the core distribution in a
67future release, and will at that time need to be installed from CPAN.
68Distributions on CPAN which require these modules will need to list them as
69prerequisites.
9a88d663 70
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71The core versions of these modules will now issue C<"deprecated">-category
72warnings to alert you to this fact. To silence these deprecation warnings,
73install the modules in question from CPAN.
5cfa0642 74
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75Note that these are (with rare exceptions) fine modules that you are encouraged
76to continue to use. Their disinclusion from core primarily hinges on their
77necessity to bootstrapping a fully functional, CPAN-capable Perl installation,
78not usually on concerns over their design.
ba474e87 79
86372193 80=over
8435afd1 81
86372193 82=item XXX
d0ab07ee 83
86372193
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84XXX Note that deprecated modules should be listed here even if they are listed
85as an updated module in the L</Modules and Pragmata> section.
cc4d09e1 86
86372193 87=back
cc4d09e1 88
86372193 89[ List each other deprecation as a =head2 entry ]
8435afd1 90
4475d0d2
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91=head2 Use of non-graphic characters in single-character variable names
92
93The syntax for single-character variable names is more lenient than
94for longer variable names, allowing the one-character name to be a
95punctuation character or even invisible (a non-graphic). Perl v5.20
96deprecated the ASCII-range controls as such a name. Now, all
97non-graphic characters that formerly were allowed are deprecated.
98The practical effect of this occurs only when not under C<S<"use
99utf8">>, and affects just the C1 controls (code points 0x80 through
1000xFF), NO-BREAK SPACE, and SOFT HYPHEN.
101
8c8d6154 102=head1 Performance Enhancements
5cfa0642 103
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104XXX Changes which enhance performance without changing behaviour go here.
105There may well be none in a stable release.
5cfa0642 106
86372193 107[ List each enhancement as a =item entry ]
8435afd1 108
86372193 109=over 4
5cfa0642 110
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111=item *
112
86372193 113XXX
5b306eef 114
86372193 115=back
357205d5 116
86372193 117=head1 Modules and Pragmata
357205d5 118
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119XXX All changes to installed files in F<cpan/>, F<dist/>, F<ext/> and F<lib/>
120go here. If Module::CoreList is updated, generate an initial draft of the
121following sections using F<Porting/corelist-perldelta.pl>. A paragraph summary
122for important changes should then be added by hand. In an ideal world,
123dual-life modules would have a F<Changes> file that could be cribbed.
f704f251 124
86372193 125[ Within each section, list entries as a =item entry ]
f704f251 126
86372193 127=head2 New Modules and Pragmata
0cb3abac 128
86372193 129=over 4
0cb3abac 130
deec1830
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131=item *
132
86372193 133XXX
deec1830 134
8c8d6154 135=back
d0ab07ee 136
8c8d6154 137=head2 Updated Modules and Pragmata
d99849ae 138
39c4a6cf 139=over 4
d99849ae 140
ff433f2d
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141=item *
142
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143L<IO::Socket> has been upgraded from version 1.37 to 1.38.
144
145Document the limitations of the isconnected() method. [perl #123096]
cbfcbc14 146
86372193 147=back
f348c3d8 148
86372193 149=head2 Removed Modules and Pragmata
f348c3d8 150
86372193 151=over 4
f348c3d8
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152
153=item *
154
86372193 155XXX
f348c3d8 156
86372193 157=back
7635ad4d 158
86372193 159=head1 Documentation
7635ad4d 160
86372193
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161XXX Changes to files in F<pod/> go here. Consider grouping entries by
162file and be sure to link to the appropriate page, e.g. L<perlfunc>.
7635ad4d 163
86372193 164=head2 New Documentation
f348c3d8 165
86372193 166XXX Changes which create B<new> files in F<pod/> go here.
f348c3d8 167
86372193 168=head3 L<XXX>
f4eedc6b 169
86372193 170XXX Description of the purpose of the new file here
f4eedc6b 171
86372193 172=head2 Changes to Existing Documentation
f4eedc6b 173
86372193
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174XXX Changes which significantly change existing files in F<pod/> go here.
175However, any changes to F<pod/perldiag.pod> should go in the L</Diagnostics>
176section.
f348c3d8 177
42327f06 178=head3 L<perldata/Identifier parsing>
f348c3d8 179
86372193 180=over 4
f348c3d8
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181
182=item *
183
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184The syntax of single-character variable names has been brought
185up-to-date and more fully explained.
f348c3d8 186
86372193 187=back
f348c3d8 188
86372193 189=head1 Diagnostics
f348c3d8 190
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191The following additions or changes have been made to diagnostic output,
192including warnings and fatal error messages. For the complete list of
193diagnostic messages, see L<perldiag>.
f348c3d8 194
86372193
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195XXX New or changed warnings emitted by the core's C<C> code go here. Also
196include any changes in L<perldiag> that reconcile it to the C<C> code.
