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1 | =encoding utf8 |
2 | ||
3 | =head1 NAME | |
4 | ||
5 | perl5171delta - what is new for perl v5.17.1 | |
6 | ||
7 | =head1 DESCRIPTION | |
8 | ||
9 | This document describes differences between the 5.17.0 release and | |
10 | the 5.17.1 release. | |
11 | ||
12 | If you are upgrading from an earlier release such as 5.16.0, first read | |
13 | L<perl5170delta>, which describes differences between 5.16.0 and | |
14 | 5.17.0. | |
15 | ||
16 | =head1 Core Enhancements | |
17 | ||
18 | =head2 More CORE:: subs | |
19 | ||
20 | Several more built-in functions have been added as subroutines to the | |
21 | CORE:: namespace, namely, those non-overridable keywords that can be | |
22 | implemented without custom parsers: C<defined>, C<delete>, C<exists>, | |
23 | C<glob>, C<pos>, C<protoytpe>, C<scalar>, C<split>, C<study>, and C<undef>. | |
24 | ||
25 | As some of these have prototypes, C<prototype('CORE::...')> has been | |
26 | changed to not make a distinction between overridable and non-overridable | |
27 | keywords. This is to make C<prototype('CORE::pos')> consistent with | |
28 | C<prototype(&CORE::pos)>. | |
29 | ||
30 | =head1 Incompatible Changes | |
31 | ||
32 | =head2 C</(?{})/> and C</(??{})/> have been heavily reworked | |
33 | ||
34 | The implementation of this feature has been almost completely rewritten. | |
35 | Although its main intent is to fix bugs, some behaviors, especially | |
36 | related to the scope of lexical variables, will have changed. This is | |
37 | described more fully in the L</Selected Bug Fixes> section. | |
38 | ||
39 | =head2 C<\N{BELL}> now refers to U+1F514 instead of U+0007 | |
40 | ||
41 | Unicode 6.0 reused the name "BELL" for a different code point than it | |
42 | traditionally had meant. Since Perl v5.14, use of this name still | |
43 | referred to U+0007, but would raise a deprecation warning. Now, "BELL" | |
44 | refers to U+1F514, and the name for U+0007 is "ALERT". All the | |
45 | functions in L<charnames> have been correspondingly updated. | |
46 | ||
47 | =head2 Alphanumeric operators must now be separated from the closing | |
48 | delimiter of regular expressions | |
49 | ||
50 | You may no longer write something like: | |
51 | ||
52 | m/a/and 1 | |
53 | ||
54 | Instead you must write | |
55 | ||
56 | m/a/ and 1 | |
57 | ||
58 | with whitespace separating the operator from the closing delimiter of | |
59 | the regular expression. Not having whitespace has resulted in a | |
60 | deprecation warning since Perl v5.14.0. | |
61 | ||
62 | =head2 C<require> dies for unreadable files | |
63 | ||
64 | When C<require> encounters an unreadable file, it now dies. It used to | |
65 | ignore the file and continue searching the directories in @INC | |
66 | [perl #113422]. | |
67 | ||
68 | =head2 Upgrade to the Unicode 6.2 beta | |
69 | ||
70 | Unicode 6.2 is proposing some changes that may very well break some CPAN | |
71 | modules. The timing of this nicely coincides with Perl's being early in the | |
72 | release cycle. This commit takes the current beta 6.2, adds the proposed | |
73 | changes that aren't yet in it, and subtracts the changes that would affect \X | |
74 | processing, as those turn out to have errors, and may have to be rethought. | |
75 | Unicode has been notified of these problems. | |
76 | ||
77 | This will allow us to gather data as to whether or not the proposed changes | |
78 | cause us problems. These will be presented to Unicode to aid in their final | |
79 | decision as to whether or not to go forward with the changes. | |
80 | ||
81 | These changes will be replaced by the final version of Unicode 6.2 before | |
82 | 5.18.0 is released. | |
83 | ||
84 | =head1 Performance Enhancements | |
85 | ||
86 | =over 4 | |
87 | ||
88 | =item * | |
