4 284167a smueller Add C define to remove taint support from perl
5 ba593ad davem clone() wasn't cloning the whole stack
9 [ this is a template for a new perldelta file. Any text flagged as XXX needs
10 to be processed before release. ]
12 perldelta - what is new for perl v5.17.6
16 This document describes differences between the 5.17.5 release and the 5.17.6
19 If you are upgrading from an earlier release such as 5.17.4, first read
20 L<perl5175delta>, which describes differences between 5.17.4 and 5.17.5.
24 XXX Any important notices here
26 =head1 Core Enhancements
28 XXX New core language features go here. Summarize user-visible core language
29 enhancements. Particularly prominent performance optimisations could go
30 here, but most should go in the L</Performance Enhancements> section.
32 [ List each enhancement as a =head2 entry ]
34 =head2 Character name aliases may now include non-Latin1-range characters
36 It is possible to define your own names for characters for use in
37 C<\N{...}>, C<charnames::vianame()>, etc. These names can now be
38 comprised of characters from the whole Unicode range. This allows for
39 names to be in your native language, and not just English. Certain
40 restrictions apply to the characters that may be used (you can't define
41 a name that has punctuation in it, for example). See L<charnames/CUSTOM
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.
50 [ List each security issue as a =head2 entry ]
52 =head1 Incompatible Changes
54 XXX For a release on a stable branch, this section aspires to be:
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.
60 [ List each incompatible change as a =head2 entry ]
62 =head2 An unknown character name in C<\N{...}> is now a syntax error
64 Previously, it warned, and the Unicode REPLACEMENT CHARACTER was
65 substituted. Unicode now recommends that this situation be a syntax
66 error. Also, the previous behavior led to some confusing warnings and
67 behaviors, and since the REPLACEMENT CHARACTER has no use other than as
68 a stand-in for some unknown character, any code that has this problem is
71 =head2 Formerly deprecated characters in C<\N{}> character name aliases are now errors.
73 Since v5.12.0, it has been deprecated to use certain characters in
74 user-defined C<\N{...}> character names. These now cause a syntax
75 error. For example, it is now an error to begin a name with a digit,
78 my $undraftable = "\N{4F}"; # Syntax error!
80 or to have commas anywhere in the name. See L<charnames/CUSTOM ALIASES>
84 XXX Any deprecated features, syntax, modules etc. should be listed here. In
85 particular, deprecated modules should be listed here even if they are listed as
86 an updated module in the L</Modules and Pragmata> section.
88 [ List each deprecation as a =head2 entry ]
90 =head1 Performance Enhancements
92 XXX Changes which enhance performance without changing behaviour go here.
93 There may well be none in a stable release.
95 [ List each enhancement as a =item entry ]
101 Lists of lexical variable declarations (C<my($x, $y)>) are now optimised
102 down to a single op, and are hence faster than before.
106 =head1 Modules and Pragmata
108 XXX All changes to installed files in F<cpan/>, F<dist/>, F<ext/> and F<lib/>
109 go here. If Module::CoreList is updated, generate an initial draft of the
110 following sections using F<Porting/corelist-perldelta.pl>, which prints stub
111 entries to STDOUT. Results can be pasted in place of the '=head2' entries
112 below. A paragraph summary for important changes should then be added by hand.
113 In an ideal world, dual-life modules would have a F<Changes> file that could be
116 [ Within each section, list entries as a =item entry ]
118 =head2 New Modules and Pragmata
128 =head2 Updated Modules and Pragmata
134 L<Carp> has been upgraded from version 1.27 to 1.28.
136 Carp is no longer confused when C<caller> returns undef for a package that
141 L<CPAN> has been upgraded from version 1.98 to 1.99_51.
145 L<DynaLoader> has been upgraded from version 1.16 to 1.17.
149 L<Env> has been upgraded from version 1.03 to 1.04.
151 Its SPLICE implementation no longer misbehaves in list context.
155 L<Tie::Hash::NamedCapture> has been upgraded from version 0.08 to 0.09.
159 =head2 Removed Modules and Pragmata
171 XXX Changes to files in F<pod/> go here. Consider grouping entries by
172 file and be sure to link to the appropriate page, e.g. L<perlfunc>.