f348c3d8 197
86372193 198=head2 New Diagnostics
f348c3d8 199
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200XXX Newly added diagnostic messages go under here, separated into New Errors
201and New Warnings
f348c3d8 202
86372193 203=head3 New Errors
84d03adf 204
86372193 205=over 4
ff433f2d 206
4cd408ba
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207=item *
208
86372193 209XXX L<message|perldiag/"message">
f348c3d8 210
86372193 211=back
f348c3d8 212
86372193 213=head3 New Warnings
f4eedc6b 214
86372193 215=over 4
f4eedc6b
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216
217=item *
218
4475d0d2 219L<Use of literal non-graphic characters in variable names is deprecated|perldiag/"Use of literal non-graphic characters in variable names is deprecated">
f348c3d8 220
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221=item *
222
223L<Can't do %s("%s") on non-UTF-8 locale; resolved to "%s".|perldiag/Can't do %s("%s") on non-UTF-8 locale; resolved to "%s".>
224
86372193 225=back
0561e60b 226
86372193 227=head2 Changes to Existing Diagnostics
0561e60b 228
86372193 229XXX Changes (i.e. rewording) of diagnostic messages go here
0561e60b 230
86372193 231=over 4
4cd408ba 232
f348c3d8
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233=item *
234
86372193 235XXX Describe change here
4cd408ba 236
86372193 237=back
40a81b59 238
86372193 239=head1 Utility Changes
f348c3d8 240
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241XXX Changes to installed programs such as F<perlbug> and F<xsubpp> go here.
242Most of these are built within the directory F<utils>.
f348c3d8 243
86372193
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244[ List utility changes as a =head2 entry for each utility and =item
245entries for each change
246Use L<XXX> with program names to get proper documentation linking. ]
f348c3d8 247
86372193 248=head2 L<XXX>
f348c3d8 249
86372193 250=over 4
f348c3d8
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251
252=item *
253
86372193 254XXX
40a81b59 255
13900f93 256=back
aac7f82f 257
86372193 258=head1 Configuration and Compilation
2a395b86 259
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260XXX Changes to F<Configure>, F<installperl>, F<installman>, and analogous tools
261go here. Any other changes to the Perl build process should be listed here.
262However, any platform-specific changes should be listed in the
263L</Platform Support> section, instead.
8435afd1 264
86372193 265[ List changes as a =item entry ].
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266
267=over 4
2a395b86 268
12d22d1f
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269=item *
270
c517e197 271F<Configure> with C<-Dmksymlinks> should now be faster. [perl #122002]
12d22d1f 272
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273=back
274
86372193 275=head1 Testing
2a395b86 276
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277XXX Any significant changes to the testing of a freshly built perl should be
278listed here. Changes which create B<new> files in F<t/> go here as do any
279large changes to the testing harness (e.g. when parallel testing was added).
280Changes to existing files in F<t/> aren't worth summarizing, although the bugs
281that they represent may be covered elsewhere.
2a395b86 282
86372193 283[ List each test improvement as a =item entry ]
5cfa0642 284
8c8d6154 285=over 4
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286
287=item *
288
86372193 289XXX
bb8c7e27 290
86372193 291=back
bb8c7e27 292
86372193 293=head1 Platform Support
bb8c7e27 294
86372193 295XXX Any changes to platform support should be listed in the sections below.
bb8c7e27 296
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297[ Within the sections, list each platform as a =item entry with specific
298changes as paragraphs below it. ]
2a395b86 299
86372193 300=head2 New Platforms
6d9b7c7c 301
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302XXX List any platforms that this version of perl compiles on, that previous
303versions did not. These will either be enabled by new files in the F<hints/>
304directories, or new subdirectories and F<README> files at the top level of the
305source tree.
363d3025 306
8c8d6154 307=over 4
334464b3 308
86372193 309=item XXX-some-platform
334464b3 310
86372193 311XXX
ef5a9509 312
363d3025
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313=back
314
86372193
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315=head2 Discontinued Platforms
316
317XXX List any platforms that this version of perl no longer compiles on.
d72cd2eb 318
0346c3a9 319=over 4
375f5f06 320
86372193 321=item XXX-some-platform
2884baee 322
86372193 323XXX
6f1a844b 324
8c8d6154 325=back
549ea8d4 326
8c8d6154 327=head2 Platform-Specific Notes
aa292ef2 328
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329XXX List any changes for specific platforms. This could include configuration
330and compilation changes or changes in portability/compatibility. However,
331changes within modules for platforms should generally be listed in the
332L</Modules and Pragmata> section.
333
8c8d6154 334=over 4
739e9bee 335
86372193 336=item XXX-some-platform
739e9bee 337
86372193 338XXX
b23b2fdb 339
8c8d6154 340=back
b23b2fdb 341
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342=head3 Win32
343
344=over 4
345
346=item *
347
348In the experimental C<:win32> layer, a crash in C<open> was fixed. Also
349opening C</dev/null>, which works the Win32 Perl's normal C<:unix> layer, was
350implemented for C<:win32>.
351L<[perl #122224]|https://rt.perl.org/Ticket/Display.html?id=122224>
352
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353=item *
354
355A new makefile option, C<USE_LONG_DOUBLE>, has been added to the Windows
356dmake makefile for gcc builds only. Set this to "define" if you want perl to
357use long doubles to give more accuracy and range for floating point numbers.
