4 284167a smueller Add C define to remove taint support from perl
5 ba593ad davem clone() wasn't cloning the whole stack
6 7dc8663 demerphq Hash Function Change - Murmur hash and true per process...
10 [ this is a template for a new perldelta file. Any text flagged as XXX needs
11 to be processed before release. ]
13 perldelta - what is new for perl v5.17.6
17 This document describes differences between the 5.17.5 release and the 5.17.6
20 If you are upgrading from an earlier release such as 5.17.4, first read
21 L<perl5175delta>, which describes differences between 5.17.4 and 5.17.5.
25 XXX Any important notices here
27 =head1 Core Enhancements
29 XXX New core language features go here. Summarize user-visible core language
30 enhancements. Particularly prominent performance optimisations could go
31 here, but most should go in the L</Performance Enhancements> section.
33 [ List each enhancement as a =head2 entry ]
35 =head2 Character name aliases may now include non-Latin1-range characters
37 It is possible to define your own names for characters for use in
38 C<\N{...}>, C<charnames::vianame()>, etc. These names can now be
39 comprised of characters from the whole Unicode range. This allows for
40 names to be in your native language, and not just English. Certain
41 restrictions apply to the characters that may be used (you can't define
42 a name that has punctuation in it, for example). See L<charnames/CUSTOM
47 XXX Any security-related notices go here. In particular, any security
48 vulnerabilities closed should be noted here rather than in the
49 L</Selected Bug Fixes> section.
51 [ List each security issue as a =head2 entry ]
53 =head1 Incompatible Changes
55 XXX For a release on a stable branch, this section aspires to be:
57 There are no changes intentionally incompatible with 5.XXX.XXX
58 If any exist, they are bugs, and we request that you submit a
59 report. See L</Reporting Bugs> below.
61 [ List each incompatible change as a =head2 entry ]
63 =head2 An unknown character name in C<\N{...}> is now a syntax error
65 Previously, it warned, and the Unicode REPLACEMENT CHARACTER was
66 substituted. Unicode now recommends that this situation be a syntax
67 error. Also, the previous behavior led to some confusing warnings and
68 behaviors, and since the REPLACEMENT CHARACTER has no use other than as
69 a stand-in for some unknown character, any code that has this problem is
72 =head2 Formerly deprecated characters in C<\N{}> character name aliases are now errors.
74 Since v5.12.0, it has been deprecated to use certain characters in
75 user-defined C<\N{...}> character names. These now cause a syntax
76 error. For example, it is now an error to begin a name with a digit,
79 my $undraftable = "\N{4F}"; # Syntax error!
81 or to have commas anywhere in the name. See L<charnames/CUSTOM ALIASES>
85 XXX Any deprecated features, syntax, modules etc. should be listed here. In
86 particular, deprecated modules should be listed here even if they are listed as
87 an updated module in the L</Modules and Pragmata> section.
89 [ List each deprecation as a =head2 entry ]
91 =head1 Performance Enhancements
93 XXX Changes which enhance performance without changing behaviour go here.
94 There may well be none in a stable release.
96 [ List each enhancement as a =item entry ]
102 Lists of lexical variable declarations (C<my($x, $y)>) are now optimised
103 down to a single op, and are hence faster than before.
107 =head1 Modules and Pragmata
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
117 [ Within each section, list entries as a =item entry ]
119 =head2 New Modules and Pragmata
129 =head2 Updated Modules and Pragmata
135 L<Carp> has been upgraded from version 1.27 to 1.28.
137 Carp is no longer confused when C<caller> returns undef for a package that
142 L<CPAN> has been upgraded from version 1.98 to 1.99_51.
146 L<DynaLoader> has been upgraded from version 1.16 to 1.17.
150 L<Env> has been upgraded from version 1.03 to 1.04.
152 Its SPLICE implementation no longer misbehaves in list context.
156 L<Tie::Hash::NamedCapture> has been upgraded from version 0.08 to 0.09.
160 =head2 Removed Modules and Pragmata
172 XXX Changes to files in F<pod/> go here. Consider grouping entries by
173 file and be sure to link to the appropriate page, e.g. L<perlfunc>.