89 | ||
90 | The C<x> repetition operator is now folded to a single constant at compile | |
91 | time if called in scalar context with constant operands and no parentheses | |
92 | around the left operand. | |
93 | ||
94 | =back | |
95 | ||
96 | =head1 Modules and Pragmata | |
97 | ||
98 | =head2 Updated Modules and Pragmata | |
99 | ||
100 | =over 4 | |
101 | ||
102 | =item * | |
103 | ||
104 | L<Archive::Extract> has been upgraded from version 0.58 to 0.60. | |
105 | ||
106 | Work around an edge case on Linux with Busybox's unzip. | |
107 | ||
108 | =item * | |
109 | ||
110 | L<Archive::Tar> has been upgraded from version 1.82 to 1.88. | |
111 | ||
112 | ptar now supports the -T option as well as dashless options | |
113 | [rt.cpan.org #75473], [rt.cpan.org #75475]. | |
114 | ||
115 | Auto-encode filenames marked as UTF-8 [rt.cpan.org #75474]. | |
116 | ||
117 | Don't use C<tell> on L<IO::Zlib> handles [rt.cpan.org #64339]. | |
118 | ||
119 | Don't try to C<chown> on symlinks. | |
120 | ||
121 | =item * | |
122 | ||
123 | L<attributes> has been upgraded from version 0.19 to 0.20. | |
124 | ||
125 | =item * | |
126 | ||
127 | L<autodie> has been upgraded from version 2.10 to 2.11. | |
128 | ||
129 | =item * | |
130 | ||
131 | L<B> has been upgraded from version 1.35 to 1.36. | |
132 | ||
133 | C<B::COP::stashlen> has been replaced with C<B::COP::stashoff>. | |
134 | ||
135 | C<B::COP::stashpv> now supports UTF-8 package names and embedded NULs. | |
136 | ||
137 | =item * | |
138 | ||
139 | L<B::Deparse> has been upgraded from version 1.14 to 1.15. | |
140 | ||
141 | Avoid warning when run under C<perl -w>. | |
142 | ||
143 | =item * | |
144 | ||
145 | L<Class::Struct> has been upgraded from version 0.63 to 0.64. | |
146 | ||
147 | The constructor now respects overridden accessor methods [perl #29230]. | |
148 | ||
149 | =item * | |
150 | ||
151 | L<Compress::Raw::Bzip2> has been upgraded from version 2.048 to 2.052. | |
152 | ||
153 | =item * | |
154 | ||
155 | L<Compress::Raw::Zlib> has been upgraded from version 2.048 to 2.054. | |
156 | ||
157 | Upgrade bundled zlib to version 1.2.7. | |
158 | ||
159 | Fix build failures on Irix, Solaris, and Win32, and also when building as C++ | |
160 | [rt.cpan.org #69985], [rt.cpan.org #77030], [rt.cpan.org #75222]. | |
161 | ||
162 | =item * | |
163 | ||
164 | L<CPAN::Meta> has been upgraded from version 2.120630 to 2.120921. | |
165 | ||
166 | =item * | |
167 | ||
168 | L<CPAN::Meta::Requirements> has been upgraded from version 2.120630 to 2.122. | |
169 | ||
170 | Treat undef requirements to C<from_string_hash> as 0 (with a warning). | |
171 | ||
172 | Added C<requirements_for_module> method. | |
173 | ||
174 | =item * | |
175 | ||
176 | L<CPAN::Meta::YAML> has been upgraded from version 0.007 to 0.008. | |
177 | ||
178 | =item * | |
179 | ||
180 | L<CPANPLUS> has been upgraded from version 0.9121 to 0.9130. | |
181 | ||
182 | Allow adding F<blib/script> to PATH. | |
183 | ||
184 | Save the history between invocations of the shell. | |
185 | ||
186 | Handle multiple C<makemakerargs> and C<makeflags> arguments better. | |
187 | ||
188 | Use C<File::HomeDir> when available, and provide C<PERL5_CPANPLUS_HOME> to | |
189 | override the autodetection. | |
190 | ||
191 | Always re-fetch F<CHECKSUMS> if C<fetchdir> is set. | |
192 | ||
193 | =item * | |
194 | ||
195 | L<Digest::MD5> has been upgraded from version 2.51 to 2.52. | |
196 | ||
197 | Fix C<Digest::Perl::MD5> OO fallback [rt.cpan.org #66634]. | |
198 | ||
199 | =item * | |
200 | ||
201 | L<DynaLoader> has been upgraded from version 1.14 to 1.15. | |
202 | ||
203 | This is due to a minor code change in the XS for the VMS implementation. | |
204 | ||
205 | =item * | |
206 | ||
207 | L<ExtUtils::CBuilder> has been upgraded from version 0.280206 to 0.280208. | |
