| 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 v5.19.2 |
| 9 | |
| 10 | =head1 DESCRIPTION |
| 11 | |
| 12 | This document describes differences between the 5.19.1 release and the 5.19.2 |
| 13 | release. |
| 14 | |
| 15 | If you are upgrading from an earlier release such as 5.19.0, first read |
| 16 | L<perl5191delta>, which describes differences between 5.19.0 and 5.19.1. |
| 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 | =head2 More consistent prototype parsing |
| 29 | |
| 30 | Multiple semicolons in subroutine prototypes have long been tolerated and |
| 31 | treated as a single semicolon. There was one case where this did not |
| 32 | happen. A subroutine whose prototype begins with "*" or ";*" can affect |
| 33 | whether a bareword is considered a method name or sub call. This now |
| 34 | applies also to ";;;*". |
| 35 | |
| 36 | Whitespace has long been allowed inside subroutine prototypes, so |
| 37 | C<sub( $ $ )> is equivalent to C<sub($$)>. But it was stripped when the |
| 38 | subroutine was parse. Hence, whitespace was I<not> allowed in prototypes |
| 39 | set by C<Scalar::Util::set_prototype>. Now it is permitted, and the parser |
| 40 | no longer strips whitespace. This means C<prototype &mysub> returns the |
| 41 | original prototype, whitespace and all. |
| 42 | |
| 43 | =head1 Security |
| 44 | |
| 45 | XXX Any security-related notices go here. In particular, any security |
| 46 | vulnerabilities closed should be noted here rather than in the |
| 47 | L</Selected Bug Fixes> section. |
| 48 | |
| 49 | [ List each security issue as a =head2 entry ] |
| 50 | |
| 51 | =head1 Incompatible Changes |
| 52 | |
| 53 | XXX For a release on a stable branch, this section aspires to be: |
| 54 | |
| 55 | There are no changes intentionally incompatible with 5.XXX.XXX |
| 56 | If any exist, they are bugs, and we request that you submit a |
| 57 | report. See L</Reporting Bugs> below. |
| 58 | |
| 59 | [ List each incompatible change as a =head2 entry ] |
| 60 | |
| 61 | =head1 Deprecations |
| 62 | |
| 63 | XXX Any deprecated features, syntax, modules etc. should be listed here. |
| 64 | |
| 65 | =head2 Module removals |
| 66 | |
| 67 | XXX Remove this section if inapplicable. |
| 68 | |
| 69 | The following modules will be removed from the core distribution in a |
| 70 | future release, and will at that time need to be installed from CPAN. |
| 71 | Distributions on CPAN which require these modules will need to list them as |
| 72 | prerequisites. |
| 73 | |
| 74 | The core versions of these modules will now issue C<"deprecated">-category |
| 75 | warnings to alert you to this fact. To silence these deprecation warnings, |
| 76 | install the modules in question from CPAN. |
| 77 | |
| 78 | Note that these are (with rare exceptions) fine modules that you are encouraged |
| 79 | to continue to use. Their disinclusion from core primarily hinges on their |
| 80 | necessity to bootstrapping a fully functional, CPAN-capable Perl installation, |
| 81 | not usually on concerns over their design. |
| 82 | |
| 83 | =over |
| 84 | |
| 85 | XXX Note that deprecated modules should be listed here even if they are listed |
| 86 | as an updated module in the L</Modules and Pragmata> section. |
| 87 | |
| 88 | =back |
| 89 | |
| 90 | [ List each other deprecation as a =head2 entry ] |
| 91 | |
| 92 | =head1 Performance Enhancements |
| 93 | |
| 94 | XXX Changes which enhance performance without changing behaviour go here. |
| 95 | There may well be none in a stable release. |
