| 1 | =encoding utf8 |
| 2 | |
| 3 | =head1 NAME |
| 4 | |
| 5 | [ this is a template for a new perldelta file. Any text flagged as XXX needs |
| 6 | to be processed before release. ] |
| 7 | |
| 8 | perldelta - what is new for perl v5.21.1 |
| 9 | |
| 10 | =head1 DESCRIPTION |
| 11 | |
| 12 | This document describes differences between the 5.21.0 release and the 5.21.1 |
| 13 | release. |
| 14 | |
| 15 | If you are upgrading from an earlier release such as 5.20.0, first read |
| 16 | L<perl5210delta>, which describes differences between 5.20.0 and 5.21.0. |
| 17 | |
| 18 | =head1 Notice |
| 19 | |
| 20 | XXX Any important notices here |
| 21 | |
| 22 | =head1 Core Enhancements |
| 23 | |
| 24 | XXX New core language features go here. Summarize user-visible core language |
| 25 | enhancements. Particularly prominent performance optimisations could go |
| 26 | here, but most should go in the L</Performance Enhancements> section. |
| 27 | |
| 28 | [ List each enhancement as a =head2 entry ] |
| 29 | |
| 30 | =head2 C<qr/foo/x> now ignores any Unicode pattern white space |
| 31 | |
| 32 | The C</x> regular expression modifier allows the pattern to contain |
| 33 | white space and comments, both of which are ignored, for improved |
| 34 | readability. Until now, not all the white space characters that Unicode |
| 35 | designates for this purpose were handled. The additional ones now |
| 36 | recognized are |
| 37 | U+0085 NEXT LINE, |
| 38 | U+200E LEFT-TO-RIGHT MARK, |
| 39 | U+200F RIGHT-TO-LEFT MARK, |
| 40 | U+2028 LINE SEPARATOR, |
| 41 | and |
| 42 | U+2029 PARAGRAPH SEPARATOR. |
| 43 | |
| 44 | =head1 Security |
| 45 | |
| 46 | XXX Any security-related notices go here. In particular, any security |
| 47 | vulnerabilities closed should be noted here rather than in the |
| 48 | L</Selected Bug Fixes> section. |
| 49 | |
| 50 | [ List each security issue as a =head2 entry ] |
| 51 | |
| 52 | =head1 Incompatible Changes |
| 53 | |
| 54 | XXX For a release on a stable branch, this section aspires to be: |
| 55 | |
| 56 | There are no changes intentionally incompatible with 5.XXX.XXX |
| 57 | If any exist, they are bugs, and we request that you submit a |
| 58 | report. See L</Reporting Bugs> below. |
| 59 | |
| 60 | =head2 In double-quotish C<\cI<X>>, I<X> must now be a printable ASCII character |
| 61 | |
| 62 | In prior releases, failure to do this raised a deprecation warning. |
| 63 | |
| 64 | =head2 Splitting the tokens C<(?> and C<(*> in regular expressions is |
| 65 | now a fatal compilation error. |
| 66 | |
| 67 | These had been deprecated since v5.18. |
| 68 | |
| 69 | =head2 5 additional characters are treated as white space under C</x> in |
| 70 | regex patterns (unless escaped) |
| 71 | |
| 72 | The use of these characters with C</x> outside bracketed character |
| 73 | classes and when not preceeded by a backslash has raised a deprecation |
| 74 | warning since v5.18. Now they will be ignored. See L</qrE<sol>fooE<sol>x> |
| 75 | for the list of the five characters. |
| 76 | |
| 77 | =head2 Comment lines within S<C<(?[ ])>> now are ended only by a C<\n> |
| 78 | |
| 79 | S<C<(?[ ])>> is an experimental feature, introduced in v5.18. It operates |
| 80 | as if C</x> is always enabled. But there was a difference, comment |
| 81 | lines (following a C<#> character) were terminated by anything matching |
| 82 | C<\R> which includes all vertical whitespace, such as form feeds. For |
| 83 | consistency, this is now changed to match what terminates comment lines |
| 84 | outside S<C<(?[ ])>>, namely a C<\n> (even if escaped), which is the |
| 85 | same as what terminates a heredoc string and formats. |
| 86 | |
| 87 | =head1 Deprecations |
| 88 | |
