=encoding utf8 =for comment This has been completed up to 0aae26c14, except for: 803e389 rurban CYG17 utf8 paths d9298c1 rurban mymalloc isn't thread safe =head1 NAME [ this is a template for a new perldelta file. Any text flagged as XXX needs to be processed before release. ] perldelta - what is new for perl v5.15.8 =head1 DESCRIPTION This document describes differences between the 5.15.7 release and the 5.15.8 release. If you are upgrading from an earlier release such as 5.15.6, first read L, which describes differences between 5.15.6 and 5.15.7. =head1 Notice XXX Any important notices here =head1 Core Enhancements XXX New core language features go here. Summarise user-visible core language enhancements. Particularly prominent performance optimisations could go here, but most should go in the L section. [ List each enhancement as a =head2 entry ] =head2 Improved ability to mix locales and Unicode, including UTF-8 locales An optional parameter has been added to C use locale ':not_characters'; which tells Perl to use all but the C and C portions of the current locale. Instead, the character set is assumed to be Unicode. This allows locales and Unicode to be seamlessly mixed, including the increasingly frequent UTF-8 locales. When using this hybrid form of locales, the C<:locale> layer to the L pragma can be used to interface with the file system, and there are CPAN modules available for ARGV and environment variable conversions. Full details are in L. =head2 New function C and corresponding escape sequence C<\F> for Unicode foldcase Unicode foldcase is an extension to lowercase that gives better results when comparing two strings case-insensitively. It has long been used internally in regular expression C matching. Now it is available explicitly through the new C function call (enabled by S>, or C, or explicitly callable via C) or through the new C<\F> sequence in double-quotish strings. Full details are in L. =head2 C<_> in subroutine prototypes The C<_> character in subroutine prototypes is now allowed before C<@> or C<%>. =head2 Supports (I) Unicode 6.1 Besides the addition of whole new scripts, and new characters in existing scripts, this new version of Unicode, as always, makes some changes to existing characters. One change that may trip up some applications is that the General Category of two characters in the Latin-1 range, PILCROW SIGN and SECTION SIGN, has been changed from Other_Symbol to Other_Punctuation. The same change has been made for a character in each of Tibetan, Ethiopic, and Aegean. The code points U+3248..U+324F (CIRCLED NUMBER TEN ON BLACK SQUARE through CIRCLED NUMBER EIGHTY ON BLACK SQUARE) have had their General Category changed from Other_Symbol to Other_Numeric. The Line Break property has changes for Hebrew and Japanese; and as a consequence of other changes in 6.1, the Perl regular expression construct C<\X> now works differently for some characters in Thai and Lao. New aliases (synonyms) have been defined for many property values; these, along with the previously existing ones, are all cross indexed in L. The return value of C is affected by other changes: Code point Old Name New Name U+000A LINE FEED (LF) LINE FEED U+000C FORM FEED (FF) FORM FEED U+000D CARRIAGE RETURN (CR) CARRIAGE RETURN U+0085 NEXT LINE (NEL) NEXT LINE U+008E SINGLE-SHIFT 2 SINGLE-SHIFT-2 U+008F SINGLE-SHIFT 3 SINGLE-SHIFT-3 U+0091 PRIVATE USE 1 PRIVATE USE-1 U+0092 PRIVATE USE 2 PRIVATE USE-2 U+2118 SCRIPT CAPITAL P WEIERSTRASS ELLIPTIC FUNCTION Perl will accept any of these names as input, but C now returns the new name of each pair. The change for U+2118 is considered by Unicode to be a correction, that is the original name was a mistake (but again, it will remain forever valid to use it to refer to U+2118). But most of these changes are the fallout of the mistake Unicode 6.0 made in naming a character used in Japanese cell phones to be "BELL", which conflicts with the long standing industry use of (and Unicode's recommendation to use) that name to mean the ASCII control character at U+0007. As a result, that name has been deprecated in Perl since v5.14; and any use of it will raise a warning message (unless turned off). The name "ALERT" is now the preferred name for this code point, with "BEL" being an acceptable short form. The name for the new cell phone character, at code point U+1F514, remains undefined in this version of Perl (hence we don't quite implement all of Unicode 6.1), but starting in v5.18, BELL will mean this character, and not U+0007. Unicode has taken steps to make sure that this sort of mistake does not happen again. The Standard now includes all the generally accepted names and abbreviations for control characters, whereas previously it didn't (though there were recommended names for most of them, which Perl used). This means that most of those recommended names are now officially in the Standard. Unicode did not recommend names for the four code points listed above between U+008E and U+008F, and in standardizing them Unicode subtly changed the names that Perl had previously given them, by replacing the final blank in each name by a hyphen. Unicode also officially accepts names that Perl had deprecated, such as FILE SEPARATOR. Now the only deprecated name is BELL. Finally, Perl now uses the new official names instead of the old (now considered obsolete) names for the first four code points in the list above (the