| 96 | |
| 97 | [ List each enhancement as a =item entry ] |
| 98 | |
| 99 | =over 4 |
| 100 | |
| 101 | =item * |
| 102 | |
| 103 | XXX |
| 104 | |
| 105 | =back |
| 106 | |
| 107 | =head1 Modules and Pragmata |
| 108 | |
| 109 | XXX All changes to installed files in F<cpan/>, F<dist/>, F<ext/> and F<lib/> |
| 110 | go here. If Module::CoreList is updated, generate an initial draft of the |
| 111 | following sections using F<Porting/corelist-perldelta.pl>, which prints stub |
| 112 | entries to STDOUT. Results can be pasted in place of the '=head2' entries |
| 113 | below. A paragraph summary for important changes should then be added by hand. |
| 114 | In an ideal world, dual-life modules would have a F<Changes> file that could be |
| 115 | cribbed. |
| 116 | |
| 117 | [ Within each section, list entries as a =item entry ] |
| 118 | |
| 119 | =head2 New Modules and Pragmata |
| 120 | |
| 121 | =over 4 |
| 122 | |
| 123 | =item * |
| 124 | |
| 125 | XXX |
| 126 | |
| 127 | =back |
| 128 | |
| 129 | =head2 Updated Modules and Pragmata |
| 130 | |
| 131 | =over 4 |
| 132 | |
| 133 | =item * |
| 134 | |
| 135 | L<ExtUtils::Embed> has been upgraded from version 1.30 to 1.31 |
| 136 | |
| 137 | The generated C<C> code now incorporates bug fixes present in |
| 138 | F<miniperlmain.c>, and has whitespace changes. It now uses |
| 139 | C<#include "..."> for header files instead of C<< #include <...> >>. |
| 140 | This should not make any difference, unless programs embedding C<libperl> |
| 141 | happen to have local and incompatible files named F<EXTERN.h>, F<XSUB.h> or |
| 142 | F<perl.h>, as these will now be picked up instead of the installed Perl |
| 143 | headers. |
| 144 | |
| 145 | =item * |
| 146 | |
| 147 | L<ExtUtils::Miniperl> has been upgraded and given a version of 1. |
| 148 | Previously it did not have a version number. |
| 149 | |
| 150 | C<writemain()> now takes an optional first argument. A reference to a scalar |
| 151 | is treated as a filename to be opened and written to. Any other reference is |
| 152 | used as the filehandle to write to. Otherwise the existing default remains, |
| 153 | to write to C<STDOUT>. |
| 154 | |
| 155 | C<writemain()> has been refactored to use functions from L<ExtUtils::Embed>, |
| 156 | reducing code size and duplication. The internal function C<canon()> has been |
| 157 | deleted. |
| 158 | |
| 159 | =item * |
| 160 | |
| 161 | L<POSIX> has been upgraded from version 1.33 to 1.34. |
| 162 | |
| 163 | C<POSIX::AUTOLOAD> will no longer infinitely recurse if the shared |
| 164 | object fails to load. |
| 165 | |
| 166 | =item * |
| 167 | |
| 168 | L<Storable> has been upgraded from version 2.43 to 2.44. |
| 169 | |
| 170 | Calling C<STORABLE_attach> hooks no longer leaks memory. [perl #118829] |
| 171 | |
| 172 | =back |
| 173 | |
| 174 | =head2 Removed Modules and Pragmata |
| 175 | |
| 176 | =over 4 |
| 177 | |
| 178 | =item * |
| 179 | |
| 180 | XXX |
| 181 | |
| 182 | =back |
| 183 | |
| 184 | =head1 Documentation |
| 185 | |
| 186 | XXX Changes to files in F<pod/> go here. Consider grouping entries by |
| 187 | file and be sure to link to the appropriate page, e.g. L<perlfunc>. |
| 188 | |
| 189 | =head2 New Documentation |
| 190 | |
| 191 | XXX Changes which create B<new> files in F<pod/> go here. |
| 192 | |
| 193 | =head3 L<XXX> |
| 194 | |
| 195 | XXX Description of the purpose of the new file here |
| 196 | |
| 197 | =head2 Changes to Existing Documentation |
| 198 | |