174 =head2 New Documentation
176 XXX Changes which create B<new> files in F<pod/> go here.
180 XXX Description of the purpose of the new file here
182 =head2 Changes to Existing Documentation
184 XXX Changes which significantly change existing files in F<pod/> go here.
185 However, any changes to F<pod/perldiag.pod> should go in the L</Diagnostics>
194 C<*foo{NAME}> and C<*foo{PACKAGE}>, which have existed since perl 5.005,
201 The following additions or changes have been made to diagnostic output,
202 including warnings and fatal error messages. For the complete list of
203 diagnostic messages, see L<perldiag>.
205 XXX New or changed warnings emitted by the core's C<C> code go here. Also
206 include any changes in L<perldiag> that reconcile it to the C<C> code.
208 =head2 New Diagnostics
210 XXX Newly added diagnostic messages go under here, separated into New Errors
219 XXX L<message|perldiag/"message">
229 XXX L<message|perldiag/"message">
233 =head2 Changes to Existing Diagnostics
235 XXX Changes (i.e. rewording) of diagnostic messages go here
241 XXX Describe change here
245 =head1 Utility Changes
247 XXX Changes to installed programs such as F<perlbug> and F<xsubpp> go here.
248 Most of these are built within the directories F<utils> and F<x2p>.
250 [ List utility changes as a =head3 entry for each utility and =item
251 entries for each change
252 Use L<XXX> with program names to get proper documentation linking. ]
264 =head1 Configuration and Compilation
266 XXX Changes to F<Configure>, F<installperl>, F<installman>, and analogous tools
267 go here. Any other changes to the Perl build process should be listed here.
268 However, any platform-specific changes should be listed in the
269 L</Platform Support> section, instead.
271 [ List changes as a =item entry ].
283 XXX Any significant changes to the testing of a freshly built perl should be
284 listed here. Changes which create B<new> files in F<t/> go here as do any
285 large changes to the testing harness (e.g. when parallel testing was added).
286 Changes to existing files in F<t/> aren't worth summarizing, although the bugs
287 that they represent may be covered elsewhere.
289 [ List each test improvement as a =item entry ]
299 =head1 Platform Support
301 XXX Any changes to platform support should be listed in the sections below.
303 [ Within the sections, list each platform as a =item entry with specific
304 changes as paragraphs below it. ]
308 XXX List any platforms that this version of perl compiles on, that previous
309 versions did not. These will either be enabled by new files in the F<hints/>
310 directories, or new subdirectories and F<README> files at the top level of the
315 =item XXX-some-platform
321 =head2 Discontinued Platforms
323 XXX List any platforms that this version of perl no longer compiles on.
327 =item XXX-some-platform
333 =head2 Platform-Specific Notes
335 XXX List any changes for specific platforms. This could include configuration
336 and compilation changes or changes in portability/compatibility. However,
337 changes within modules for platforms should generally be listed in the
338 L</Modules and Pragmata> section.
342 =item XXX-some-platform
348 =head1 Internal Changes
350 XXX Changes which affect the interface available to C<XS> code go here. Other
351 significant internal changes for future core maintainers should be noted as
354 [ List each change as a =item entry ]
360 The private Perl_croak_no_modify has had its context parameter removed. It is
361 now has a void prototype. Users of the public API croak_no_modify remain
366 Copy-on-write (shared hash key) scalars are no longer marked read-only.
367 C<SvREADONLY> returns false on such an SV, but C<SvIsCOW> still returns
372 =head1 Selected Bug Fixes
374 XXX Important bug fixes in the core language are summarized here. Bug fixes in
375 files in F<ext/> and F<lib/> are best summarized in L</Modules and Pragmata>.
