5 df8c7dee Fix segfault in filehandle duplication
6 b66f3475 Fix PerlIO_get_cnt and friends
7 e94bb470 install useful Regexp::CARP_TRACE from Carp
8 88e3936f Fix processing of PERL_ENV_TABLES
9 9d32676e [perl #117265] fix various problems with safesyscalls
10 9c7618be regcomp.c: Use Perl_form() instead of buggy sprintf
11 531d75b0 [perl #89502]: Add support for Atari FreeMiNT platform
15 [ this is a template for a new perldelta file. Any text flagged as XXX needs
16 to be processed before release. ]
18 perldelta - what is new for perl v5.19.4
22 This document describes differences between the 5.19.3 release and the 5.19.4
25 If you are upgrading from an earlier release such as 5.19.2, first read
26 L<perl5193delta>, which describes differences between 5.19.2 and 5.19.3.
30 XXX Any important notices here
32 =head1 Core Enhancements
34 XXX New core language features go here. Summarize user-visible core language
35 enhancements. Particularly prominent performance optimisations could go
36 here, but most should go in the L</Performance Enhancements> section.
38 [ List each enhancement as a =head2 entry ]
40 =head2 C<rand> now uses a consistent random number generator
42 Previously perl would use a platform specific random number generator, varying
43 between the libc rand(), random() or drand48().
45 This meant that the quality of perl's random numbers would vary from platform
46 to platform, from the 15 bits of rand() on Windows to 48-bits on POSIX
47 platforms such as Linux with drand48().
49 Perl now uses its own internal drand48() implementation on all platforms. This
50 does not make perl's C<rand> cryptographically secure. [perl #115928]
52 =head2 Better 64-bit support
54 On 64-bit platforms, the internal array functions now use 64-bit offsets,
55 allowing Perl arrays to hold more than 2**31 elements, if you have the memory
58 The regular expression engine now supports strings longer than 2**31
59 characters. [perl #112790, #116907]
61 =head2 New slice syntax
63 The new C<%hash{...}> and C<@array[...]> syntax returns a list of key/value (or
68 Core Perl now mostly works on EBCDIC platforms. This is not true of
69 many modules, including some which are shipped with this release. If
70 you have resources to help continue this process, including test
71 machines, send email to L<mailto:perl-mvs@perl.org>.
73 As a result of this, certain C<XS> functions are now deprecated; see
78 XXX Any security-related notices go here. In particular, any security
79 vulnerabilities closed should be noted here rather than in the
80 L</Selected Bug Fixes> section.
82 [ List each security issue as a =head2 entry ]
84 =head1 Incompatible Changes
86 =head2 Locale decimal point character no longer leaks outside of
87 S<C<use locale>> scope (with the exception of $!)
89 This is actually a bug fix, but some code has come to rely on the bug being
90 present, so this change is listed here. The current locale that the program is
91 running under is not supposed to be visible to Perl code except within the
92 scope of a S<C<use locale>>. However, until now under certain circumstances,
93 the character used for a decimal point (often a comma) leaked outside the
96 This continues the work released in Perl 5.19.1. It turns out that that did
97 not catch all the leaks, including C<printf> and C<sprintf> not respecting
98 S<C<use locale>>. If your code is affected by this change, simply add a
101 Now, the only known place where S<C<use locale>> is not respected is in the
102 stringification of L<$!|perlvar/$!>.
104 =head2 Assignments of Windows sockets error codes to $! now prefer F<errno.h> values over WSAGetLastError() values
106 In previous versions of Perl, Windows sockets error codes as returned by
107 WSAGetLastError() were assigned to $!, and some constants such as ECONNABORTED,
108 not in F<errno.h> in VC++ (or the various Windows ports of gcc) were defined to
109 corresponding WSAE* values to allow $! to be tested against the E* constants
110 exported by L<Errno> and L<POSIX>.
112 This worked well until VC++ 2010 and later, which introduced new E* constants
113 with values E<gt> 100 into F<errno.h>, including some being (re)defined by perl
114 to WSAE* values. That caused problems when linking XS code against other
115 libraries which used the original definitions of F<errno.h> constants.
117 To avoid this incompatibility, perl now maps WSAE* error codes to E* values
118 where possible, and assigns those values to $!. The E* constants exported by
119 L<Errno> and L<POSIX> are updated to match so that testing $! against them,
120 wherever previously possible, will continue to work as expected, and all E*
121 constants found in F<errno.h> are now exported from those modules with their
122 original F<errno.h> values
124 In order to avoid breakage in existing Perl code which assigns WSAE* values to
125 $!, perl now intercepts the assignment and performs the same mapping to E*
126 values as it uses internally when assigning to $! itself.