ones which have the parentheses in them). Now that the names have been placed in the Unicode standard, these kinds of changes should not happen again, though corrections, such as to U+2118, are still possible. Unicode also added some name abbreviations, which Perl now accepts: SP for SPACE; TAB for CHARACTER TABULATION; NEW LINE, END OF LINE, NL, and EOL for LINE FEED; LOCKING-SHIFT ONE for SHIFT OUT; LOCKING-SHIFT ZERO for SHIFT IN; and ZWNBSP for ZERO WIDTH NO-BREAK SPACE. More details on this version of Unicode are provided in L. =head2 Added C This function is designed to replace the deprecated L function. It includes an extra parameter to make sure it doesn't read past the end of the input buffer. =head1 Security XXX Any security-related notices go here. In particular, any security vulnerabilities closed should be noted here rather than in the L section. [ List each security issue as a =head2 entry ] =head2 Use C and not C The latter function is now deprecated because its API is insufficient to guarantee that it doesn't read (up to 12 bytes in the worst case) beyond the end of its input string. See L. =head1 Incompatible Changes XXX For a release on a stable branch, this section aspires to be: There are no changes intentionally incompatible with 5.XXX.XXX If any exist, they are bugs, and we request that you submit a report. See L below. [ List each incompatible change as a =head2 entry ] =head2 Special blocks called in void context Special blocks (C, C, C, C, C) are now called in void context. This avoids wasteful copying of the result of the last statement [perl #108794]. =head2 The C pragma and regexp objects With C, regular expression objects returned by C are now stringified as "Regexp=REGEXP(0xbe600d)" instead of the regular expression itself [perl #108780]. =head2 Two XS typemap Entries removed Two presumably unused XS typemap entries have been removed from the core typemap: T_DATAUNIT and T_CALLBACK. If you are, against all odds, a user of these, please see the instructions on how to regain them in L. =head2 Unicode 6.1 has incompatibilities with Unicode 6.0 These are detailed in L above. =head2 Changed returns for some properties in C The return values for C have been changed for some properties to make the returned lists significantly smaller. This allows those lists to be searched faster. This function was introduced earlier in the v5.15 series of releases, and the API will not be considered stable until v5.16. See L for details on the new interface. =head2 C<$$> and C no longer emulate POSIX semantics under LinuxThreads The POSIX emulation of C<$$> and C under the obsolete LinuxThreads implementation has been removed (the C<$$> emulation was actually removed in v5.15.0). This only impacts users of Linux 2.4 and users of Debian GNU/kFreeBSD up to and including 6.0, not the vast majority of Linux installations that use NPTL threads. This means that C like C<$$> is now always guaranteed to return the OS's idea of the current state of the process, not perl's cached version of it. See the documentation for L<$$|perlvar/$$> for details. =head2 Which Non-ASCII characters get quoted by C and C<\Q> has changed This is unlikely to result in a real problem, as Perl does not attach special meaning to any non-ASCII character, so it is currently irrelevant which are quoted or not. This change fixes bug [perl #77654] and bring Perl's behavior more into line with Unicode's recommendations. See L. =head1 Deprecations XXX Any deprecated features, syntax, modules etc. should be listed here. In particular, deprecated modules should be listed here even if they are listed as an updated module in the L section. [ List each deprecation as a =head2 entry ] =head2 C This function is deprecated because it could read beyond the end of the input string. Use the new L instead. =head1 Performance Enhancements XXX Changes which enhance performance without changing behaviour go here. There may well be none in a stable release. [ List each enhancement as a =item entry ] =over 4 =item * XXX =back =head1 Modules and Pragmata XXX All changes to installed files in F, F, F and F go here. If Module::CoreList is updated, generate an initial draft of the following sections using F, which prints stub entries to STDOUT. Results can be pasted in place of the '=head2' entries below. A paragraph summary for important changes should then be added by hand. In an ideal world, dual-life modules would have a F file that could be cribbed. [ Within each section, list entries as a =item entry ] =head2 New Modules and Pragmata =over 4 =item * The C PerlIO layer is no longer implemented by perl itself, but has been moved out into the new L module. =back =head2 Updated Modules and Pragmata =over 4 =item * L has been upgraded from version 0.03 to version 0.04. List slices no longer modify items on the stack belonging to outer lists [perl #109570]. =item * L has been upgraded from version 1.33 to version 1.34. C now has a C method, corresponding to a new internal field added in 5.15.4 [perl #108860]. =item * L has been upgraded from version 1.24 to version 1.25. It now puts a dot after the file and line number, just like errors from C [perl #106538]. =item * L has been upgraded from version 2.045 to version 2.049. =item * L has been upgraded from version 2.045 to version 2.049. Include zlib 1.2.6 source =item * L has been upgraded from version 2.046 to version 2.049. =item * L has