| 1 | =encoding utf8 |
| 2 | |
| 3 | =head1 NAME |
| 4 | |
| 5 | [ this is a template for a new perldelta file. Any text flagged as |
| 6 | XXX needs to be processed before release. ] |
| 7 | |
| 8 | perldelta - what is new for perl v5.17.2 |
| 9 | |
| 10 | =head1 DESCRIPTION |
| 11 | |
| 12 | This document describes differences between the 5.17.1 release and |
| 13 | the 5.17.2 release. |
| 14 | |
| 15 | If you are upgrading from an earlier release such as 5.17.0, first read |
| 16 | L<perl5171delta>, which describes differences between 5.17.0 and |
| 17 | 5.17.1. |
| 18 | |
| 19 | =head1 Notice |
| 20 | |
| 21 | XXX Any important notices here |
| 22 | |
| 23 | =head1 Core Enhancements |
| 24 | |
| 25 | XXX New core language features go here. Summarise user-visible core language |
| 26 | enhancements. Particularly prominent performance optimisations could go |
| 27 | here, but most should go in the L</Performance Enhancements> section. |
| 28 | |
| 29 | [ List each enhancement as a =head2 entry ] |
| 30 | |
| 31 | =head1 Security |
| 32 | |
| 33 | XXX Any security-related notices go here. In particular, any security |
| 34 | vulnerabilities closed should be noted here rather than in the |
| 35 | L</Selected Bug Fixes> section. |
| 36 | |
| 37 | [ List each security issue as a =head2 entry ] |
| 38 | |
| 39 | =head1 Incompatible Changes |
| 40 | |
| 41 | XXX For a release on a stable branch, this section aspires to be: |
| 42 | |
| 43 | There are no changes intentionally incompatible with 5.XXX.XXX |
| 44 | If any exist, they are bugs, and we request that you submit a |
| 45 | report. See L</Reporting Bugs> below. |
| 46 | |
| 47 | [ List each incompatible change as a =head2 entry ] |
| 48 | |
| 49 | =head1 Deprecations |
| 50 | |
| 51 | XXX Any deprecated features, syntax, modules etc. should be listed here. |
| 52 | In particular, deprecated modules should be listed here even if they are |
| 53 | listed as an updated module in the L</Modules and Pragmata> section. |
| 54 | |
| 55 | [ List each deprecation as a =head2 entry ] |
| 56 | |
| 57 | =head1 Performance Enhancements |
| 58 | |
| 59 | XXX Changes which enhance performance without changing behaviour go here. There |
| 60 | may well be none in a stable release. |
| 61 | |
| 62 | [ List each enhancement as a =item entry ] |
| 63 | |
| 64 | =over 4 |
| 65 | |
| 66 | =item * |
| 67 | |
| 68 | XXX |
| 69 | |
| 70 | =back |
| 71 | |
| 72 | =head1 Modules and Pragmata |
| 73 | |
| 74 | XXX All changes to installed files in F<cpan/>, F<dist/>, F<ext/> and F<lib/> |
| 75 | go here. If Module::CoreList is updated, generate an initial draft of the |
| 76 | following sections using F<Porting/corelist-perldelta.pl>, which prints stub |
| 77 | entries to STDOUT. Results can be pasted in place of the '=head2' entries |
| 78 | below. A paragraph summary for important changes should then be added by hand. |
| 79 | In an ideal world, dual-life modules would have a F<Changes> file that could be |
| 80 | cribbed. |
| 81 | |
| 82 | [ Within each section, list entries as a =item entry ] |
| 83 | |
| 84 | =head2 New Modules and Pragmata |
| 85 | |
| 86 | =over 4 |
| 87 | |
| 88 | =item * |
| 89 | |
| 90 | XXX |
| 91 | |
| 92 | =back |
| 93 | |
| 94 | =head2 Updated Modules and Pragmata |
| 95 | |
| 96 | =over 4 |
| 97 | |
| 98 | =item * |
| 99 | |
| 100 | L<File::stat> has been upgraded from version 1.06 to 1.07. |
| 101 | |
| 102 | Previously C<File::stat>'s overloaded C<-x> and C<-X> operators did not give |
| 103 | the correct results for directories or executable files when running as |
| 104 | root. They had been treating executable permissions for root just like for |
| 105 | any other user, performing group membership tests I<etc> for files not owned |
| 106 | by root. They now follow the correct Unix behaviour - for a directory they |
| 107 | are always true, and for a file if any of the three execute permission bits |