| 89 | XXX Any deprecated features, syntax, modules etc. should be listed here. |
| 90 | |
| 91 | =head2 Using a NO-BREAK space in a character alias for C<\N{...}> is now |
| 92 | deprecated |
| 93 | |
| 94 | This non-graphic character is essentially indistinguishable from a |
| 95 | regular space, and so should not be allowed. See |
| 96 | L<charnames/CUSTOM ALIASES>. |
| 97 | |
| 98 | =head2 Module removals |
| 99 | |
| 100 | XXX Remove this section if inapplicable. |
| 101 | |
| 102 | The following modules will be removed from the core distribution in a |
| 103 | future release, and will at that time need to be installed from CPAN. |
| 104 | Distributions on CPAN which require these modules will need to list them as |
| 105 | prerequisites. |
| 106 | |
| 107 | The core versions of these modules will now issue C<"deprecated">-category |
| 108 | warnings to alert you to this fact. To silence these deprecation warnings, |
| 109 | install the modules in question from CPAN. |
| 110 | |
| 111 | Note that these are (with rare exceptions) fine modules that you are encouraged |
| 112 | to continue to use. Their disinclusion from core primarily hinges on their |
| 113 | necessity to bootstrapping a fully functional, CPAN-capable Perl installation, |
| 114 | not usually on concerns over their design. |
| 115 | |
| 116 | =over |
| 117 | |
| 118 | =item XXX |
| 119 | |
| 120 | XXX Note that deprecated modules should be listed here even if they are listed |
| 121 | as an updated module in the L</Modules and Pragmata> section. |
| 122 | |
| 123 | =back |
| 124 | |
| 125 | [ List each other deprecation as a =head2 entry ] |
| 126 | |
| 127 | =head1 Performance Enhancements |
| 128 | |
| 129 | XXX Changes which enhance performance without changing behaviour go here. |
| 130 | There may well be none in a stable release. |
| 131 | |
| 132 | [ List each enhancement as a =item entry ] |
| 133 | |
| 134 | =over 4 |
| 135 | |
| 136 | =item * |
| 137 | |
| 138 | XXX |
| 139 | |
| 140 | =back |
| 141 | |
| 142 | =head1 Modules and Pragmata |
| 143 | |
| 144 | XXX All changes to installed files in F<cpan/>, F<dist/>, F<ext/> and F<lib/> |
| 145 | go here. If Module::CoreList is updated, generate an initial draft of the |
| 146 | following sections using F<Porting/corelist-perldelta.pl>. A paragraph summary |
| 147 | for important changes should then be added by hand. In an ideal world, |
| 148 | dual-life modules would have a F<Changes> file that could be cribbed. |
| 149 | |
| 150 | [ Within each section, list entries as a =item entry ] |
| 151 | |
| 152 | =head2 New Modules and Pragmata |
| 153 | |
| 154 | =over 4 |
| 155 | |
| 156 | =item * |
| 157 | |
| 158 | XXX |
| 159 | |
| 160 | =back |
| 161 | |
| 162 | =head2 Updated Modules and Pragmata |
| 163 | |
| 164 | =over 4 |
| 165 | |
| 166 | =item * |
| 167 | |
| 168 | L<Carp> has been upgraded from version 1.3301 to 1.34. |
| 169 | |
| 170 | Carp::Heavy now ignores version mismatches with Carp if Carp is newer |
| 171 | than 1.12, since Carp::Heavy's guts were merged into Carp at that |
| 172 | point. |
| 173 | L<[perl #121574]|https://rt.perl.org/Ticket/Display.html?id=121574> |
| 174 | |
| 175 | =item * |
| 176 | |
| 177 | L<Encode> has been upgraded from version 2.60_01 to 2.62. |
| 178 | |
| 179 | B<piconv> now has better error handling when the encoding name is nonexistent, |
| 180 | and a build breakage when upgrading L<Encode> in perl-5.8.2 and earlier has |
| 181 | been fixed. |
| 182 | |
| 183 | =item * |
| 184 | |
| 185 | The libnet collection of modules has been upgraded from version 1.25 to 1.27. |
| 186 | |
| 187 | There are only whitespace changes to the installed files. |
| 188 | |
| 189 | =item * |
| 190 | |
| 191 | L<Math::BigInt> has been upgraded from version 1.9993 to 1.9994. |