128 However, one backwards-incompatibility remains: existing Perl code which
129 compares $! against the numeric values of the WSAE* error codes that were
130 previously assigned to $! will now be broken in those cases where a
131 corresponding E* value has been assigned instead. This is only an issue for
132 those E* values E<lt> 100, which were always exported from L<Errno> and
133 L<POSIX> with their original F<errno.h> values, and therefore could not be used
134 for WSAE* error code tests (e.g. WSAEINVAL is 10022, but the corresponding
135 EINVAL is 22). (E* values E<gt> 100, if present, were redefined to WSAE*
136 values anyway, so compatibility can be achieved by using the E* constants,
137 which will work both before and after this change, albeit using different
138 numeric values under the hood.)
142 XXX Any deprecated features, syntax, modules etc. should be listed here.
144 =head2 Module removals
146 XXX Remove this section if inapplicable.
148 The following modules will be removed from the core distribution in a
149 future release, and will at that time need to be installed from CPAN.
150 Distributions on CPAN which require these modules will need to list them as
153 The core versions of these modules will now issue C<"deprecated">-category
154 warnings to alert you to this fact. To silence these deprecation warnings,
155 install the modules in question from CPAN.
157 Note that these are (with rare exceptions) fine modules that you are encouraged
158 to continue to use. Their disinclusion from core primarily hinges on their
159 necessity to bootstrapping a fully functional, CPAN-capable Perl installation,
160 not usually on concerns over their design.
164 XXX Note that deprecated modules should be listed here even if they are listed
165 as an updated module in the L</Modules and Pragmata> section.
169 [ List each other deprecation as a =head2 entry ]
171 =head1 Performance Enhancements
177 The trie performance enhancement for regular expressions has now been extended
178 to those compiled under C</iaa>.
182 =head1 Modules and Pragmata
184 XXX All changes to installed files in F<cpan/>, F<dist/>, F<ext/> and F<lib/>
185 go here. If Module::CoreList is updated, generate an initial draft of the
186 following sections using F<Porting/corelist-perldelta.pl>, which prints stub
187 entries to STDOUT. Results can be pasted in place of the '=head2' entries
188 below. A paragraph summary for important changes should then be added by hand.
189 In an ideal world, dual-life modules would have a F<Changes> file that could be
192 [ Within each section, list entries as a =item entry ]
194 =head2 New Modules and Pragmata
204 =head2 Updated Modules and Pragmata
210 L<autodie> has been upgraded from version 2.20 to 2.21.
212 Numerous improvements have been made, many speed-related. See the F<Changes>
213 file in the CPAN distribution for full details.
217 L<B> has been upgraded from version 1.45 to 1.46.
219 The fix for [perl #118525] introduced a regression in the behaviour of
220 C<B::CV::GV>, changing the return value from a C<B::SPECIAL> object on a
221 C<NULL> C<CvGV> to C<undef>. C<B::CV::GV> again returns a C<B::SPECIAL> object
222 in this case. [perl #119351]
224 B version 1.44 (perl 5.19.2) introduced three new B::OP methods,
225 C<slabbed>, C<savefree>, C<static> and C<folded>, but these have never
226 actually worked until now. They used to croak.
230 L<B::Concise> has been upgraded from version 0.98 to 0.99.
232 The handling of the C<glob> operator, broken since Perl 5.17.6, has been fixed
233 and handling of the new kvaslice and kvhslice operators have been added.
237 L<B::Deparse> has been upgraded from version 1.22 to 1.23.
239 The new kvaslice and kvhslice operators have been added.
243 L<Carp> has been upgraded from version 1.31 to 1.32.
249 In stack traces, subroutine arguments that are strings are now quoted in a
250 consistent manner, regardless of what characters they contain and how they're
251 internally represented.
255 C<Carp> now takes care not to clobber the status variables $! and $^E.
259 C<Carp> now won't vivify the C<overload::StrVal> glob or subroutine or the
264 C<Carp> now avoids some unwanted Unicode warnings on older Perls. This doesn't
265 affect behaviour with current Perls.
269 C<Carp::Heavy> detects version mismatch with C<Carp>, to give a good error
270 message if a current (stub) C<Carp::Heavy> gets loaded by an old C<Carp> that
271 expects C<Carp::Heavy> to provide subroutines.
277 L<charnames> has been upgraded from version 1.38 to 1.39.
279 This module now works on EBCDIC platforms.
283 L<CPAN> has been upgraded from version 2.00 to 2.03-TRIAL.
285 Numerous updates and bug fixes are incorporated. See the F<Changes> file for
290 L<CPAN::Meta> has been upgraded from version 2.132140 to 2.132510.
292 No changes have been made to the installed code other than the version bump to
293 keep in sync with the latest CPAN release.