377 [ List each fix as a =item entry ]
383 Uninitialized warnings mentioning hash elements would only mention the
384 element name if it was not in the first bucket of the hash, due to an
389 A regular expression optimizer bug could cause multiline "^" to behave
390 incorrectly in the presence of line breaks, such that
391 C<"/\n\n" =~ m#\A(?:^/$)#im> would not match [perl #115242].
395 Failed C<fork> in list context no longer currupts the stack.
396 C<@a = (1, 2, fork, 3)> used to gobble up the 2 and assign C<(1, undef, 3)>
397 if the C<fork> call failed.
401 Numerous memory leaks have been fixed, mostly involving tied variables that
402 die, regular expression character classes and code blocks, and syntax
407 Assigning a regular expression (C<${qr//}>) to a variable that happens to
408 hold a floating point number no longer causes assertion failures on
413 Assigning a regular expression to a scalar containing a number no longer
414 causes subsequent nummification to produce random numbers.
418 Assigning a regular expression to a magic variable no longer wipes away the
419 magic. This is a regression from 5.10.
423 Assigning a regular expression to a blessed scalar no longer results in
424 crashes. This is also a regression from 5.10.
428 Regular expression can now be assigned to tied hash and array elements with
429 flattening into strings.
433 Nummifying a regular expression no longer results in an uninitialized
438 Negative array indices no longer cause EXISTS methods of tied variables to
439 be ignored. This is a regression from 5.12.
443 Negative array indices no longer result in crashes on arrays tied to
448 C<$x = "(?{})"; /a++(?{})+$x/x> no longer erroneous produces an error (just
449 a warning, as expected). This was broken in 5.17.1.
453 C<$byte_overload .= $utf8> no longer results in doubly-encoded UTF8 if the
454 left-hand scalar happened to have produced a UTF8 string the last time
455 overloading was invoked.
459 C<goto &sub> now uses the current value of @_, instead of using the array
460 the subroutine was originally called with. This means
461 C<local @_ = (...); goto &sub> now works [perl #43077].
465 If a debugger is invoked recursively, it no longer stomps on its own
466 lexical variables. Formerly under recursion all calls would share the same
467 set of lexical variables [perl #115742].
471 C<*_{ARRAY}> returned from a subroutine no longer spontaneously
476 =head1 Known Problems
478 XXX Descriptions of platform agnostic bugs we know we can't fix go here. Any
479 tests that had to be C<TODO>ed for the release would be noted here. Unfixed
480 platform specific bugs also go here.
482 [ List each fix as a =item entry ]
494 XXX If any significant core contributor has died, we've added a short obituary
497 =head1 Acknowledgements
499 XXX Generate this with:
501 perl Porting/acknowledgements.pl v5.17.5..HEAD
503 =head1 Reporting Bugs
505 If you find what you think is a bug, you might check the articles recently
506 posted to the comp.lang.perl.misc newsgroup and the perl bug database at
507 http://rt.perl.org/perlbug/ . There may also be information at
508 http://www.perl.org/ , the Perl Home Page.
510 If you believe you have an unreported bug, please run the L<perlbug> program
511 included with your release. Be sure to trim your bug down to a tiny but
512 sufficient test case. Your bug report, along with the output of C<perl -V>,
513 will be sent off to perlbug@perl.org to be analysed by the Perl porting team.
515 If the bug you are reporting has security implications, which make it
516 inappropriate to send to a publicly archived mailing list, then please send it
517 to perl5-security-report@perl.org. This points to a closed subscription
518 unarchived mailing list, which includes all the core committers, who will be
519 able to help assess the impact of issues, figure out a resolution, and help
520 co-ordinate the release of patches to mitigate or fix the problem across all
521 platforms on which Perl is supported. Please only use this address for
522 security issues in the Perl core, not for modules independently distributed on
527 The F<Changes> file for an explanation of how to view exhaustive details on
530 The F<INSTALL> file for how to build Perl.
532 The F<README> file for general stuff.
534 The F<Artistic> and F<Copying> files for copyright information.