| 192 | |
| 193 | Synchronize POD changes from the CPAN release. |
| 194 | |
| 195 | C<< Math::BigFloat->blog(x) >> would sometimes return blog(2*x) when |
| 196 | the accuracy was greater than 70 digits. |
| 197 | |
| 198 | The result of C<< Math::BigFloat->bdiv() >> in list context now |
| 199 | satisfies C<< x = quotient * divisor + remainder >>. |
| 200 | |
| 201 | =item * |
| 202 | |
| 203 | L<Math::BigRat> has been upgraded from version 0.2606 to 0.2607. |
| 204 | |
| 205 | Synchronize POD changes from the CPAN release. |
| 206 | |
| 207 | =item * |
| 208 | |
| 209 | L<perl5db.pl> has been upgraded from version 1.44 to 1.45. |
| 210 | |
| 211 | =item * |
| 212 | |
| 213 | A mismatch between the documentation and the code in utf8::downgrade() |
| 214 | was fixed in favour of the documentation. The optional second argument |
| 215 | is now correctly treated as a perl boolean (true/false semantics) and |
| 216 | not as an integer. |
| 217 | |
| 218 | =item * |
| 219 | |
| 220 | fork() in the debugger under C<tmux> will now create a new window for |
| 221 | the forked process. L<[perl |
| 222 | #121333]|https://rt.perl.org/Ticket/Display.html?id=121333> |
| 223 | |
| 224 | The debugger now saves the current working directory on startup and |
| 225 | restores it when you restart your program with C<R> or <rerun>. L<[perl |
| 226 | #121509]|https://rt.perl.org/Ticket/Display.html?id=121509> |
| 227 | |
| 228 | L<Unicode::Collate> has been upgraded from version 1.04 to 1.07. |
| 229 | |
| 230 | Version 0.67's improved discontiguous contractions is invalidated by default |
| 231 | and is supported as a parameter 'long_contraction'. |
| 232 | |
| 233 | =item * |
| 234 | |
| 235 | L<Unicode::Normalize> has been upgraded from version 1.17 to 1.18. |
| 236 | |
| 237 | The XSUB implementation has been removed in favour of pure Perl. |
| 238 | |
| 239 | =back |
| 240 | |
| 241 | =head2 Removed Modules and Pragmata |
| 242 | |
| 243 | =over 4 |
| 244 | |
| 245 | =item * |
| 246 | |
| 247 | XXX |
| 248 | |
| 249 | =back |
| 250 | |
| 251 | =head1 Documentation |
| 252 | |
| 253 | XXX Changes to files in F<pod/> go here. Consider grouping entries by |
| 254 | file and be sure to link to the appropriate page, e.g. L<perlfunc>. |
| 255 | |
| 256 | =head2 New Documentation |
| 257 | |
| 258 | XXX Changes which create B<new> files in F<pod/> go here. |
| 259 | |
| 260 | =head3 L<XXX> |
| 261 | |
| 262 | XXX Description of the purpose of the new file here |
| 263 | |
| 264 | =head2 Changes to Existing Documentation |
| 265 | |
| 266 | XXX Changes which significantly change existing files in F<pod/> go here. |
| 267 | However, any changes to F<pod/perldiag.pod> should go in the L</Diagnostics> |
| 268 | section. |
| 269 | |
| 270 | =head3 L<XXX> |
| 271 | |
| 272 | =over 4 |
| 273 | |
| 274 | =item * |
| 275 | |
| 276 | XXX Description of the change here |
| 277 | |
| 278 | =back |
| 279 | |
| 280 | =head1 Diagnostics |
| 281 | |
| 282 | The following additions or changes have been made to diagnostic output, |
| 283 | including warnings and fatal error messages. For the complete list of |
| 284 | diagnostic messages, see L<perldiag>. |
| 285 | |
| 286 | XXX New or changed warnings emitted by the core's C<C> code go here. Also |
| 287 | include any changes in L<perldiag> that reconcile it to the C<C> code. |
| 288 | |
| 289 | =head2 New Diagnostics |
| 290 | |
| 291 | XXX Newly added diagnostic messages go under here, separated into New Errors |
| 292 | and New Warnings |
| 293 | |
| 294 | =head3 New Errors |
| 295 | |
| 296 | =over 4 |
| 297 | |
| 298 | =item * |
| 299 | |
| 300 | XXX L<message|perldiag/"message"> |
| 301 | |
| 302 | =back |
| 303 | |
| 304 | =head3 New Warnings |
| 305 | |
| 306 | =over 4 |