175 =head2 New Documentation
177 XXX Changes which create B<new> files in F<pod/> go here.
181 XXX Description of the purpose of the new file here
183 =head2 Changes to Existing Documentation
185 XXX Changes which significantly change existing files in F<pod/> go here.
186 However, any changes to F<pod/perldiag.pod> should go in the L</Diagnostics>
195 C<*foo{NAME}> and C<*foo{PACKAGE}>, which have existed since perl 5.005,
202 The following additions or changes have been made to diagnostic output,
203 including warnings and fatal error messages. For the complete list of
204 diagnostic messages, see L<perldiag>.
206 XXX New or changed warnings emitted by the core's C<C> code go here. Also
207 include any changes in L<perldiag> that reconcile it to the C<C> code.
209 =head2 New Diagnostics
211 XXX Newly added diagnostic messages go under here, separated into New Errors
220 XXX L<message|perldiag/"message">
230 XXX L<message|perldiag/"message">
234 =head2 Changes to Existing Diagnostics
236 XXX Changes (i.e. rewording) of diagnostic messages go here
242 XXX Describe change here
246 =head1 Utility Changes
248 XXX Changes to installed programs such as F<perlbug> and F<xsubpp> go here.
249 Most of these are built within the directories F<utils> and F<x2p>.
251 [ List utility changes as a =head3 entry for each utility and =item
252 entries for each change
253 Use L<XXX> with program names to get proper documentation linking. ]
265 =head1 Configuration and Compilation
267 XXX Changes to F<Configure>, F<installperl>, F<installman>, and analogous tools
268 go here. Any other changes to the Perl build process should be listed here.
269 However, any platform-specific changes should be listed in the
270 L</Platform Support> section, instead.
272 [ List changes as a =item entry ].
284 XXX Any significant changes to the testing of a freshly built perl should be
285 listed here. Changes which create B<new> files in F<t/> go here as do any
286 large changes to the testing harness (e.g. when parallel testing was added).
287 Changes to existing files in F<t/> aren't worth summarizing, although the bugs
288 that they represent may be covered elsewhere.
290 [ List each test improvement as a =item entry ]
300 =head1 Platform Support
302 XXX Any changes to platform support should be listed in the sections below.
304 [ Within the sections, list each platform as a =item entry with specific
305 changes as paragraphs below it. ]
309 XXX List any platforms that this version of perl compiles on, that previous
310 versions did not. These will either be enabled by new files in the F<hints/>
311 directories, or new subdirectories and F<README> files at the top level of the
316 =item XXX-some-platform
322 =head2 Discontinued Platforms
328 Support code relating to EPOC has been removed. EPOC was a family of
329 operating systems developed by Psion for mobile devices. It was the
330 predecessor of Symbian. The port was last updated in April 2002.
334 =head2 Platform-Specific Notes
336 XXX List any changes for specific platforms. This could include configuration
337 and compilation changes or changes in portability/compatibility. However,
338 changes within modules for platforms should generally be listed in the
339 L</Modules and Pragmata> section.
343 =item XXX-some-platform
349 =head1 Internal Changes
351 XXX Changes which affect the interface available to C<XS> code go here. Other
352 significant internal changes for future core maintainers should be noted as
355 [ List each change as a =item entry ]
361 The private Perl_croak_no_modify has had its context parameter removed. It is
362 now has a void prototype. Users of the public API croak_no_modify remain
367 Copy-on-write (shared hash key) scalars are no longer marked read-only.
368 C<SvREADONLY> returns false on such an SV, but C<SvIsCOW> still returns
373 A new op type, C<OP_PADRANGE> has been introduced. The perl peephole
374 optimiser will, where possible, substitute a single padrange op for a
375 pushmark followed by one or more pad ops, and possibly also skipping list
376 and nextstate ops. In addition, the op can carry out the tasks associated
377 with the RHS of a my(...) = @_ assignment, so those ops may be optimised
382 =head1 Selected Bug Fixes
384 XXX Important bug fixes in the core language are summarized here. Bug fixes in
385 files in F<ext/> and F<lib/> are best summarized in L</Modules and Pragmata>.