208 | ||
209 | Manifest files are now correctly embedded for those versions of VC++ which | |
210 | make use of them. [perl #111782, #111798]. | |
211 | ||
212 | =item * | |
213 | ||
214 | L<File::DosGlob> has been upgraded from version 1.07 to 1.08. | |
215 | ||
216 | =item * | |
217 | ||
218 | L<File::Fetch> has been upgraded from version 0.32 to 0.34. | |
219 | ||
220 | =item * | |
221 | ||
222 | L<File::Spec::Unix> has been upgraded from version 3.39_02 to 3.39_03. | |
223 | ||
224 | C<abs2rel> could produce incorrect results when given two relative paths or | |
225 | the root directory twice [perl #111510]. | |
226 | ||
227 | =item * | |
228 | ||
229 | L<Filter::Util::Call> has been upgraded from version 1.40 to 1.45. | |
230 | ||
231 | =item * | |
232 | ||
233 | L<HTTP::Tiny> has been upgraded from version 0.017 to 0.022. | |
234 | ||
235 | Add SSL verification features [github #6], [github #9]. | |
236 | ||
237 | Include the final URL in the response hashref. | |
238 | ||
239 | Add C<local_address> option. | |
240 | ||
241 | =item * | |
242 | ||
243 | L<IO> has been upgraded from version 1.25_06 to 1.25_07. | |
244 | ||
245 | C<sync()> can now be called on read-only file handles [perl #64772]. | |
246 | ||
247 | =item * | |
248 | ||
249 | L<IPC::Cmd> has been upgraded from version 0.76 to 0.78. | |
250 | ||
251 | Use C<POSIX::_exit> instead of C<exit> in C<run_forked> [rt.cpan.org #76901]. | |
252 | ||
253 | =item * | |
254 | ||
255 | L<Memoize> has been upgraded from version 1.02 to 1.03. | |
256 | ||
257 | Fix the C<MERGE> cache option. | |
258 | ||
259 | =item * | |
260 | ||
261 | L<Module::Build> has been upgraded from version 0.39_01 to 0.40. | |
262 | ||
263 | Fixed bug where modules without C<$VERSION> might have a version of '0' listed | |
264 | in 'provides' metadata, which will be rejected by PAUSE. | |
265 | ||
266 | Fixed bug in PodParser to allow numerals in module names. | |
267 | ||
268 | Fixed bug where giving arguments twice led to them becoming arrays, resulting | |
269 | in install paths like F<ARRAY(0xdeadbeef)/lib/Foo.pm>. | |
270 | ||
271 | =item * | |
272 | ||
273 | L<Module::CoreList> has been upgraded from version 2.67 to 2.68. | |
274 | ||
275 | =item * | |
276 | ||
277 | L<Module::Load::Conditional> has been upgraded from version 0.46 to 0.50. | |
278 | ||
279 | Fix use of C<requires> on perls installed to a path with spaces. | |
280 | ||
281 | =item * | |
282 | ||
283 | L<Object::Accessor> has been upgraded from version 0.42 to 0.44. | |
284 | ||
285 | =item * | |
286 | ||
287 | L<Params::Check> has been upgraded from version 0.32 to 0.36. | |
288 | ||
289 | =item * | |
290 | ||
291 | L<Parse::CPAN::Meta> has been upgraded from version 1.4402 to 1.4404. | |
292 | ||
293 | =item * | |
294 | ||
295 | L<PerlIO::mmap> has been upgraded from version 0.010 to 0.011. | |
296 | ||
297 | =item * | |
298 | ||
299 | L<PerlIO::via::QuotedPrint> has been upgraded from version 0.06 to 0.07. | |
300 | ||
301 | =item * | |
302 | ||
303 | L<Pod::Html> has been upgraded from version 1.15_02 to 1.16. | |
304 | ||
305 | The option C<--libpods> has been reinstated. It is deprecated, and its use | |
306 | does nothing other than issue a warning that it is no longer supported. | |
307 | ||
308 | Since the HTML files generated by pod2html claim to have a UTF-8 charset, | |
309 | actually write the files out using UTF-8 [perl #111446]. | |
310 | ||
311 | =item * | |
312 | ||
313 | L<POSIX> has been upgraded from version 1.30 to 1.31. | |
314 | ||
315 | =item * | |
316 | ||
317 | L<re> has been upgraded from version 0.19 to 0.20. | |
318 | ||
319 | See note about C<op_comp> in the L</Internal Changes> section below. | |
320 | ||
321 | =item * | |
322 | ||
323 | L<Safe> has been upgraded from version 2.31_01 to 2.33_01. | |