| 307 | |
| 308 | =item * |
| 309 | |
| 310 | XXX L<message|perldiag/"message"> |
| 311 | |
| 312 | =back |
| 313 | |
| 314 | =head2 Changes to Existing Diagnostics |
| 315 | |
| 316 | XXX Changes (i.e. rewording) of diagnostic messages go here |
| 317 | |
| 318 | =over 4 |
| 319 | |
| 320 | =item * |
| 321 | |
| 322 | L<Unsuccessful %s on filename containing newline|perldiag/"Unsuccessful %s on filename containing newline"> |
| 323 | |
| 324 | This warning is now only produced when the newline is at the end of |
| 325 | the filename. |
| 326 | |
| 327 | =back |
| 328 | |
| 329 | =head1 Utility Changes |
| 330 | |
| 331 | XXX Changes to installed programs such as F<perlbug> and F<xsubpp> go here. |
| 332 | Most of these are built within the directories F<utils> and F<x2p>. |
| 333 | |
| 334 | [ List utility changes as a =head2 entry for each utility and =item |
| 335 | entries for each change |
| 336 | Use L<XXX> with program names to get proper documentation linking. ] |
| 337 | |
| 338 | =head2 L<XXX> |
| 339 | |
| 340 | =over 4 |
| 341 | |
| 342 | =item * |
| 343 | |
| 344 | XXX |
| 345 | |
| 346 | =back |
| 347 | |
| 348 | =head1 Configuration and Compilation |
| 349 | |
| 350 | XXX Changes to F<Configure>, F<installperl>, F<installman>, and analogous tools |
| 351 | go here. Any other changes to the Perl build process should be listed here. |
| 352 | However, any platform-specific changes should be listed in the |
| 353 | L</Platform Support> section, instead. |
| 354 | |
| 355 | [ List changes as a =item entry ]. |
| 356 | |
| 357 | =over 4 |
| 358 | |
| 359 | =item * |
| 360 | |
| 361 | XXX |
| 362 | |
| 363 | =back |
| 364 | |
| 365 | =head1 Testing |
| 366 | |
| 367 | XXX Any significant changes to the testing of a freshly built perl should be |
| 368 | listed here. Changes which create B<new> files in F<t/> go here as do any |
| 369 | large changes to the testing harness (e.g. when parallel testing was added). |
| 370 | Changes to existing files in F<t/> aren't worth summarizing, although the bugs |
| 371 | that they represent may be covered elsewhere. |
| 372 | |
| 373 | [ List each test improvement as a =item entry ] |
| 374 | |
| 375 | =over 4 |
| 376 | |
| 377 | =item * |
| 378 | |
| 379 | XXX |
| 380 | |
| 381 | =back |
| 382 | |
| 383 | =head1 Platform Support |
| 384 | |
| 385 | XXX Any changes to platform support should be listed in the sections below. |
| 386 | |
| 387 | [ Within the sections, list each platform as a =item entry with specific |
| 388 | changes as paragraphs below it. ] |
| 389 | |
| 390 | =head2 New Platforms |
| 391 | |
| 392 | XXX List any platforms that this version of perl compiles on, that previous |
| 393 | versions did not. These will either be enabled by new files in the F<hints/> |
| 394 | directories, or new subdirectories and F<README> files at the top level of the |
| 395 | source tree. |
| 396 | |
| 397 | =over 4 |
| 398 | |
| 399 | =item XXX-some-platform |
| 400 | |
| 401 | XXX |
| 402 | |
| 403 | =back |
| 404 | |
| 405 | =head2 Discontinued Platforms |
| 406 | |
| 407 | XXX List any platforms that this version of perl no longer compiles on. |
| 408 | |
| 409 | =over 4 |
| 410 | |
| 411 | =item XXX-some-platform |
| 412 | |
| 413 | XXX |
| 414 | |
| 415 | =back |
| 416 | |
| 417 | =head2 Platform-Specific Notes |
| 418 | |
| 419 | XXX List any changes for specific platforms. This could include configuration |
| 420 | and compilation changes or changes in portability/compatibility. However, |
| 421 | changes within modules for platforms should generally be listed in the |
| 422 | L</Modules and Pragmata> section. |
| 423 | |
| 424 | =over 4 |
| 425 | |
| 426 | =item XXX-some-platform |
| 427 | |
| 428 | XXX |
| 429 | |
| 430 | =back |