| 199 | XXX Changes which significantly change existing files in F<pod/> go here. |
| 200 | However, any changes to F<pod/perldiag.pod> should go in the L</Diagnostics> |
| 201 | section. |
| 202 | |
| 203 | =head3 L<perlexperiment> |
| 204 | |
| 205 | =over 4 |
| 206 | |
| 207 | =item * |
| 208 | |
| 209 | Code in regular expressions, regular expression backtracking verbs, |
| 210 | and lvalue subroutines are no longer listed as experimental. (This |
| 211 | also affects L<perlre> and L<perlsub>.) |
| 212 | |
| 213 | =back |
| 214 | |
| 215 | =head1 Diagnostics |
| 216 | |
| 217 | The following additions or changes have been made to diagnostic output, |
| 218 | including warnings and fatal error messages. For the complete list of |
| 219 | diagnostic messages, see L<perldiag>. |
| 220 | |
| 221 | XXX New or changed warnings emitted by the core's C<C> code go here. Also |
| 222 | include any changes in L<perldiag> that reconcile it to the C<C> code. |
| 223 | |
| 224 | =head2 New Diagnostics |
| 225 | |
| 226 | XXX Newly added diagnostic messages go under here, separated into New Errors |
| 227 | and New Warnings |
| 228 | |
| 229 | =head3 New Errors |
| 230 | |
| 231 | =over 4 |
| 232 | |
| 233 | =item * |
| 234 | |
| 235 | XXX L<message|perldiag/"message"> |
| 236 | |
| 237 | =back |
| 238 | |
| 239 | =head3 New Warnings |
| 240 | |
| 241 | =over 4 |
| 242 | |
| 243 | =item * |
| 244 | |
| 245 | XXX L<message|perldiag/"message"> |
| 246 | |
| 247 | =back |
| 248 | |
| 249 | =head2 Changes to Existing Diagnostics |
| 250 | |
| 251 | XXX Changes (i.e. rewording) of diagnostic messages go here |
| 252 | |
| 253 | =over 4 |
| 254 | |
| 255 | =item * |
| 256 | |
| 257 | Under rare circumstances, one could get a "Can't coerce readonly REF to |
| 258 | string" instead of the customary "Modification of a read-only value". This |
| 259 | alternate error message has been removed. |
| 260 | |
| 261 | =back |
| 262 | |
| 263 | =head1 Utility Changes |
| 264 | |
| 265 | XXX Changes to installed programs such as F<perlbug> and F<xsubpp> go here. |
| 266 | Most of these are built within the directories F<utils> and F<x2p>. |
| 267 | |
| 268 | [ List utility changes as a =head3 entry for each utility and =item |
| 269 | entries for each change |
| 270 | Use L<XXX> with program names to get proper documentation linking. ] |
| 271 | |
| 272 | =head3 L<XXX> |
| 273 | |
| 274 | =over 4 |
| 275 | |
| 276 | =item * |
| 277 | |
| 278 | XXX |
| 279 | |
| 280 | =back |
| 281 | |
| 282 | =head1 Configuration and Compilation |
| 283 | |
| 284 | XXX Changes to F<Configure>, F<installperl>, F<installman>, and analogous tools |
| 285 | go here. Any other changes to the Perl build process should be listed here. |
| 286 | However, any platform-specific changes should be listed in the |
| 287 | L</Platform Support> section, instead. |
| 288 | |
| 289 | [ List changes as a =item entry ]. |
| 290 | |
| 291 | =over 4 |
| 292 | |
| 293 | =item * |
| 294 | |
| 295 | F<installperl> and F<installman>'s option handling has been refactored to use |
| 296 | L<Getopt::Long>. Both are used by the F<Makefile> C<install> targets, and |
| 297 | are not installed, so these changes are only likely to affect custom |
| 298 | installation scripts. |
| 299 | |
| 300 | =over 4 |
| 301 | |
| 302 | =item * |
| 303 | |
| 304 | single letter options now also have long names |
| 305 | |
| 306 | =item * |
| 307 | |
| 308 | invalid options are now rejected |
| 309 | |
| 310 | =item * |
| 311 | |
| 312 | command line arguments that are not options are now rejected |