297 L<CPAN::Meta::Requirements> has been upgraded from version 2.122 to 2.123.
299 No changes have been made to the installed code other than the version bump to
300 keep in sync with the latest CPAN release.
304 L<Data::Dumper> has been upgraded from version 2.148 to 2.149.
306 This upgrade is part of a larger change to make the array interface 64-bit safe
307 by using SSize_t instead of I32 for array indices.
309 In addition, an EBCDIC fix has been applied.
313 L<Devel::Peek> has been upgraded from version 1.13 to 1.14.
315 This upgrade is part of a larger change to preserve referential identity when
316 passing C<undef> to a subroutine by using NULL rather than &PL_sv_undef for
317 nonexistent array elements.
319 In addition, C<Dump> with no args was broken in Perl 5.19.3, but has now been
324 L<diagnostics> has been upgraded from version 1.32 to 1.33.
326 C<=back> is now treated as the end of a warning description, thus keeping any
327 trailing data in the file from showing up as part of the last warning's
328 description. [perl #119817]
332 L<DynaLoader> has been upgraded from version 1.19 to 1.20.
334 The documentation now makes it clear, as has always been the case, that
335 C<dl_unload_file> is only called automatically to unload all loaded shared
336 objects if the perl interpreter was built with the C macro
337 DL_UNLOAD_ALL_AT_EXIT defined. Support for GNU DLD has also been removed.
341 L<Encode> has been upgraded from version 2.52 to 2.55.
343 An erroneous early return in C<decode_utf8> has been removed, and a bug in
344 C<_utf8_on> under COW has been fixed. Encode also now uses L<parent> rather
345 than L<base> throughout.
349 L<Errno> has been upgraded from version 1.19 to 1.20.
351 The list of E* constants exported on Windows has been updated to reflect the
352 changes made in the assignment of sockets error codes to $! (see
353 L</Incompatible Changes>).
357 L<Exporter> has been upgraded from version 5.69 to 5.70.
359 A number of typos have been corrected in the documentation.
363 L<ExtUtils::CBuilder> has been upgraded from version 0.280205 to 0.280212.
365 No changes have been made to the installed code other than the version bump to
366 keep in sync with the latest CPAN release.
370 L<ExtUtils::Command> has been upgraded from version 1.17 to 1.18.
372 No changes have been made to the installed code other than the version bump to
373 keep in sync with the latest CPAN release.
377 L<ExtUtils::MakeMaker> has been upgraded from version 6.72 to 6.76.
379 Numerous updates and bug fixes are incorporated. See the F<Changes> file for
384 L<ExtUtils::ParseXS> has been upgraded from version 3.21 to 3.23.
386 Unquoted "here-doc" markers for typemaps can now be optionally followed by a
387 semicolon, just like quoted markers. [perl #119761]
391 L<File::Find> has been upgraded from version 1.24 to 1.25.
393 Better diagnostics are now provided in the case of a failed C<chdir>.
397 L<File::Glob> has been upgraded from version 1.20 to 1.21.
399 C<glob> now warns in the context of C<use warnings "syscalls";> if the supplied
400 pattern has an internal NUL (C<"\0">) character.
404 L<FileCache> has been upgraded from version 1.08 to 1.09.
406 This upgrade is part of a larger change to use L<parent> rather than L<base>.
410 L<Hash::Util::FieldHash> has been upgraded from version 1.12 to 1.13.
412 This upgrade is part of a larger change to use L<parent> rather than L<base>.
416 L<HTTP::Tiny> has been upgraded from version 0.034 to 0.035.
418 Encoded data from C<post_form> now preserves term order if data is provided as
419 an array reference. (They are still sorted for consistency if provided as a
424 L<I18N::LangTags> has been upgraded from version 0.39 to 0.40.
426 Bosnian has now joined Croatian and Serbian in the lists of mutually
427 intelligible Slavic languages. [perl #72594]
431 L<IO> has been upgraded from version 1.28 to 1.29.
433 A minor internals-only change has been made to the XS code.
437 L<IO::Socket> has been upgraded from version 1.36 to 1.37.
439 The C<connect> method has been updated in the light of changes made in the
440 assignment of sockets error codes to $! on Windows (see L</Incompatible
445 L<IPC::Open3> has been upgraded from version 1.15 to 1.16.
447 This upgrade is part of a larger change to preserve referential identity when
448 passing C<undef> to a subroutine by using NULL rather than &PL_sv_undef for
449 nonexistent array elements.