324 | ||
325 | Fix interactions with C<Devel::Cover>. | |
326 | ||
327 | Don't eval code under C<no strict>. | |
328 | ||
329 | =item * | |
330 | ||
331 | L<Scalar::Util> has been upgraded from version 1.23 to version 1.25. | |
332 | ||
333 | Fix an overloading issue with C<sum>. | |
334 | ||
335 | C<first> and C<reduce> now check the callback first (so C<&first(1)> is | |
336 | disallowed). | |
337 | ||
338 | Fix C<tainted> on magical values [rt.cpan.org #55763]. | |
339 | ||
340 | Fix C<sum> on previously magical values [rt.cpan.org #61118]. | |
341 | ||
342 | Fix reading past the end of a fixed buffer [rt.cpan.org #72700]. | |
343 | ||
344 | =item * | |
345 | ||
346 | L<Search::Dict> has been upgraded from version 1.04 to 1.07. | |
347 | ||
348 | No longer require C<stat> on filehandles. | |
349 | ||
350 | Use C<fc> for casefolding. | |
351 | ||
352 | =item * | |
353 | ||
354 | L<Storable> has been upgraded from version 2.35 to 2.36. | |
355 | ||
356 | =item * | |
357 | ||
358 | L<Term::ANSIColor> has been upgraded from version 3.01 to 3.02. | |
359 | ||
360 | Add support for italics. | |
361 | ||
362 | Improve error handling. | |
363 | ||
364 | =item * | |
365 | ||
366 | L<Test::Harness> has been upgraded from version 3.23 to 3.25. | |
367 | ||
368 | Fix glob semantics on Win32 [rt.cpan.org #49732]. | |
369 | ||
370 | Don't use C<Win32::GetShortPathName> when calling perl [rt.cpan.org #47890]. | |
371 | ||
372 | Ignore -T when reading shebang [rt.cpan.org #64404]. | |
373 | ||
374 | Handle the case where we don't know the wait status of the test more | |
375 | gracefully. | |
376 | ||
377 | Make the test summary 'ok' line overridable so that it can be changed to a | |
378 | plugin to make the output of prove idempotent. | |
379 | ||
380 | Don't run world-writable files. | |
381 | ||
382 | =item * | |
383 | ||
384 | L<Unicode::UCD> has been upgraded from version 0.43 to 0.44. | |
385 | ||
386 | This adds a function L<all_casefolds()|Unicode::UCD/all_casefolds()> | |
387 | that returns all the casefolds. | |
388 | ||
389 | =back | |
390 | ||
391 | =head1 Documentation | |
392 | ||
393 | =head2 Changes to Existing Documentation | |
394 | ||
395 | =head3 L<perlfaq> | |
396 | ||
397 | =over 4 | |
398 | ||
399 | =item * | |
400 | ||
401 | L<perlfaq> has been synchronized with version 5.0150040 from CPAN. | |
402 | ||
403 | =back | |
404 | ||
405 | =head3 L<perlcheat> | |
406 | ||
407 | =over 4 | |
408 | ||
409 | =item * | |
410 | ||
411 | L<perlcheat> has been reorganized, and a few new sections were added. | |
412 | ||
413 | =back | |
414 | ||
415 | =head1 Diagnostics | |
416 | ||
417 | =head2 Removals of Diagnostics | |
418 | ||
419 | =over 4 | |
420 | ||
421 | =item * | |
422 | ||
423 | The "Runaway prototype" warning that occurs in bizarre cases has been | |
424 | removed as being unhelpful and inconsistent. | |
425 | ||
426 | =item * | |
427 | ||
428 | The "Not a format reference" error has been removed, as the only case in | |
429 | which it could be triggered was a bug. | |
430 | ||
431 | =item * | |
432 | ||
433 | The "Unable to create sub named %s" error has been removed for the same | |
434 | reason. | |
435 | ||
436 | =back | |
437 | ||
438 | =head1 Platform Support | |
439 | ||
440 | =head2 Platform-Specific Notes | |
441 | ||
442 | =over 4 | |
443 | ||
444 | =item Win32 | |
445 | ||
446 | C<link> on Win32 now attempts to set C<$!> to more appropriate values | |
447 | based on the Win32 API error code. [perl #112272] | |
448 | ||
449 | Perl no longer mangles the environment block, e.g. when launching a new | |
450 | sub-process, when the environment contains non-ASCII characters. Known | |
451 | problems still remain, however, when the environment contains characters | |
452 | outside of the current ANSI codepage (e.g. see the item about Unicode in | |