| 313 | |
| 314 | =item * |
| 315 | |
| 316 | Each now has a C<--help> option to display the usage message. |
| 317 | |
| 318 | =back |
| 319 | |
| 320 | The behaviour for all valid documented invocations is unchanged. |
| 321 | |
| 322 | =back |
| 323 | |
| 324 | =head1 Testing |
| 325 | |
| 326 | XXX Any significant changes to the testing of a freshly built perl should be |
| 327 | listed here. Changes which create B<new> files in F<t/> go here as do any |
| 328 | large changes to the testing harness (e.g. when parallel testing was added). |
| 329 | Changes to existing files in F<t/> aren't worth summarizing, although the bugs |
| 330 | that they represent may be covered elsewhere. |
| 331 | |
| 332 | [ List each test improvement as a =item entry ] |
| 333 | |
| 334 | =over 4 |
| 335 | |
| 336 | =item * |
| 337 | |
| 338 | XXX |
| 339 | |
| 340 | =back |
| 341 | |
| 342 | =head1 Platform Support |
| 343 | |
| 344 | XXX Any changes to platform support should be listed in the sections below. |
| 345 | |
| 346 | [ Within the sections, list each platform as a =item entry with specific |
| 347 | changes as paragraphs below it. ] |
| 348 | |
| 349 | =head2 New Platforms |
| 350 | |
| 351 | XXX List any platforms that this version of perl compiles on, that previous |
| 352 | versions did not. These will either be enabled by new files in the F<hints/> |
| 353 | directories, or new subdirectories and F<README> files at the top level of the |
| 354 | source tree. |
| 355 | |
| 356 | =over 4 |
| 357 | |
| 358 | =item XXX-some-platform |
| 359 | |
| 360 | XXX |
| 361 | |
| 362 | =back |
| 363 | |
| 364 | =head2 Discontinued Platforms |
| 365 | |
| 366 | XXX List any platforms that this version of perl no longer compiles on. |
| 367 | |
| 368 | =over 4 |
| 369 | |
| 370 | =item XXX-some-platform |
| 371 | |
| 372 | XXX |
| 373 | |
| 374 | =back |
| 375 | |
| 376 | =head2 Platform-Specific Notes |
| 377 | |
| 378 | XXX List any changes for specific platforms. This could include configuration |
| 379 | and compilation changes or changes in portability/compatibility. However, |
| 380 | changes within modules for platforms should generally be listed in the |
| 381 | L</Modules and Pragmata> section. |
| 382 | |
| 383 | =over 4 |
| 384 | |
| 385 | =item MidnightBSD |
| 386 | |
| 387 | C<objformat> was removed from version 0.4-RELEASE of MidnightBSD and had been |
| 388 | deprecated on earlier versions. This caused the build environment to be |
| 389 | erroneously configured for C<a.out> rather than C<elf>. This has been now |
| 390 | been corrected. |
| 391 | |
| 392 | =back |
| 393 | |
| 394 | =head1 Internal Changes |
| 395 | |
| 396 | XXX Changes which affect the interface available to C<XS> code go here. Other |
| 397 | significant internal changes for future core maintainers should be noted as |
| 398 | well. |
| 399 | |
| 400 | [ List each change as a =item entry ] |
| 401 | |
| 402 | =over 4 |
| 403 | |
| 404 | =item * |
| 405 | |
| 406 | The Makefile shortcut targets for many rarely (or never) used testing and |
| 407 | profiling targets have been removed, or merged into the only other Makefile |
| 408 | target that uses them. Specifically, these targets are gone, along with |
| 409 | documentation that referenced them or explained how to use them: |
| 410 | |
| 411 | check.third check.utf16 check.utf8 coretest minitest.prep |
| 412 | minitest.utf16 perl.config.dashg perl.config.dashpg |
| 413 | perl.config.gcov perl.gcov perl.gprof perl.gprof.config |