387 [ List each fix as a =item entry ]
393 Uninitialized warnings mentioning hash elements would only mention the
394 element name if it was not in the first bucket of the hash, due to an
399 A regular expression optimizer bug could cause multiline "^" to behave
400 incorrectly in the presence of line breaks, such that
401 C<"/\n\n" =~ m#\A(?:^/$)#im> would not match [perl #115242].
405 Failed C<fork> in list context no longer currupts the stack.
406 C<@a = (1, 2, fork, 3)> used to gobble up the 2 and assign C<(1, undef, 3)>
407 if the C<fork> call failed.
411 Numerous memory leaks have been fixed, mostly involving tied variables that
412 die, regular expression character classes and code blocks, and syntax
417 Assigning a regular expression (C<${qr//}>) to a variable that happens to
418 hold a floating point number no longer causes assertion failures on
423 Assigning a regular expression to a scalar containing a number no longer
424 causes subsequent nummification to produce random numbers.
428 Assigning a regular expression to a magic variable no longer wipes away the
429 magic. This is a regression from 5.10.
433 Assigning a regular expression to a blessed scalar no longer results in
434 crashes. This is also a regression from 5.10.
438 Regular expression can now be assigned to tied hash and array elements with
439 flattening into strings.
443 Nummifying a regular expression no longer results in an uninitialized
448 Negative array indices no longer cause EXISTS methods of tied variables to
449 be ignored. This is a regression from 5.12.
453 Negative array indices no longer result in crashes on arrays tied to
458 C<$x = "(?{})"; /a++(?{})+$x/x> no longer erroneous produces an error (just
459 a warning, as expected). This was broken in 5.17.1.
463 C<$byte_overload .= $utf8> no longer results in doubly-encoded UTF8 if the
464 left-hand scalar happened to have produced a UTF8 string the last time
465 overloading was invoked.
469 C<goto &sub> now uses the current value of @_, instead of using the array
470 the subroutine was originally called with. This means
471 C<local @_ = (...); goto &sub> now works [perl #43077].
475 If a debugger is invoked recursively, it no longer stomps on its own
476 lexical variables. Formerly under recursion all calls would share the same
477 set of lexical variables [perl #115742].
481 C<*_{ARRAY}> returned from a subroutine no longer spontaneously
486 =head1 Known Problems
488 XXX Descriptions of platform agnostic bugs we know we can't fix go here. Any
489 tests that had to be C<TODO>ed for the release would be noted here. Unfixed
490 platform specific bugs also go here.
492 [ List each fix as a =item entry ]
504 XXX If any significant core contributor has died, we've added a short obituary
507 =head1 Acknowledgements
509 XXX Generate this with:
511 perl Porting/acknowledgements.pl v5.17.5..HEAD
513 =head1 Reporting Bugs
515 If you find what you think is a bug, you might check the articles recently
516 posted to the comp.lang.perl.misc newsgroup and the perl bug database at
517 http://rt.perl.org/perlbug/ . There may also be information at
518 http://www.perl.org/ , the Perl Home Page.
520 If you believe you have an unreported bug, please run the L<perlbug> program
521 included with your release. Be sure to trim your bug down to a tiny but
522 sufficient test case. Your bug report, along with the output of C<perl -V>,
523 will be sent off to perlbug@perl.org to be analysed by the Perl porting team.
525 If the bug you are reporting has security implications, which make it
526 inappropriate to send to a publicly archived mailing list, then please send it
527 to perl5-security-report@perl.org. This points to a closed subscription
528 unarchived mailing list, which includes all the core committers, who will be
529 able to help assess the impact of issues, figure out a resolution, and help
530 co-ordinate the release of patches to mitigate or fix the problem across all
531 platforms on which Perl is supported. Please only use this address for
532 security issues in the Perl core, not for modules independently distributed on
537 The F<Changes> file for an explanation of how to view exhaustive details on
540 The F<INSTALL> file for how to build Perl.
542 The F<README> file for general stuff.
544 The F<Artistic> and F<Copying> files for copyright information.