453 | C<%ENV> in L<http://perl5.git.perl.org/perl.git/blob/HEAD:/Porting/todo.pod>). | |
454 | [perl #113536] | |
455 | ||
456 | =item VMS | |
457 | ||
458 | All C header files from the top-level directory of the distribution are now | |
459 | installed on VMS, providing consistency with a long-standing practice on other | |
460 | platforms. Previously only a subset were installed, which broke non-core | |
461 | extension builds for extensions that depended on the missing include files. | |
462 | ||
463 | =back | |
464 | ||
465 | =head1 Internal Changes | |
466 | ||
467 | =over 4 | |
468 | ||
469 | =item * | |
470 | ||
471 | The C<study> function was made a no-op in 5.16. It was simply disabled via | |
472 | a C<return> statement; the code was left in place. Now the code supporting | |
473 | what C<study> used to do has been removed. | |
474 | ||
475 | =item * | |
476 | ||
477 | Under threaded perls, there is no longer a separate PV allocated for every | |
478 | COP to store its package name (C<< cop->stashpv >>). Instead, there is an | |
479 | offset (C<< cop->stashoff >>) into the new C<PL_stashpad> array, which | |
480 | holds stash pointers. | |
481 | ||
482 | =item * | |
483 | ||
484 | In the pluggable regex API, the C<regexp_engine> struct has acquired a new | |
485 | field C<op_comp>, which is currently just for perl's internal use, and | |
486 | should be initialised to NULL by other regex plugin modules. | |
487 | ||
488 | =item * | |
489 | ||
490 | A new function C<alloccoptash> has been added to the API, but is considered | |
491 | experimental. See L<perlapi>. | |
492 | ||
493 | =back | |
494 | ||
495 | =head1 Selected Bug Fixes | |
496 | ||
497 | =over 4 | |
498 | ||
499 | =item * | |
500 | ||
501 | The implementation of code blocks in regular expressions, such as C<(?{})> | |
502 | and C<(??{})>, has been heavily reworked to eliminate a whole slew of bugs. | |
503 | The main user-visible changes are: | |
504 | ||
505 | =over 4 | |
506 | ||
507 | =item * | |
508 | ||
509 | Code blocks within patterns are now parsed in the same pass as the | |
510 | surrounding code; in particular it is no longer necessary to have balanced | |
511 | braces: this now works: | |
512 | ||
513 | /(?{ $x='{' })/ | |
514 | ||
515 | This means that this error message is longer generated: | |
516 | ||
517 | Sequence (?{...}) not terminated or not {}-balanced in regex | |
518 | ||
519 | but a new error may be seen: | |
520 | ||
521 | Sequence (?{...}) not terminated with ')' | |
522 | ||
523 | In addition, literal code blocks within run-time patterns are only | |
524 | compiled once, at perl compile-time: | |
525 | ||
526 | for my $p (...) { | |
527 | # this 'FOO' block of code is compiled once, | |
528 | # at the same time as the surrounding 'for' loop | |
529 | /$p{(?{FOO;})/; | |
530 | } | |
531 | ||
532 | =item * | |
533 | ||
534 | Lexical variables are now sane as regards scope, recursion and closure | |
535 | behavior. In particular, C</A(?{B})C/> behaves (from a closure viewpoint) | |
536 | exactly like C</A/ && do { B } && /C/>, while C<qr/A(?{B})C/> is like | |
537 | C<sub {/A/ && do { B } && /C/}>. So this code now works how you might | |
538 | expect, creating three regexes that match 0, 1, and 2: | |
539 | ||
540 | for my $i (0..2) { | |
541 | push @r, qr/^(??{$i})$/; | |
542 | } | |
543 | "1" =~ $r[1]; # matches | |
544 | ||
545 | =item * | |
546 | ||
547 | The C<use re 'eval'> pragma is now only required for code blocks defined | |
548 | at runtime; in particular in the following, the text of the C<$r> pattern is | |
549 | still interpolated into the new pattern and recompiled, but the individual | |
550 | compiled code-blocks within C<$r> are reused rather than being recompiled, | |
551 | and C<use re 'eval'> isn't needed any more: | |