453 L<JSON::PP> has been patched from version 2.27202 to 2.27202_01.
455 A precedence issue has been fixed in the return value of a private subroutine.
459 L<Locale::Codes> has been upgraded from version 3.26 to 3.27.
461 New codes have been added and the (deprecated) set of FIPS-10 country codes has
466 L<Math::BigInt> has been upgraded from version 1.9992 to 1.9993.
468 Cleaned up the L<Math::BigInt> and L<Math::BigFloat> documentation to be more
469 consistent with other Perl documentation. [perl #86686]
471 Added a C<bint> method for rounding towards zero. [perl #85296]
475 L<Math::BigInt::FastCalc> has been upgraded from version 0.30 to 0.31.
477 This upgrade is part of a larger change to make the array interface 64-bit safe
478 by using SSize_t instead of I32 for array indices.
482 L<Module::CoreList> has been upgraded from version 2.97 to 2.98.
484 The list of Perl versions covered has been updated.
488 L<Module::Load::Conditional> has been upgraded from version 0.54 to 0.58.
490 C<requires> has been made more robust. [cpan #83728]
494 L<Module::Metadata> has been upgraded from version 1.000014 to 1.000018.
496 The module's DESCRIPTION has been re-worded regarding safety/security to
497 satisfy CVE-2013-1437. Also, versions are now detainted if needed. [cpan
502 L<mro> has been upgraded from version 1.13 to 1.14.
504 This upgrade is part of a larger change to make the array interface 64-bit safe
505 by using SSize_t instead of I32 for array indices.
509 L<Opcode> has been upgraded from version 1.25 to 1.26.
511 The new kvaslice and kvhslice operators have been added.
515 L<parent> has been upgraded from version 0.226 to 0.228.
517 No changes have been made to the installed code other than the version bump to
518 keep in sync with the latest CPAN release.
522 L<Parse::CPAN::Meta> has been upgraded from version 1.4405 to 1.4407.
524 No changes have been made to the installed code other than the version bump to
525 keep in sync with the latest CPAN release.
529 L<Perl::OSType> has been upgraded from version 1.003 to 1.005.
531 The Unix OSType 'bitrig' has been added.
535 L<perlfaq> has been upgraded from version 5.0150043 to 5.0150044.
537 The use of C<gensym> in a number of examples has been removed, the use of C<&>
538 in subroutine calls is now clarified and several new questions have been
543 L<Pod::Html> has been upgraded from version 1.20 to 1.21.
545 This upgrade is part of a larger change to use L<parent> rather than L<base>.
549 L<POSIX> has been upgraded from version 1.34 to 1.35.
551 The list of E* constants exported on Windows has been updated to reflect the
552 changes made in the assignment of sockets error codes to $! (see
553 L</Incompatible Changes>).
557 L<re> has been upgraded from version 0.25 to 0.26.
559 This upgrade is part of a larger change to support 64-bit string lengths in the
560 regular expression engine.
564 L<Scalar::Util> has been upgraded from version 1.31 to 1.32.
566 The documentation of C<blessed> has been improved to mention the fact that
567 package "0" is defined but false.
571 L<Socket> has been upgraded from version 2.011 to 2.012.
573 Syntax errors when building on the WinCE platform have been fixed. [cpan
578 L<Storable> has been upgraded from version 2.46 to 2.47.
580 This upgrade is part of a larger change to preserve referential identity when
581 passing C<undef> to a subroutine by using NULL rather than &PL_sv_undef for
582 nonexistent array elements.
586 L<Term::ReadLine> has been upgraded from version 1.10 to 1.14.
588 Term::ReadLine::EditLine support has been added.
592 L<Test::Simple> has been patched from version 0.98 to 0.98_06.
594 A precedence issue has been fixed in the return value of a private subroutine
599 L<Time::Piece> has been upgraded from version 1.22 to 1.23.
601 Day of year parsing (like "%y%j") has been fixed.
605 L<Unicode::Collate> has been upgraded from version 0.98 to 0.99.
607 By default, out-of-range values are replaced with C<U+FFFD> (REPLACEMENT
608 CHARACTER) when C<UCA_Version> E<gt>= 22, or ignored when C<UCA_Version> E<lt>=
609 20. When C<UCA_Version> E<gt>= 22, the weights of out-of-range values can be
614 L<Unicode::UCD> has been upgraded from version 0.53 to 0.54.
616 This module now works on EBCDIC platforms.
620 L<version> has been upgraded from version 0.9903 to 0.9904.
622 No changes have been made to the installed code other than the version bump to
623 keep in sync with the latest CPAN release.