| 414 | perl.pixie perl.pixie.atom perl.pixie.config perl.pixie.irix |
| 415 | perl.third perl.third.config perl.valgrind.config purecovperl |
| 416 | pureperl quantperl test.deparse test.taintwarn test.third |
| 417 | test.torture test.utf16 test.utf8 test_notty.deparse |
| 418 | test_notty.third test_notty.valgrind test_prep.third |
| 419 | test_prep.valgrind torturetest ucheck ucheck.third ucheck.utf16 |
| 420 | ucheck.valgrind utest utest.third utest.utf16 utest.valgrind |
| 421 | |
| 422 | It's still possible to run the relevant commands by "hand" - no underlying |
| 423 | functionality has been removed. |
| 424 | |
| 425 | =item * |
| 426 | |
| 427 | It is now possible to keep Perl from initializing locale handling. |
| 428 | For the most part, Perl doesn't pay attention to locale. (See |
| 429 | L<perllocale>.) Nonetheless, until now, on startup, it has always |
| 430 | initialized locale handling to the system default, just in case the |
| 431 | program being executed ends up using locales. (This is one of the first |
| 432 | things a locale-aware program should do, long before Perl knows if it |
| 433 | will actually be needed or not.) This works well except when Perl is |
| 434 | embedded in another application which wants a locale that isn't the |
| 435 | system default. Now, if the environment variable |
| 436 | C<PERL_SKIP_LOCALE_INIT> is set at the time Perl is started, this |
| 437 | initialization step is skipped. Prior to this, on Windows platforms, |
| 438 | the only workaround for this deficiency was to use a hacked-up copy of |
| 439 | internal Perl code. Applications that need to use older Perls can |
| 440 | discover if the embedded Perl they are using needs the workaround by |
| 441 | testing that the C preprocessor symbol C<HAS_SKIP_LOCALE_INIT> is not |
| 442 | defined. (RT #38193) |
| 443 | |
| 444 | =item * |
| 445 | |
| 446 | C<BmRARE> and C<BmPREVIOUS> have been removed. They were not used anywhere |
| 447 | and are not part of the API. For XS modules, they are now #defined as 0. |
| 448 | |
| 449 | =item * |
| 450 | |
| 451 | C<sv_force_normal>, which usually croaks on read-only values, used to allow |
| 452 | read-only values to be modified at compile time. This has been changed to |
| 453 | croak on read-only values regardless. This change uncovered several core |
| 454 | bugs. |
| 455 | |
| 456 | =back |
| 457 | |
| 458 | =head1 Selected Bug Fixes |
| 459 | |
| 460 | XXX Important bug fixes in the core language are summarized here. Bug fixes in |
| 461 | files in F<ext/> and F<lib/> are best summarized in L</Modules and Pragmata>. |
| 462 | |
| 463 | [ List each fix as a =item entry ] |
| 464 | |
| 465 | =over 4 |
| 466 | |
| 467 | =item * |
| 468 | |
| 469 | There have been several fixes related to Perl's handling of locales. perl |
| 470 | #38193 was described above in L</Internal Changes>. |
| 471 | Also fixed is #112208 in which the error string in C<$!> displayed as |
| 472 | garbage in many UTF-8 locales; |
| 473 | #118197, where the radix (decimal point) character had to be an ASCII |
| 474 | character (which doesn't work for some non-Western languages); |
| 475 | and #115808, in which C<POSIX::setlocale()> on failure returned an |
| 476 | C<undef> which didn't warn about not being defined even if those |
| 477 | warnings were enabled. |
| 478 | |
| 479 | =item * |
| 480 | |
| 481 | The dtrace sub-entry probe now works with lexical subs, instead of |
| 482 | crashing [perl #118305]. |
| 483 | |
| 484 | =item * |