552 | ||
553 | my $r = qr/abc(?{....})def/; | |
554 | /xyz$r/; | |
555 | ||
556 | =item * | |
557 | ||
558 | Flow control operators no longer crash. Each code block runs in a new | |
f73ab5ab FC |
559 | dynamic scope, so C<next> etc. will not see |
560 | any enclosing loops. C<return> returns a value | |
e96e0834 JL |
561 | from the code block, not from any enclosing subroutine. |
562 | ||
563 | =item * | |
564 | ||
565 | Perl normally caches the compilation of run-time patterns, and doesn't | |
566 | recompile if the pattern hasn't changed, but this is now disabled if | |
567 | required for the correct behavior of closures. For example: | |
568 | ||
569 | my $code = '(??{$x})'; | |
570 | for my $x (1..3) { | |
571 | # recompile to see fresh value of $x each time | |
572 | $x =~ /$code/; | |
573 | } | |
574 | ||
575 | ||
576 | =item * | |
577 | ||
578 | The C</msix> and C<(?msix)> etc. flags are now propagated into the return | |
579 | value from C<(??{})>; this now works: | |
580 | ||
581 | "AB" =~ /a(??{'b'})/i; | |
582 | ||
583 | =item * | |
584 | ||
585 | Warnings and errors will appear to come from the surrounding code (or for | |
586 | run-time code blocks, from an eval) rather than from an C<re_eval>: | |
587 | ||
588 | use re 'eval'; $c = '(?{ warn "foo" })'; /$c/; | |
589 | /(?{ warn "foo" })/; | |
590 | ||
591 | formerly gave: | |
592 | ||
593 | foo at (re_eval 1) line 1. | |
594 | foo at (re_eval 2) line 1. | |
595 | ||
596 | and now gives: | |
597 | ||
598 | foo at (eval 1) line 1. | |
599 | foo at /some/prog line 2. | |
600 | ||
601 | =back | |
602 | ||
603 | =item * | |
604 | ||
605 | Perl now works as well as can be expected on all releases of Unicode so | |
606 | far. In v5.16, it worked on Unicodes 6.0 and 6.1, but there were | |
607 | various bugs for earlier releases; the older the release the more | |
608 | problems. | |
609 | ||
610 | =item * | |
611 | ||
612 | C<vec> no longer produces "uninitialized" warnings in lvalue context | |
613 | [perl #9423]. | |
614 | ||
615 | =item * | |
616 | ||
617 | An optimization involving fixed strings in regular expressions could cause | |
618 | a severe performance penalty in edge cases. This has been fixed | |
619 | [perl #76546]. | |
620 | ||
621 | =item * | |
622 | ||
623 | In certain cases, including empty subpatterns within a regular expression (such | |
624 | as C<(?:)> or C<(?:|)>) could disable some optimizations. This has been fixed. | |
625 | ||
626 | =item * | |
627 | ||
628 | The "Can't find an opnumber" message that C<prototype> produces when passed | |
629 | a string like "CORE::nonexistent_keyword" now passes UTF-8 and embedded | |
630 | NULs through unchanged [perl #97478]. | |
631 | ||
632 | =item * | |
633 | ||
634 | C<prototype> now treats magical variables like C<$1> the same way as | |
635 | non-magical variables when checking for the CORE:: prefix, instead of | |
636 | treating them as subroutine names. | |
637 | ||
638 | =item * | |
639 | ||
640 | Under threaded perls, a runtime code block in a regular expression could | |
641 | corrupt the package name stored in the op tree, resulting in bad reads | |
642 | in C<caller>, and possibly crashes [perl #113060]. | |
643 | ||
644 | =item * | |
645 | ||
646 | Referencing a closure prototype (C<\&{$_[1]}> in an attribute handler for a | |
647 | closure) no longer results in a copy of the subroutine (or assertion | |
648 | failures on debugging builds). | |
649 | ||
650 | =item * | |
651 | ||
652 | C<eval '__PACKAGE__'> now returns the right answer on threaded builds if | |
653 | the current package has been assigned over (as in | |
654 | C<*ThisPackage:: = *ThatPackage::>) [perl #78742]. | |
655 | ||
656 | =item * | |
657 | ||
658 | If a package is deleted by code that it calls, it is possible for C<caller> | |