| 431 | |
| 432 | =head1 Internal Changes |
| 433 | |
| 434 | XXX Changes which affect the interface available to C<XS> code go here. Other |
| 435 | significant internal changes for future core maintainers should be noted as |
| 436 | well. |
| 437 | |
| 438 | =over 4 |
| 439 | |
| 440 | =item * |
| 441 | |
| 442 | The deprecated variable C<PL_sv_objcount> has been removed. |
| 443 | |
| 444 | =back |
| 445 | |
| 446 | =head1 Selected Bug Fixes |
| 447 | |
| 448 | XXX Important bug fixes in the core language are summarized here. Bug fixes in |
| 449 | files in F<ext/> and F<lib/> are best summarized in L</Modules and Pragmata>. |
| 450 | |
| 451 | [ List each fix as a =item entry ] |
| 452 | |
| 453 | =over 4 |
| 454 | |
| 455 | =item * |
| 456 | |
| 457 | index() and rindex() no longer crash when used on strings over 2GB in |
| 458 | size. |
| 459 | L<[perl #121562]|https://rt.perl.org/Ticket/Display.html?id=121562>. |
| 460 | |
| 461 | =back |
| 462 | |
| 463 | =head1 Known Problems |
| 464 | |
| 465 | XXX Descriptions of platform agnostic bugs we know we can't fix go here. Any |
| 466 | tests that had to be C<TODO>ed for the release would be noted here. Unfixed |
| 467 | platform specific bugs also go here. |
| 468 | |
| 469 | [ List each fix as a =item entry ] |
| 470 | |
| 471 | =over 4 |
| 472 | |
| 473 | =item * |
| 474 | |
| 475 | XXX |
| 476 | |
| 477 | =back |
| 478 | |
| 479 | =head1 Errata From Previous Releases |
| 480 | |
| 481 | =over 4 |
| 482 | |
| 483 | =item * |
| 484 | |
| 485 | XXX Add anything here that we forgot to add, or were mistaken about, in |
| 486 | the perldelta of a previous release. |
| 487 | |
| 488 | =back |
| 489 | |
| 490 | =head1 Obituary |
| 491 | |
| 492 | XXX If any significant core contributor has died, we've added a short obituary |
| 493 | here. |
| 494 | |
| 495 | =head1 Acknowledgements |
| 496 | |
| 497 | XXX Generate this with: |
| 498 | |
| 499 | perl Porting/acknowledgements.pl v5.21.1..HEAD |
| 500 | |
| 501 | =head1 Reporting Bugs |
| 502 | |
| 503 | If you find what you think is a bug, you might check the articles recently |
| 504 | posted to the comp.lang.perl.misc newsgroup and the perl bug database at |
| 505 | https://rt.perl.org/ . There may also be information at |
| 506 | http://www.perl.org/ , the Perl Home Page. |
| 507 | |
| 508 | If you believe you have an unreported bug, please run the L<perlbug> program |
| 509 | included with your release. Be sure to trim your bug down to a tiny but |
| 510 | sufficient test case. Your bug report, along with the output of C<perl -V>, |
| 511 | will be sent off to perlbug@perl.org to be analysed by the Perl porting team. |
| 512 | |
| 513 | If the bug you are reporting has security implications, which make it |
| 514 | inappropriate to send to a publicly archived mailing list, then please send it |
| 515 | to perl5-security-report@perl.org. This points to a closed subscription |
| 516 | unarchived mailing list, which includes all the core committers, who will be |
| 517 | able to help assess the impact of issues, figure out a resolution, and help |
| 518 | co-ordinate the release of patches to mitigate or fix the problem across all |
| 519 | platforms on which Perl is supported. Please only use this address for |
| 520 | security issues in the Perl core, not for modules independently distributed on |
| 521 | CPAN. |
| 522 | |
| 523 | =head1 SEE ALSO |
| 524 | |
| 525 | The F<Changes> file for an explanation of how to view exhaustive details on |
| 526 | what changed. |
| 527 | |
| 528 | The F<INSTALL> file for how to build Perl. |
| 529 | |
| 530 | The F<README> file for general stuff. |
| 531 | |
| 532 | The F<Artistic> and F<Copying> files for copyright information. |
| 533 | |
| 534 | =cut |