| 485 | |
| 486 | Compiling a C<split> operator whose third argument is a named constant |
| 487 | evaulating to 0 no longer causes the constant's value to change. |
| 488 | |
| 489 | =item * |
| 490 | |
| 491 | A named constant used as the second argument to C<index> no longer gets |
| 492 | coerced to a string if it is a reference, regular expression, dualvar, etc. |
| 493 | |
| 494 | =item * |
| 495 | |
| 496 | A named constant evaluating to the undefined value used as the second |
| 497 | argument to C<index> no longer produces "uninitialized" warnings at compile |
| 498 | time. It will still produce them at run time. |
| 499 | |
| 500 | =item * |
| 501 | |
| 502 | When a scalar was returned from a subroutine in @INC, the referenced scalar |
| 503 | was magically converted into an IO thingy, possibly resulting in "Bizarre |
| 504 | copy" errors if that scalar continued to be used elsewhere. Now Perl uses |
| 505 | an internal copy of the scalar instead. |
| 506 | |
| 507 | =back |
| 508 | |
| 509 | =head1 Known Problems |
| 510 | |
| 511 | XXX Descriptions of platform agnostic bugs we know we can't fix go here. Any |
| 512 | tests that had to be C<TODO>ed for the release would be noted here. Unfixed |
| 513 | platform specific bugs also go here. |
| 514 | |
| 515 | [ List each fix as a =item entry ] |
| 516 | |
| 517 | =over 4 |
| 518 | |
| 519 | =item * |
| 520 | |
| 521 | XXX |
| 522 | |
| 523 | =back |
| 524 | |
| 525 | =head1 Obituary |
| 526 | |
| 527 | XXX If any significant core contributor has died, we've added a short obituary |
| 528 | here. |
| 529 | |
| 530 | =head1 Acknowledgements |
| 531 | |
| 532 | XXX Generate this with: |
| 533 | |
| 534 | perl Porting/acknowledgements.pl v5.19.1..HEAD |
| 535 | |
| 536 | =head1 Reporting Bugs |
| 537 | |
| 538 | If you find what you think is a bug, you might check the articles recently |
| 539 | posted to the comp.lang.perl.misc newsgroup and the perl bug database at |
| 540 | http://rt.perl.org/perlbug/ . There may also be information at |
| 541 | http://www.perl.org/ , the Perl Home Page. |
| 542 | |
| 543 | If you believe you have an unreported bug, please run the L<perlbug> program |
| 544 | included with your release. Be sure to trim your bug down to a tiny but |
| 545 | sufficient test case. Your bug report, along with the output of C<perl -V>, |
| 546 | will be sent off to perlbug@perl.org to be analysed by the Perl porting team. |
| 547 | |
| 548 | If the bug you are reporting has security implications, which make it |
| 549 | inappropriate to send to a publicly archived mailing list, then please send it |
| 550 | to perl5-security-report@perl.org. This points to a closed subscription |
| 551 | unarchived mailing list, which includes all the core committers, who will be |
| 552 | able to help assess the impact of issues, figure out a resolution, and help |
| 553 | co-ordinate the release of patches to mitigate or fix the problem across all |
| 554 | platforms on which Perl is supported. Please only use this address for |
| 555 | security issues in the Perl core, not for modules independently distributed on |
| 556 | CPAN. |
| 557 | |
| 558 | =head1 SEE ALSO |
| 559 | |
| 560 | The F<Changes> file for an explanation of how to view exhaustive details on |
| 561 | what changed. |
| 562 | |
| 563 | The F<INSTALL> file for how to build Perl. |
| 564 | |
| 565 | The F<README> file for general stuff. |
| 566 | |
| 567 | The F<Artistic> and F<Copying> files for copyright information. |
| 568 | |
| 569 | =cut |