| 108 | are set then they report that root can execute the file. Perl's builtin |
| 109 | C<-x> and C<-X> operators have always been correct. |
| 110 | |
| 111 | =item * |
| 112 | |
| 113 | L<Tie::StdHandle> has been upgraded from version 4.2 to 4.3. |
| 114 | |
| 115 | C<READ> now respects the offset argument to C<read> [perl #112826]. |
| 116 | |
| 117 | =item * |
| 118 | |
| 119 | L<IO> has been upgraded from version 1.25_07 to 1.25_08. |
| 120 | |
| 121 | L<IO::Socket> tries harder to cache or otherwise fetch socket |
| 122 | information. |
| 123 | |
| 124 | =item * |
| 125 | |
| 126 | L<Storable> has been upgraded from version 2.36 to 2.37. |
| 127 | |
| 128 | Restricted hashes were not always thawed correctly [perl #73972]. |
| 129 | |
| 130 | Storable would croak when freezing a blessed REF object with a |
| 131 | C<STORABLE_freeze()> method [perl #113880]. |
| 132 | |
| 133 | =back |
| 134 | |
| 135 | =head2 Removed Modules and Pragmata |
| 136 | |
| 137 | =over 4 |
| 138 | |
| 139 | =item * |
| 140 | |
| 141 | XXX |
| 142 | |
| 143 | =back |
| 144 | |
| 145 | =head1 Documentation |
| 146 | |
| 147 | XXX Changes to files in F<pod/> go here. Consider grouping entries by |
| 148 | file and be sure to link to the appropriate page, e.g. L<perlfunc>. |
| 149 | |
| 150 | =head2 New Documentation |
| 151 | |
| 152 | XXX Changes which create B<new> files in F<pod/> go here. |
| 153 | |
| 154 | =head3 L<XXX> |
| 155 | |
| 156 | XXX Description of the purpose of the new file here |
| 157 | |
| 158 | =head2 Changes to Existing Documentation |
| 159 | |
| 160 | XXX Changes which significantly change existing files in F<pod/> go here. |
| 161 | However, any changes to F<pod/perldiag.pod> should go in the L</Diagnostics> |
| 162 | section. |
| 163 | |
| 164 | =head3 L<perlfunc> |
| 165 | |
| 166 | =over 4 |
| 167 | |
| 168 | =item * |
| 169 | |
| 170 | Clarified documentation of C<our>. |
| 171 | |
| 172 | =back |
| 173 | |
| 174 | =head1 Diagnostics |
| 175 | |
| 176 | The following additions or changes have been made to diagnostic output, |
| 177 | including warnings and fatal error messages. For the complete list of |
| 178 | diagnostic messages, see L<perldiag>. |
| 179 | |
| 180 | XXX New or changed warnings emitted by the core's C<C> code go here. Also |
| 181 | include any changes in L<perldiag> that reconcile it to the C<C> code. |
| 182 | |
| 183 | [ Within each section, list entries as a =item entry that links to perldiag, |
| 184 | e.g. |
| 185 | |
| 186 | =item * |
| 187 | |
| 188 | L<Invalid version object|perldiag/"Invalid version object"> |
| 189 | ] |
| 190 | |
| 191 | =head2 New Diagnostics |
| 192 | |
| 193 | XXX Newly added diagnostic messages go here |
| 194 | |
| 195 | =head3 New Errors |
| 196 | |
| 197 | =over 4 |
| 198 | |
| 199 | =item * |
| 200 | |
| 201 | L<Group name must start with a non-digit word character in regex; marked by <-- HERE in mE<sol>%sE<sol>|perldiag/"Group name must start with a non-digit word character in regex; marked by <-- HERE in m/%s/"> |
| 202 | |
| 203 | This error has been added for C<(?&0)>, which is invalid. It used to |
| 204 | produce an incomprehensible error message [perl #101666]. |
| 205 | |
| 206 | =back |
| 207 | |
| 208 | =head3 New Warnings |
| 209 | |
| 210 | =over 4 |
| 211 | |
| 212 | =item * |
| 213 | |
| 214 | C<chr()> now warns when passed a negative value [perl #83048]. |
| 215 | |
| 216 | =item * |
| 217 | |
| 218 | C<srand()> now warns when passed a value that doesn't fit in a C<UV> (since the |
| 219 | value will be truncated rather than overflowing) [perl #40605]. |
| 220 | |
| 221 | =item * |
| 222 | |
| 223 | Running perl with the C<-i> flag now warns if no input files are provided on |
| 224 | the command line [perl #113410]. |
| 225 | |
| 226 | =back |
| 227 | |
| 228 | =head2 Changes to Existing Diagnostics |
| 229 | |
| 230 | XXX Changes (i.e. rewording) of diagnostic messages go here |