been upgraded from version 2.113640 to version 2.120351. Work around a memory leak bug involving version objects in boolean context. =item * L has been upgraded from version 0.005 to version 0.007. =item * L has been upgraded from version 0.9116 to version 0.9118. =item * L has been upgraded from version 0.60 to version 0.62. =item * L has been upgraded from version 1.824 to version 1.826. =item * L has been upgraded from version 1.27 to version 1.28. When searching for F, it no longer uses paths that were only relevant on Perl 5.004 and earlier. =item * L has been upgraded from version 3.12 to version 3.15. The new version comes with important tools for sharing typemaps between different CPAN distributions. =item * L has been upgraded from version 2.21 to version 2.23. It no longer emits warnings when copying files with newlines in their names [perl #109104]. =item * L has been upgraded from version 0.72 to version 0.76. =item * L has been upgraded from version 1.58 to version 1.59. This avoids a new core warning. =item * L has been upgraded from version 1.000007 to version 1.000009. Adds C method to generate a CPAN META provides data structure correctly; use of C is discouraged. =item * L has been upgraded from version 1.4401 to version 1.4402. =item * L has been upgraded from version 5.0150038 to version 5.0150039. =item * L has been upgraded from version 1.04 to version 1.05. F is now generated at perl build time from annotations in F. This will ensure that L and L remain in synchronisation. =item * L has been upgraded from version 1.37 to version 1.51. =item * L has been upgraded from version 1.07 to version 1.08. Its C method now supports L event loops, and not just L. A more general mechanism has been proposed, so this may be reverted before Perl 5.16 [perl #108470]. =item * L has been upgraded from version 1.97 to version 1.98. =item * L has been upgraded from version 1.9724 to version 1.9725. C no longer corrupts the Perl stack. =item * L has been upgraded from version 0.39 to 0.40. The only change is to fix a formatting error in the Pod. =item * L has been upgraded from version 0.101021 to version 0.101022. =back =head2 Removed Modules and Pragmata =over 4 =item * F has been added, to test that changes to F do not inadvertently break the build of L. =back =head1 Documentation XXX Changes to files in F go here. Consider grouping entries by file and be sure to link to the appropriate page, e.g. L. =head2 New Documentation XXX Changes which create B files in F go here. =head3 L The new manual describes the XS typemapping mechanism in unprecedented detail and combines new documentation with information extracted from L and the previously unofficial list of all core typemaps. =head3 L XXX Description of the purpose of the new file here =head2 Changes to Existing Documentation XXX Changes which significantly change existing files in F go here. However, any changes to F should go in the L section. =head3 L =over 4 =item * XXX Description of the change here =back =head1 Diagnostics The following additions or changes have been made to diagnostic output, including warnings and fatal error messages. For the complete list of diagnostic messages, see L. XXX New or changed warnings emitted by the core's C code go here. Also include any changes in L that reconcile it to the C code. [ Within each section, list entries as a =item entry that links to perldiag, e.g. =item * L ] =head2 New Diagnostics XXX Newly added diagnostic messages go here =head3 New Errors =over 4 =item * XXX L =back =head3 New Warnings =over 4 =item * XXX L =back =head2 Changes to Existing Diagnostics XXX Changes (i.e. rewording) of diagnostic messages go here =over 4 =item * XXX Describe change here =back =head1 Utility Changes XXX Changes to installed programs such as F and F go here. Most of these are built within the directories F and F. [ List utility changes as a =head3 entry for each utility and =item entries for each change Use L with program names to get proper documentation linking. ] =head3 L =over 4 =item * XXX =back =head1 Configuration and Compilation XXX Changes to F, F, F, and analogous tools go here. Any other changes to the Perl build process should be listed here. However, any platform-specific changes should be listed in the L section, instead. [ List changes as a =item entry ]. =over 4 =item * XXX =back =head1 Testing XXX Any significant changes to the testing of a freshly built perl should be listed here. Changes which create B files in F go here as do any large changes to the testing harness (e.g. when parallel testing was added). Changes to existing files in F aren't worth summarising, although the bugs that they represent may be covered elsewhere. [ List each test improvement as a =item entry ] =over 4 =item * XXX =item * The test suite for typemaps has been extended to cover a larger fraction of the core typemaps. =back =head1 Platform Support XXX Any changes to platform support should be listed in the sections below. [ Within the sections, list each platform as a =item entry with specific changes as paragraphs below it. ] =head2 New Platforms XXX List any platforms that this version of perl compiles on, that previous versions did not. These will either be enabled by new files in the F directories, or new subdirectories and F files at the top level of the source tree. =over 4 =item XXX-some-platform XXX =back =head2 Discontinued Platforms XXX List