627 L<warnings> has been upgraded from version 1.18 to 1.19.
629 The C<syscalls> warnings category has been added to check for embedded NUL
630 (C<"\0">) characters in pathnames and string arguments to other system calls.
634 L<XS::Typemap> has been upgraded from version 0.10 to 0.11.
636 This upgrade is part of the change to remove the uninitialized warnings
637 exemption for uninitialized values returned by XSUBs (see the L</Selected Bug
642 =head2 Removed Modules and Pragmata
654 XXX Changes to files in F<pod/> go here. Consider grouping entries by
655 file and be sure to link to the appropriate page, e.g. L<perlfunc>.
657 =head2 New Documentation
659 =head3 L<perlrepository>
661 This document was removed (actually, renamed L<perlgit> and given a major
662 overhaul) in Perl 5.13.10, causing Perl documentation websites to show the now
663 out of date version in Perl 5.12 as the latest version. It has now been
664 restored in stub form, directing readers to current information.
666 =head2 Changes to Existing Documentation
674 New sections have been added to document the new index/value array slice and
675 key/value hash slice syntax.
679 =head3 L<perldebguts>
685 The C<&DB::goto> and C<&DB::lsub> debugger subroutines are now documented.
696 Numerous minor changes have been made to reflect changes made to the perl
697 internals in this release.
707 The L<SUPER QUICK PATCH GUIDE|perlhack/SUPER QUICK PATCH GUIDE> section has
718 A list of subroutine names used by the perl implementation is now included.
725 The following additions or changes have been made to diagnostic output,
726 including warnings and fatal error messages. For the complete list of
727 diagnostic messages, see L<perldiag>.
729 XXX New or changed warnings emitted by the core's C<C> code go here. Also
730 include any changes in L<perldiag> that reconcile it to the C<C> code.
732 =head2 New Diagnostics
734 XXX Newly added diagnostic messages go under here, separated into New Errors
743 L<delete argument is indexE<sol>value array slice, use array slice|perldiag/"delete argument is index/value array slice, use array slice">
745 (F) You used index/value array slice syntax (C<%array[...]>) as the argument to
746 C<delete>. You probably meant C<@array[...]> with an @ symbol instead.
750 L<delete argument is keyE<sol>value hash slice, use hash slice|perldiag/"delete argument is key/value hash slice, use hash slice">
752 (F) You used key/value hash slice syntax (C<%hash{...}>) as the argument to
753 C<delete>. You probably meant C<@hash{...}> with an @ symbol instead.
763 L<Invalid \0 character in %s for %s: %s\0%s|perldiag/"Invalid \0 character in %s for %s: %s\0%s">
765 (W syscalls) Embedded \0 characters in pathnames or other system call arguments
766 produce a warning as of 5.20. The parts after the \0 were formerly ignored by
771 L<Possible precedence issue with control flow operator|perldiag/"Possible precedence issue with control flow operator">
773 (W syntax) There is a possible problem with the mixing of a control flow
774 operator (e.g. C<return>) and a low-precedence operator like C<or>. Consider:
776 sub { return $a or $b; }
780 sub { (return $a) or $b; }
782 Which is effectively just:
786 Either use parentheses or the high-precedence variant of the operator.
788 Note this may be also triggered for constructs like:
794 L<Scalar value %%s[%s] better written as $%s[%s]|perldiag/"Scalar value %%s[%s] better written as $%s[%s]">
796 (W syntax) In scalar context, you've used an array index/value slice (indicated
797 by %) to select a single element of an array. Generally it's better to ask for
798 a scalar value (indicated by $). The difference is that C<$foo[&bar]> always
799 behaves like a scalar, both in the value it returns and when evaluating its
800 argument, while C<%foo[&bar]> provides a list context to its subscript, which
801 can do weird things if you're expecting only one subscript. When called in
802 list context, it also returns the index (what C<&bar> returns) in addition to
807 L<Scalar value %%s{%s} better written as $%s{%s}|perldiag/"Scalar value %%s{%s} better written as $%s{%s}">
809 (W syntax) In scalar context, you've used a hash key/value slice (indicated by
810 %) to select a single element of a hash. Generally it's better to ask for a
811 scalar value (indicated by $). The difference is that C<$foo{&bar}> always
812 behaves like a scalar, both in the value it returns and when evaluating its
813 argument, while C<@foo{&bar}> and provides a list context to its subscript,
814 which can do weird things if you're expecting only one subscript. When called
815 in list context, it also returns the key in addition to the value.
819 =head2 Changes to Existing Diagnostics
821 XXX Changes (i.e. rewording) of diagnostic messages go here
827 Warnings and errors from the regexp engine are now UTF-8 clean
831 The "Unknown switch condition" error message has some slight changes. This
832 error triggers when there is an unknown condition in a C<(?(foo))> conditional.