| 231 | |
| 232 | =over 4 |
| 233 | |
| 234 | =item * |
| 235 | |
| 236 | XXX Describe change here |
| 237 | |
| 238 | =back |
| 239 | |
| 240 | =head1 Utility Changes |
| 241 | |
| 242 | XXX Changes to installed programs such as F<perlbug> and F<xsubpp> go |
| 243 | here. Most of these are built within the directories F<utils> and F<x2p>. |
| 244 | |
| 245 | [ List utility changes as a =head3 entry for each utility and =item |
| 246 | entries for each change |
| 247 | Use L<XXX> with program names to get proper documentation linking. ] |
| 248 | |
| 249 | =head3 L<XXX> |
| 250 | |
| 251 | =over 4 |
| 252 | |
| 253 | =item * |
| 254 | |
| 255 | XXX |
| 256 | |
| 257 | =back |
| 258 | |
| 259 | =head1 Configuration and Compilation |
| 260 | |
| 261 | XXX Changes to F<Configure>, F<installperl>, F<installman>, and analogous tools |
| 262 | go here. Any other changes to the Perl build process should be listed here. |
| 263 | However, any platform-specific changes should be listed in the |
| 264 | L</Platform Support> section, instead. |
| 265 | |
| 266 | [ List changes as a =item entry ]. |
| 267 | |
| 268 | =over 4 |
| 269 | |
| 270 | =item * |
| 271 | |
| 272 | Building perl with some Windows compilers used to fail due to a problem |
| 273 | with miniperl's C<glob> operator (which uses the C<perlglob> program) |
| 274 | deleting the PATH environment variable [perl #113798]. |
| 275 | |
| 276 | =back |
| 277 | |
| 278 | =head1 Testing |
| 279 | |
| 280 | XXX Any significant changes to the testing of a freshly built perl should be |
| 281 | listed here. Changes which create B<new> files in F<t/> go here as do any |
| 282 | large changes to the testing harness (e.g. when parallel testing was added). |
| 283 | Changes to existing files in F<t/> aren't worth summarising, although the bugs |
| 284 | that they represent may be covered elsewhere. |
| 285 | |
| 286 | [ List each test improvement as a =item entry ] |
| 287 | |
| 288 | =over 4 |
| 289 | |
| 290 | =item * |
| 291 | |
| 292 | XXX |
| 293 | |
| 294 | =back |
| 295 | |
| 296 | =head1 Platform Support |
| 297 | |
| 298 | XXX Any changes to platform support should be listed in the sections below. |
| 299 | |
| 300 | [ Within the sections, list each platform as a =item entry with specific |
| 301 | changes as paragraphs below it. ] |
| 302 | |
| 303 | =head2 New Platforms |
| 304 | |
| 305 | XXX List any platforms that this version of perl compiles on, that previous |
| 306 | versions did not. These will either be enabled by new files in the F<hints/> |
| 307 | directories, or new subdirectories and F<README> files at the top level of the |
| 308 | source tree. |
| 309 | |
| 310 | =over 4 |
| 311 | |
| 312 | =item XXX |
| 313 | |
| 314 | |
| 315 | =back |
| 316 | |
| 317 | =head2 Discontinued Platforms |
| 318 | |
| 319 | XXX List any platforms that this version of perl no longer compiles on. |
| 320 | |
| 321 | =over 4 |
| 322 | |
| 323 | =item XXX-some-platform |
| 324 | |
| 325 | XXX |
| 326 | |
| 327 | =back |
| 328 | |
| 329 | =head2 Platform-Specific Notes |
| 330 | |
| 331 | XXX List any changes for specific platforms. This could include configuration |
| 332 | and compilation changes or changes in portability/compatibility. However, |
| 333 | changes within modules for platforms should generally be listed in the |
| 334 | L</Modules and Pragmata> section. |
| 335 | |
| 336 | =over 4 |
| 337 | |
| 338 | =item VMS |
| 339 | |
| 340 | Quotes are now removed from the command verb (but not the parameters) for commands |
| 341 | spawned via C<system>, backticks, or a piped C<open>. Previously, quotes on the verb |
| 342 | were passed through to DCL, which would fail to recognize the command. Also, if the |
| 343 | verb is actually a path to an image or command procedure on an ODS-5 volume, quoting it |
| 344 | now allows the path to contain spaces. |
| 345 | |
| 346 | =item AIX |