659 | to see a stack frame belonging to that deleted package. C<caller> could | |
660 | crash if the stash's memory address was reused for a scalar and a | |
661 | substitution was performed on the same scalar [perl #113486]. | |
662 | ||
663 | =item * | |
664 | ||
665 | C<UNIVERSAL::can> no longer treats its first argument differently | |
666 | depending on whether it is a string or number internally. | |
667 | ||
668 | =item * | |
669 | ||
670 | C<open> with C<< <& >> for the mode checks to see whether the third argument is | |
671 | a number, in determining whether to treat it as a file descriptor or a handle | |
672 | name. Magical variables like C<$1> were always failing the numeric check and | |
673 | being treated as handle names. | |
674 | ||
675 | =item * | |
676 | ||
677 | C<warn>'s handling of magical variables (C<$1>, ties) has undergone several | |
678 | fixes. C<FETCH> is only called once now on a tied argument or a tied C<$@> | |
679 | [perl #97480]. Tied variables returning objects that stringify as "" are | |
680 | no longer ignored. A tied C<$@> that happened to return a reference the | |
00a0fadd | 681 | I<previous> time it was used is no longer ignored. |
e96e0834 JL |
682 | |
683 | =item * | |
684 | ||
685 | C<warn ""> now treats C<$@> with a number in it the same way, regardless of | |
686 | whether it happened via C<$@=3> or C<$@="3">. It used to ignore the | |
687 | former. Now it appends "\t...caught", as it has always done with | |
688 | C<$@="3">. | |
689 | ||
690 | =item * | |
691 | ||
692 | Numeric operators on magical variables (e.g., S<C<$1 + 1>>) used to use | |
693 | floating point operations even where integer operations were more appropriate, | |
694 | resulting in loss of accuracy on 64-bit platforms [perl #109542]. | |
695 | ||
696 | =item * | |
697 | ||
698 | Unary negation no longer treats a string as a number if the string happened | |
699 | to be used as a number at some point. So, if C<$x> contains the string "dogs", | |
700 | C<-$x> returns "-dogs" even if C<$y=0+$x> has happened at some point. | |
701 | ||
702 | =item * | |
703 | ||
704 | In Perl 5.14, C<-'-10'> was fixed to return "10", not "+10". But magical | |
705 | variables (C<$1>, ties) were not fixed till now [perl #57706]. | |
706 | ||
707 | =item * | |
708 | ||
709 | Unary negation now treats strings consistently, regardless of the internal | |
710 | C<UTF8> flag. | |
711 | ||
712 | =item * | |
713 | ||
714 | A regression introduced in Perl v5.16.0 involving | |
715 | C<tr/I<SEARCHLIST>/I<REPLACEMENTLIST>/> has been fixed. Only the first | |
716 | instance is supposed to be meaningful if a character appears more than | |
717 | once in C<I<SEARCHLIST>>. Under some circumstances, the final instance | |
718 | was overriding all earlier ones. [perl #113584] | |
719 | ||
720 | =item * | |
721 | ||
722 | Regular expressions like C<qr/\87/> previously silently inserted a NUL | |
723 | character, thus matching as if it had been written C<qr/\00087/>. Now it | |
724 | matches as if it had been written as C<qr/87/>, with a message that the | |
725 | sequence C<"\8"> is unrecognized. | |
726 | ||
727 | =item * | |
728 | ||
729 | C<__SUB__> now works in special blocks (C<BEGIN>, C<END>, etc.). | |
730 | ||
731 | =item * | |
732 | ||
733 | Thread creation on Windows could theoretically result in a crash if done | |
734 | inside a C<BEGIN> block. It still does not work properly, but it no longer | |
735 | crashes [perl #111610]. | |
736 | ||
737 | =item * | |
738 | ||
739 | C<\&{''}> (with the empty string) now autovivifies a stub like any other | |
740 | sub name, and no longer produces the "Unable to create sub" error | |
741 | [perl #94476]. | |
742 | ||
743 | =back | |
744 | ||
745 | =head1 Known Problems | |
746 | ||
747 | =over 4 | |
748 | ||
749 | =item * | |