833 The error message used to read:
835 Unknown switch condition (?(%s in regex;
837 But what %s could be was mostly up to luck. For C<(?(foobar))>, you might have
838 seen "fo" or "f". For Unicode characters, you would generally get a corrupted
839 string. The message has been changed to read:
841 Unknown switch condition (?(...)) in regex;
843 Additionally, the C<'E<lt>-- HERE'> marker in the error will now point to the
844 correct spot in the regex.
848 The "%s "\x%X" does not map to Unicode" warning is now correctly listed as a
849 severe warning rather than as a fatal error.
853 =head1 Utility Changes
855 XXX Changes to installed programs such as F<perlbug> and F<xsubpp> go here.
856 Most of these are built within the directories F<utils> and F<x2p>.
858 [ List utility changes as a =head3 entry for each utility and =item
859 entries for each change
860 Use L<XXX> with program names to get proper documentation linking. ]
868 L<find2perl> now handles C<?> wildcards correctly. [perl #113054]
872 =head1 Configuration and Compilation
874 XXX Changes to F<Configure>, F<installperl>, F<installman>, and analogous tools
875 go here. Any other changes to the Perl build process should be listed here.
876 However, any platform-specific changes should be listed in the
877 L</Platform Support> section, instead.
879 [ List changes as a =item entry ].
885 The F<Makefile.PL> for C<SDBM_File> now generates a better F<Makefile>, which
886 avoids a race condition during parallel makes, which could cause the build to
887 fail. This is the last known parallel make problem (on *nix platforms), and
888 therefore we believe that a parallel make should now always be error free.
892 Strictly only for a build where build files such as F<Makefile.SH> have not
893 been updated by C<git> in an already configured and built tree.
899 XXX Any significant changes to the testing of a freshly built perl should be
900 listed here. Changes which create B<new> files in F<t/> go here as do any
901 large changes to the testing harness (e.g. when parallel testing was added).
902 Changes to existing files in F<t/> aren't worth summarizing, although the bugs
903 that they represent may be covered elsewhere.
905 [ List each test improvement as a =item entry ]
911 The test script F<t/bigmem/regexp.t> has been added to test that regular
912 expression matches on very large strings now succeed as expected.
916 A bug that was fixed in Perl 5.15.4 is now tested by the new test script
917 F<t/io/eintr_print.t>. [perl #119097]
921 The new test scripts F<t/op/kvaslice.t> and F<t/op/kvhslice.t> test the new
922 index/value array slice and key/value hash slice syntax respectively.
926 Various cases of C<die>, C<last>, C<goto> and C<exit> triggering C<DESTROY> are
927 now tested by the new test script F<t/op/rt119311.t>.
931 The new test script F<t/op/waitpid.t> tests the fix for [perl #85228] (see
932 L</Selected Bug Fixes>).
936 The latest copyright years in the top-level F<README> file and the B<perl -v>
937 output are now tested as matching each other by the new test script
938 F<t/porting/copyright.t>
942 The new test script F<t/win32/signal.t> tests that $! and $^E are now preserved
943 across signal handlers by the Win32 signal emulation code.
947 The test script F<t/x2p/find2perl.t> has been added to test the F<find2perl>
948 program on platforms where it is practical to do so.
952 =head1 Platform Support
954 XXX Any changes to platform support should be listed in the sections below.
956 [ Within the sections, list each platform as a =item entry with specific
957 changes as paragraphs below it. ]
961 XXX List any platforms that this version of perl compiles on, that previous
962 versions did not. These will either be enabled by new files in the F<hints/>
963 directories, or new subdirectories and F<README> files at the top level of the
970 Compile support has been added for Bitrig, a fork of OpenBSD.
974 =head2 Discontinued Platforms
976 Configure hints and conditional code for several very old platforms has been
977 removed. We have not received reports for these in many years, typically not
984 Configure support for the 3b1, also known as the AT&T Unix PC (and the similar
985 AT&T 7300), has been removed.
989 =head2 Platform-Specific Notes
991 XXX List any changes for specific platforms. This could include configuration
992 and compilation changes or changes in portability/compatibility. However,
993 changes within modules for platforms should generally be listed in the
994 L</Modules and Pragmata> section.
1000 C<rename> and C<link> on Win32 now set C<$!> to ENOSPC and EDQUOT when appropriate. [perl #119857]
1004 Perl now builds again on WinCE, following locale-related breakage (WinCE has
1005 non-existent locale support) introduced around 5.19.1. [perl #119443]
1007 The building of XS modules has largely been restored. Several still cannot
1008 (yet) be built but it is now possible to build Perl on WinCE with only a couple
1009 of further patches (to L<Socket> and L<ExtUtils::MakeMaker>), hopefully to be