| 347 | |
| 348 | Configure now always adds -qlanglvl=extc99 to the CC flags on AIX when |
| 349 | using xlC. This will make it easier to compile a number of XS-based modules |
| 350 | that assume C99 [perl #113778]. |
| 351 | |
| 352 | =back |
| 353 | |
| 354 | =head1 Internal Changes |
| 355 | |
| 356 | XXX Changes which affect the interface available to C<XS> code go here. |
| 357 | Other significant internal changes for future core maintainers should |
| 358 | be noted as well. |
| 359 | |
| 360 | [ List each change as a =item entry ] |
| 361 | |
| 362 | =over 4 |
| 363 | |
| 364 | =item * |
| 365 | |
| 366 | OP allocation for CVs now uses a slab allocator. This simplifies |
| 367 | memory management for OPs allocated to a CV, so cleaning up after a |
| 368 | compilation error is simpler and safer [perl #111462][perl #112312]. |
| 369 | |
| 370 | =back |
| 371 | |
| 372 | =head1 Selected Bug Fixes |
| 373 | |
| 374 | XXX Important bug fixes in the core language are summarised here. |
| 375 | Bug fixes in files in F<ext/> and F<lib/> are best summarised in |
| 376 | L</Modules and Pragmata>. |
| 377 | |
| 378 | [ List each fix as a =item entry ] |
| 379 | |
| 380 | =over 4 |
| 381 | |
| 382 | =item * |
| 383 | |
| 384 | A regression introduced in v5.14.0 has been fixed, in which some calls |
| 385 | to the C<re> module would clobber C<$_> [perl #113750]. |
| 386 | |
| 387 | =item * |
| 388 | |
| 389 | C<do FILE> now always either sets or clears C<$@>, even when the file can't be |
| 390 | read. This ensures that testing C<$@> first (as recommended by the |
| 391 | documentation) always returns the correct result. |
| 392 | |
| 393 | =item * |
| 394 | |
| 395 | The array iterator used for the C<each @array> construct is now correctly |
| 396 | reset when C<@array> is cleared (RT #75596). This happens for example when the |
| 397 | array is globally assigned to, as in C<@array = (...)>, but not when its |
| 398 | B<values> are assigned to. In terms of the XS API, it means that C<av_clear()> |
| 399 | will now reset the iterator. |
| 400 | |
| 401 | This mirrors the behaviour of the hash iterator when the hash is cleared. |
| 402 | |
| 403 | =item * |
| 404 | |
| 405 | C<< $class->can >>, C<< $class->isa >>, and C<< $class->DOES >> now return |
| 406 | correct results, regardless of whether that package referred to by C<$class> |
| 407 | exists [perl #47113]. |
| 408 | |
| 409 | =item * |
| 410 | |
| 411 | Arriving signals no longer clear C<$@> [perl #45173]. |
| 412 | |
| 413 | =item * |
| 414 | |
| 415 | Allow C<my ()> declarations with an empty variable list [perl #113554]. |
| 416 | |
| 417 | =item * |
| 418 | |
| 419 | During parsing, subs declared after errors no longer leave stubs |
| 420 | [perl #113712]. |
| 421 | |
| 422 | =item * |
| 423 | |
| 424 | Closures containing no string evals no longer hang on to their containing |
| 425 | subroutines, allowing variables closed over by outer subroutines to be |
| 426 | freed when the outer sub is freed, even if the inner sub still exists |
| 427 | [perl #89544]. |
| 428 | |
| 429 | =item * |
| 430 | |
| 431 | Duplication of in-memory filehandles by opening with a "<&=" or ">&=" mode |
| 432 | stopped working properly in 5.16.0. It was causing the new handle to |
| 433 | reference a different scalar variable. This has been fixed [perl #113764]. |
| 434 | |
| 435 | =item * |
| 436 | |
| 437 | C<qr//> expressions no longer crash with custom regular expression engines |
| 438 | that do not set C<offs> at regular expression compilation time |
| 439 | [perl #112962]. |
| 440 | |
| 441 | =item * |
| 442 | |
| 443 | C<delete local> no longer crashes with certain magical arrays and hashes |
| 444 | [perl #112966]. |
| 445 | |
| 446 | =item * |
| 447 | |
| 448 | C<local> on elements of certain magical arrays and hashes used not to |
| 449 | arrange to have the element deleted on scope exit, even if the element did |