750 | ||
751 | On VMS, L<Module::Build> still fails its test suite. | |
752 | ||
753 | =item * | |
754 | ||
755 | On Win32, several tests fail intermittently, and may hang unless STDERR is | |
756 | redirected. | |
757 | ||
758 | =back | |
759 | ||
760 | =head1 Acknowledgements | |
761 | ||
762 | Perl 5.17.1 represents approximately 4 weeks of development since Perl 5.17.0 | |
763 | and contains approximately 37,000 lines of changes across 710 files from 35 | |
764 | authors. | |
765 | ||
766 | Perl continues to flourish into its third decade thanks to a vibrant community | |
767 | of users and developers. The following people are known to have contributed the | |
768 | improvements that became Perl 5.17.1: | |
769 | ||
770 | ?, Andy Dougherty, Aristotle Pagaltzis, Breno G. de Oliveira, Brian Fraser, | |
771 | Chris 'BinGOs' Williams, Craig A. Berry, David Mitchell, Dominic Hargreaves, | |
772 | Evan Miller, Father Chrysostomos, Florian Ragwitz, H.Merijn Brand, Herbert | |
773 | Breunung, Hugo van der Sanden, Jesse Luehrs, Karl Williamson, Karthik | |
774 | Rajagopalan, Lukas Mai, Martin Hasch, Michael Schroeder, Nicholas Clark, Paul | |
775 | Johnson, Reini Urban, Renee Baecker, Rhesa Rozendaal, Ricardo Signes, Shlomi | |
776 | Fish, Steve Hay, Steve Peters, Sullivan Beck, Tony Cook, Volker Schatz, Yves | |
777 | Orton, Zefram. | |
778 | ||
779 | The list above is almost certainly incomplete as it is automatically generated | |
780 | from version control history. In particular, it does not include the names of | |
781 | the (very much appreciated) contributors who reported issues to the Perl bug | |
782 | tracker. | |
783 | ||
784 | Many of the changes included in this version originated in the CPAN modules | |
785 | included in Perl's core. We're grateful to the entire CPAN community for | |
786 | helping Perl to flourish. | |
787 | ||
788 | For a more complete list of all of Perl's historical contributors, please see | |
789 | the F<AUTHORS> file in the Perl source distribution. | |
790 | ||
791 | =head1 Reporting Bugs | |
792 | ||
793 | If you find what you think is a bug, you might check the articles | |
794 | recently posted to the comp.lang.perl.misc newsgroup and the perl | |
795 | bug database at http://rt.perl.org/perlbug/ . There may also be | |
796 | information at http://www.perl.org/ , the Perl Home Page. | |
797 | ||
798 | If you believe you have an unreported bug, please run the L<perlbug> | |
799 | program included with your release. Be sure to trim your bug down | |
800 | to a tiny but sufficient test case. Your bug report, along with the | |
801 | output of C<perl -V>, will be sent off to perlbug@perl.org to be | |
802 | analysed by the Perl porting team. | |
803 | ||
804 | If the bug you are reporting has security implications, which make it | |
805 | inappropriate to send to a publicly archived mailing list, then please send | |
806 | it to perl5-security-report@perl.org. This points to a closed subscription | |
807 | unarchived mailing list, which includes | |
808 | all the core committers, who will be able | |
809 | to help assess the impact of issues, figure out a resolution, and help | |
810 | co-ordinate the release of patches to mitigate or fix the problem across all | |
811 | platforms on which Perl is supported. Please only use this address for | |
812 | security issues in the Perl core, not for modules independently | |
813 | distributed on CPAN. | |
814 | ||
815 | =head1 SEE ALSO | |
816 | ||
817 | The F<Changes> file for an explanation of how to view exhaustive details | |
818 | on what changed. | |
819 | ||
820 | The F<INSTALL> file for how to build Perl. | |
821 | ||
822 | The F<README> file for general stuff. | |
823 | ||
824 | The F<Artistic> and F<Copying> files for copyright information. | |
825 | ||
826 | =cut |