1014 The BSD compatibility library C<libbsd> is no longer required for builds.
1018 =head1 Internal Changes
1020 XXX Changes which affect the interface available to C<XS> code go here. Other
1021 significant internal changes for future core maintainers should be noted as
1024 [ List each change as a =item entry ]
1030 The internal representation has changed for the match variables $1, $2 etc.,
1031 $`, $&, $', ${^PREMATCH}, ${^MATCH} and ${^POSTMATCH}. It uses slightly less
1032 memory, avoids string comparisons and numeric conversions during lookup, and
1033 uses 23 fewer lines of C. This change should not affect any external code.
1037 Arrays now use NULL internally to represent unused slots, instead of
1038 &PL_sv_undef. &PL_sv_undef is no longer treated as a special value, so
1039 av_store(av, 0, &PL_sv_undef) will cause element 0 of that array to hold a
1040 read-only undefined scalar. C<$array[0] = anything> will croak and
1041 C<\$array[0]> will compare equal to C<\undef>.
1045 The SV returned by HeSVKEY_force() now correctly reflects the UTF8ness
1046 of the underlying hash key when that key is not stored as a SV. [perl
1051 Certain rarely used functions and macros available to C<XS> code are
1052 now, or are planned to be deprecated. These are:
1053 C<utf8n_to_uvuni> (use C<utf8_to_uvchr_buf> instead),
1054 C<utf8_to_uni_buf> (use C<utf8_to_uvchr_buf> instead),
1055 C<valid_utf8_to_uvuni> (use C<utf8_to_uvchr_buf> instead),
1056 C<uvuni_to_utf8> (use C<uvchr_to_utf8> instead),
1057 C<NATIVE_TO_NEED> (this did not work properly anyway),
1058 and C<ASCII_TO_NEED> (this did not work properly anyway).
1060 Starting in this release, almost never does application code need to
1061 distinguish between the platform's character set and Latin1, on which the
1062 lowest 256 characters of Unicode are based.
1066 =head1 Selected Bug Fixes
1068 XXX Important bug fixes in the core language are summarized here. Bug fixes in
1069 files in F<ext/> and F<lib/> are best summarized in L</Modules and Pragmata>.
1071 [ List each fix as a =item entry ]
1077 The value of $^E is now saved across signal handlers on Windows. [perl #85104]
1081 A lexical filehandle (as in C<open my $fh...>) is usually given a name based on
1082 the current package and the name of the variable, e.g. "main::$fh". Under
1083 recursion, the filehandle was losing the "$fh" part of the name. This has been
1088 Perl 5.19.3 accidentally extended the previous bug to all closures, even when
1089 not called recursively, i.e. lexical handles in closure would always be called
1090 "main::" or "MyPackage::" etc. This has been fixed.
1094 Uninitialized values returned by XSUBs are no longer exempt from uninitialized
1095 warnings. [perl #118693]
1099 C<elsif ("")> no longer erroneously produces a warning about void context.
1104 Passing C<undef> to a subroutine now causes @_ to contain the same read-only
1105 undefined scalar that C<undef> returns. Furthermore, C<exists $_[0]> will now
1106 return true if C<undef> was the first argument. [perl #7508, #109726]
1110 Passing a nonexistent array element to a subroutine does not usually autovivify
1111 it unless the subroutine modifies its argument. This did not work correctly
1112 with negative indices and with nonexistent elements within the array. The
1113 element would be vivified immediately. The delayed vivification has been
1114 extended to work with those. [perl #118691]
1118 Assigning references or globs to the scalar returned by $#foo after the @foo
1119 array has been freed no longer causes assertion failures on debugging builds
1120 and memory leaks on regular builds.
1124 Perl 5.19.2 threw line numbers off after some cases of line breaks following
1130 This has been fixed. [perl #118931]
1134 On 64-bit platforms, large ranges like 1..1000000000000 no longer crash, but
1135 eat up all your memory instead. [perl #119161]
1139 C<__DATA__> now puts the C<DATA> handle in the right package, even if the
1140 current package has been renamed through glob assignment.
1144 The string position set by C<pos> could shift if the string changed
1145 representation internally to or from utf8. This could happen, e.g., with
1146 references to objects with string overloading.
1150 Taking references to the return values of two C<pos> calls with the same
1151 argument, and then assigning a reference to one and C<undef> to the other,
1152 could result in assertion failures or memory leaks.
1156 Elements of @- and @+ now update correctly when they refer to nonexistent
1157 captures. Previously, a referenced element (C<$ref = \$-[1]>) could refer to
1158 the wrong match after subsequent matches.