| 450 | not exist before C<local>. |
| 451 | |
| 452 | =item * |
| 453 | |
| 454 | C<scalar(write)> no longer returns multiple items [perl #73690]. |
| 455 | |
| 456 | =item * |
| 457 | |
| 458 | String to floating point conversions no longer misparse certain strings under |
| 459 | C<use locale> [perl #109318]. |
| 460 | |
| 461 | =item * |
| 462 | |
| 463 | C<@INC> filters that die no longer leak memory [perl #92252]. |
| 464 | |
| 465 | =item * |
| 466 | |
| 467 | The implementations of overloaded operations are now called in the correct |
| 468 | context. This allows, among other things, being able to properly override |
| 469 | C<< <> >> [perl #47119]. |
| 470 | |
| 471 | =item * |
| 472 | |
| 473 | Specifying only the C<fallback> key when calling C<use overload> now behaves |
| 474 | properly [perl #113010]. |
| 475 | |
| 476 | =item * |
| 477 | |
| 478 | C<< sub foo { my $a = 0; while ($a) { ... } } >> and |
| 479 | C<< sub foo { while (0) { ... } } >> now return the same thing [perl #73618]. |
| 480 | |
| 481 | =item * |
| 482 | |
| 483 | Fixed the debugger C<l> and C<M> commands, and other debugger |
| 484 | functionality which was broken in 5.17.0 [perl #113918]. |
| 485 | |
| 486 | =item * |
| 487 | |
| 488 | String negation now behaves the same under C<use integer;> as it does |
| 489 | without [perl #113012]. |
| 490 | |
| 491 | =back |
| 492 | |
| 493 | =head1 Known Problems |
| 494 | |
| 495 | XXX Descriptions of platform agnostic bugs we know we can't fix go here. Any |
| 496 | tests that had to be C<TODO>ed for the release would be noted here. Unfixed |
| 497 | platform specific bugs also go here. |
| 498 | |
| 499 | [ List each fix as a =item entry ] |
| 500 | |
| 501 | =over 4 |
| 502 | |
| 503 | =item * |
| 504 | |
| 505 | XXX |
| 506 | |
| 507 | =back |
| 508 | |
| 509 | =head1 Obituary |
| 510 | |
| 511 | XXX If any significant core contributor has died, we've added a short obituary |
| 512 | here. |
| 513 | |
| 514 | =head1 Acknowledgements |
| 515 | |
| 516 | XXX Generate this with: |
| 517 | |
| 518 | perl Porting/acknowledgements.pl v5.17.1..HEAD |
| 519 | |
| 520 | =head1 Reporting Bugs |
| 521 | |
| 522 | If you find what you think is a bug, you might check the articles |
| 523 | recently posted to the comp.lang.perl.misc newsgroup and the perl |
| 524 | bug database at http://rt.perl.org/perlbug/ . There may also be |
| 525 | information at http://www.perl.org/ , the Perl Home Page. |
| 526 | |
| 527 | If you believe you have an unreported bug, please run the L<perlbug> |
| 528 | program included with your release. Be sure to trim your bug down |
| 529 | to a tiny but sufficient test case. Your bug report, along with the |
| 530 | output of C<perl -V>, will be sent off to perlbug@perl.org to be |
| 531 | analysed by the Perl porting team. |
| 532 | |
| 533 | If the bug you are reporting has security implications, which make it |
| 534 | inappropriate to send to a publicly archived mailing list, then please send |
| 535 | it to perl5-security-report@perl.org. This points to a closed subscription |
| 536 | unarchived mailing list, which includes |
| 537 | all the core committers, who will be able |
| 538 | to help assess the impact of issues, figure out a resolution, and help |
| 539 | co-ordinate the release of patches to mitigate or fix the problem across all |
| 540 | platforms on which Perl is supported. Please only use this address for |
| 541 | security issues in the Perl core, not for modules independently |
| 542 | distributed on CPAN. |
| 543 | |
| 544 | =head1 SEE ALSO |
| 545 | |
| 546 | The F<Changes> file for an explanation of how to view exhaustive details |
| 547 | on what changed. |
| 548 | |
| 549 | The F<INSTALL> file for how to build Perl. |
| 550 | |
| 551 | The F<README> file for general stuff. |
| 552 | |
| 553 | The F<Artistic> and F<Copying> files for copyright information. |
| 554 | |
| 555 | =cut |