358
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359=back
360
8c8d6154 361=head1 Internal Changes
7d15b1a8 362
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363XXX Changes which affect the interface available to C<XS> code go here. Other
364significant internal changes for future core maintainers should be noted as
365well.
bbca64cf 366
86372193 367[ List each change as a =item entry ]
6ff8f256 368
86372193 369=over 4
28482d6c 370
28a42920
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371=item *
372
86372193 373XXX
28a42920 374
8c8d6154 375=back
6ff8f256 376
8c8d6154 377=head1 Selected Bug Fixes
80cc3290 378
86372193
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379XXX Important bug fixes in the core language are summarized here. Bug fixes in
380files in F<ext/> and F<lib/> are best summarized in L</Modules and Pragmata>.
13dd5671 381
86372193 382[ List each fix as a =item entry ]
bdab7676 383
86372193 384=over 4
db98db4e 385
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386=item *
387
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388fchmod() and futimes() now set C<$!> when they fail due to being
389passed a closed file handle. [perl #122703]
bb8c7e27 390
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391=item *
392
393Perl now comes with a corrected Unicode 7.0 for the erratum issued on
394October 21, 2014 (see L<http://www.unicode.org/errata/#current_errata>),
395dealing with glyph shaping in Arabic.
396
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397=item *
398
399op_free() no longer crashes due to a stack overflow when freeing a
400deeply recursive op tree. [perl #108276]
401
53795ef8
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402=item *
403
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404scalarvoid() would crash due to a stack overflow when processing a
405deeply recursive op tree. [perl #108276]
406
407=item *
408
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409In Perl 5.20.0, C<$^N> accidentally had the internal UTF8 flag turned off
410if accessed from a code block within a regular expression, effectively
411UTF8-encoding the value. This has been fixed. [perl #123135]
412
86372193 413=back
bb8c7e27 414
86372193 415=head1 Known Problems
bb8c7e27 416
86372193
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417XXX Descriptions of platform agnostic bugs we know we can't fix go here. Any
418tests that had to be C<TODO>ed for the release would be noted here. Unfixed
419platform specific bugs also go here.
bb8c7e27 420
86372193 421[ List each fix as a =item entry ]
bb8c7e27 422
86372193 423=over 4
bb8c7e27 424
74f9f9ed
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425=item *
426
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427Starting in 5.21.6, accessing L<perlapi/CvPADLIST> in an XSUB is forbidden.
428CvPADLIST has be reused for a different internal purpose for XSUBs. Guard all
429CvPADLIST expressions with C<CvISXSUB()> if your code doesn't already block
430XSUB CV*s from going through optree CV* expecting code.
28a42920 431
86372193 432=back
28a42920 433
86372193 434=head1 Errata From Previous Releases
28a42920 435
86372193 436=over 4
28a42920
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437
438=item *
439
86372193
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440XXX Add anything here that we forgot to add, or were mistaken about, in
441the perldelta of a previous release.
28a42920 442
8c8d6154 443=back
3a085d00 444
86372193 445=head1 Obituary
01d42a22 446
86372193
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447XXX If any significant core contributor has died, we've added a short obituary
448here.
01d42a22 449
86372193 450=head1 Acknowledgements
01d42a22 451
86372193 452XXX Generate this with:
01d42a22 453
86372193 454 perl Porting/acknowledgements.pl v5.21.5..HEAD
f5b73711 455
44691e6f
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456=head1 Reporting Bugs
457
e08634c5
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458If you find what you think is a bug, you might check the articles recently
459posted to the comp.lang.perl.misc newsgroup and the perl bug database at
238894db 460https://rt.perl.org/ . There may also be information at
7ef8b31d 461http://www.perl.org/ , the Perl Home Page.
44691e6f 462
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463If you believe you have an unreported bug, please run the L<perlbug> program
464included with your release. Be sure to trim your bug down to a tiny but
465sufficient test case. Your bug report, along with the output of C<perl -V>,
466will be sent off to perlbug@perl.org to be analysed by the Perl porting team.
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467
468If the bug you are reporting has security implications, which make it
e08634c5
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469inappropriate to send to a publicly archived mailing list, then please send it
470to perl5-security-report@perl.org. This points to a closed subscription
471unarchived mailing list, which includes all the core committers, who will be
472able to help assess the impact of issues, figure out a resolution, and help
f9001595 473co-ordinate the release of patches to mitigate or fix the problem across all
e08634c5
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474platforms on which Perl is supported. Please only use this address for
475security issues in the Perl core, not for modules independently distributed on
476CPAN.
44691e6f
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477
478=head1 SEE ALSO
479
e08634c5
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480The F<Changes> file for an explanation of how to view exhaustive details on
481what changed.
44691e6f
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482
483The F<INSTALL> file for how to build Perl.
484
485The F<README> file for general stuff.
486
487The F<Artistic> and F<Copying> files for copyright information.
488
489=cut