1162 When C<die>, C<last>, C<next>, C<redo>, C<goto> and C<exit> unwind the scope,
1163 it is possible for C<DESTROY> recursively to call a subroutine or format that
1164 is currently being exited. It that case, sometimes the lexical variables
1165 inside the sub would start out having values from the outer call, instead of
1166 being undefined as they should. This has been fixed. [perl #119311]
1170 ${^MPEN} is no longer treated as a synonym for ${^MATCH}.
1174 Perl now tries a little harder to return the correct line number in
1175 C<(caller)[2]>. [perl #115768]
1179 Line numbers inside multiline quote-like operators are now reported correctly.
1184 C<#line> directives inside code embedded in quote-like operators are now
1189 Line numbers are now correct inside the second here-doc when two here-doc
1190 markers occur on the same line.
1194 Starting with Perl 5.12, line numbers were off by one if the B<-d> switch was
1195 used on the #! line. Now they are correct.
1199 Perl 5.19.2 inadvertently stopped some lines of code from being available to
1200 the debugger if C<=E<gt>> occurred at the beginning of a line and the previous
1201 line ended with a keyword. This is now fixed.
1205 Perl 5.19.2 allowed the PERL5DB environment variable to contain multiple lines
1206 of code, but those lines were not made available to the debugger. Now they are
1207 all stuffed into line number 0, accessible via C<$dbline[0]> in the debugger.
1211 An optimisation in Perl 5.18 made incorrect assumptions causing a bad
1212 interaction with the L<Devel::CallParser> CPAN module. If the module was
1213 loaded then lexical variables declared in separate statements following a
1214 C<my(...)> list might fail to be cleared on scope exit.
1218 C<&xsub> and C<goto &xsub> calls now allow the called subroutine to autovivify
1223 C<&xsub> and C<goto &xsub> no longer crash if *_ has been undefined and has no
1224 ARRAY entry (i.e. @_ does not exist).
1228 C<&xsub> and C<goto &xsub> now work with tied @_.
1232 Overlong identifiers no longer cause a buffer overflow (and a crash). They
1233 started doing so in Perl 5.18.
1237 The warning "Scalar value @hash{foo} better written as $hash{foo}" now produces
1238 far fewer false positives. In particular, C<@hash{+function_returning_a_list}>
1239 and C<@hash{ qw "foo bar baz" }> no longer warn. The same applies to array
1240 slices. [perl #28380, #114024]
1244 C< $! = EINVAL; waitpid(0, WNOHANG); > no longer goes into an internal infinite
1249 Perl 5.19.3 accidentally caused C<\(1+2)> to return a reference to the same
1250 mutable scalar each time, so that modifications affect future evaluations.
1251 This has been fixed. [perl #119501]
1255 =head1 Known Problems
1257 XXX Descriptions of platform agnostic bugs we know we can't fix go here. Any
1258 tests that had to be C<TODO>ed for the release would be noted here. Unfixed
1259 platform specific bugs also go here.
1261 [ List each fix as a =item entry ]
1273 XXX If any significant core contributor has died, we've added a short obituary
1276 =head1 Acknowledgements
1278 XXX Generate this with:
1280 perl Porting/acknowledgements.pl v5.19.3..HEAD
1282 =head1 Reporting Bugs
1284 If you find what you think is a bug, you might check the articles recently
1285 posted to the comp.lang.perl.misc newsgroup and the perl bug database at
1286 http://rt.perl.org/perlbug/ . There may also be information at
1287 http://www.perl.org/ , the Perl Home Page.
1289 If you believe you have an unreported bug, please run the L<perlbug> program
1290 included with your release. Be sure to trim your bug down to a tiny but
1291 sufficient test case. Your bug report, along with the output of C<perl -V>,
1292 will be sent off to perlbug@perl.org to be analysed by the Perl porting team.
1294 If the bug you are reporting has security implications, which make it
1295 inappropriate to send to a publicly archived mailing list, then please send it
1296 to perl5-security-report@perl.org. This points to a closed subscription
1297 unarchived mailing list, which includes all the core committers, who will be
1298 able to help assess the impact of issues, figure out a resolution, and help
1299 co-ordinate the release of patches to mitigate or fix the problem across all
1300 platforms on which Perl is supported. Please only use this address for
1301 security issues in the Perl core, not for modules independently distributed on
1306 The F<Changes> file for an explanation of how to view exhaustive details on
1309 The F<INSTALL> file for how to build Perl.
1311 The F<README> file for general stuff.
1313 The F<Artistic> and F<Copying> files for copyright information.