any platforms that this version of perl no longer compiles on. =over 4 =item XXX-some-platform XXX =back =head2 Platform-Specific Notes XXX List any changes for specific platforms. This could include configuration and compilation changes or changes in portability/compatibility. However, changes within modules for platforms should generally be listed in the L section. =over 4 =item XXX-some-platform XXX =back =head1 Internal Changes XXX Changes which affect the interface available to C code go here. Other significant internal changes for future core maintainers should be noted as well. [ List each change as a =item entry ] =over 4 =item * XXX =back =head1 Selected Bug Fixes XXX Important bug fixes in the core language are summarised here. Bug fixes in files in F and F are best summarised in L. [ List each fix as a =item entry ] =over 4 =item * C<~~> now correctly handles the precedence of Any~~Object, and is not tricked by an overloaded object on the left-hand side. =item * C no longer warns about unopened filehandles [perl #71002]. =item * C on an unopened filehandle now warns consistently, instead of skipping the warning at times. =item * A change in an earlier 5.15 release caused warning hints to propagate into C. This has been fixed [rt.cpan.org #72767]. =item * Starting with 5.12.0, Perl used to get its internal bookkeeping muddled up after assigning C<${ qr// }> to a hash element and locking it with L. This could result in double frees, crashes or erratic behaviour. =item * In 5.15.7, some typeglobs in the CORE namespace were made read-only by mistake. This has been fixed [rt.cpan.org #74289]. =item * C<-t> now works when stacked with other filetest operators [perl #77388]. =item * Stacked filetest operators now only call FETCH once on a tied argument. =item * C would sometimes refuse to match at the end of a string that ends with "\n". This has been fixed [perl #109206]. =item * C and C now match identically (when not under a differing locale). This fixes a regression introduced in 5.14 in which the first expression could match characters outside of ASCII, such as the KELVIN SIGN. =item * Method calls whose arguments were all surrounded with C or C (as in C<<$object->method(my($a,$b)) >>) used to force lvalue context on the subroutine. This would prevent lvalue methods from returning certain values. Due to lvalue fixes earlier in the 5.15.x series, it would also prevent non-lvalue methods from being called [perl #109264]. =for comment This bug I affect earlier stable releases. It is just the last sentence that does not apply to 5.14. =item * The C C function no longer tries to modify its argument, resulting in errors [perl #108994]. =item * C now works properly with magical variables. =item * C now works properly non-PVs. =item * C and C now use locale rules under C when the platform supports that. Previously, they used the platform's native character set. =item * A regression introduced in 5.13.6 was fixed. This involved an inverted bracketed character class in a regular expression that consisted solely of a Unicode property, that property wasn't getting inverted outside the Latin1 range. =item * C now quotes consistently the same non-ASCII characters under C, regardless of whether the string is encoded in UTF-8 or not, hence fixing the last vestiges (we hope) of the infamous L. [perl #77654]. Which of these code points is quoted has changed, based on Unicode's recommendations. See L for details. =back =head1 Known Problems XXX Descriptions of platform agnostic bugs we know we can't fix go here. Any tests that had to be Ced for the release would be noted here, unless they were specific to a particular platform (see below). This is a list of some significant unfixed bugs, which are regressions from either 5.XXX.XXX or 5.XXX.XXX. [ List each fix as a =item entry ] =over 4 =item * XXX =back =head1 Obituary XXX If any significant core contributor has died, we've added a short obituary here. =head1 Acknowledgements XXX Generate this with: perl Porting/acknowledgements.pl v5.15.7..HEAD =head1 Reporting Bugs If you find what you think is a bug, you might check the articles recently posted to the comp.lang.perl.misc newsgroup and the perl bug database at http://rt.perl.org/perlbug/ . There may also be information at http://www.perl.org/ , the Perl Home Page. If you believe you have an unreported bug, please run the L program included with your release. Be sure to trim your bug down to a tiny but sufficient test case. Your bug report, along with the output of C, will be sent off to perlbug@perl.org to be analysed by the Perl porting team. If the bug you are reporting has security implications, which make it inappropriate to send to a publicly archived mailing list, then please send it to perl5-security-report@perl.org. This points to a closed subscription unarchived mailing list, which includes all the core committers, who will be able to help assess the impact of issues, figure out a resolution, and help co-ordinate the release of patches to mitigate or fix the problem across all platforms on which Perl is supported. Please only use this address for security issues in the Perl core, not for modules independently distributed on CPAN. =head1 SEE ALSO The F file for an explanation of how to view exhaustive details on what changed. The F file for how to build Perl. The F file for general stuff. The F and F files for copyright information. =cut