=encoding utf8 =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 v5.27.7 =head1 DESCRIPTION This document describes differences between the 5.27.6 release and the 5.27.7 release. If you are upgrading from an earlier release such as 5.27.5, first read L, which describes differences between 5.27.5 and 5.27.6. =head1 Notice XXX Any important notices here =head1 Core Enhancements XXX New core language features go here. Summarize 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 The C C<%j> format size modifier is now available with pre-C99 compilers The actual size used depends on the platform, so remains unportable. =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 ] =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 Over-radix digits in floating point literals Octal and binary floating point literals used to permit any hexadecimal digit to appear after the radix point. The digits are now restricted to those appropriate for the radix, as digits before the radix point always were. =head1 Deprecations XXX Any deprecated features, syntax, modules etc. should be listed here. =head2 Assignment to C<$[> will be fatal in Perl 5.30 Assigning a non-zero value to L|perlvar/$[> has been deprecated since Perl 5.12, but was never given a deadline for removal. This has now been scheduled for Perl 5.30. =head2 hostname() won't accept arguments in Perl 5.32 Passing arguments to C was already deprecated, but didn't have a removal date. This has now been scheduled for Perl 5.32. [perl #124349] =head2 Module removals XXX Remove this section if not applicable. The following modules will be removed from the core distribution in a future release, and will at that time need to be installed from CPAN. Distributions on CPAN which require these modules will need to list them as prerequisites. The core versions of these modules will now issue C<"deprecated">-category warnings to alert you to this fact. To silence these deprecation warnings, install the modules in question from CPAN. Note that these are (with rare exceptions) fine modules that you are encouraged to continue to use. Their disinclusion from core primarily hinges on their necessity to bootstrapping a fully functional, CPAN-capable Perl installation, not usually on concerns over their design. =over =item L and its associated Country, Currency and Language modules XXX Note that deprecated modules should be listed here even if they are listed as an updated module in the L section. =back [ List each other deprecation as a =head2 entry ] =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 an =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. 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. The list of new and updated modules is modified automatically as part of preparing a Perl release, so the only reason to manually add entries here is if you're summarising the important changes in the module update. (Also, if the manually-added details don't match the automatically-generated ones, the release manager will have to investigate the situation carefully.) [ Within each section, list entries as an =item entry ] =head2 New Modules and Pragmata =over 4 =item * XXX Remove this section if not applicable. =back =head2 Updated Modules and Pragmata =over 4 =item * L has been upgraded from version 3.54 to 3.55 B: L is deprecated in core and will be removed from Perl 5.30. =item * L has been upgraded from version 2.19 to 2.20. The documentation now better describes the problems that arise when returning values from threads, and no longer warns about creating threads in C blocks. [perl #96538] =item * L has been upgraded from version 2.167_02 to 2.169. Quoting of glob names now obeys the Useqq option [perl #119831]. Attempts to set an option to C through a combined getter/setter method are no longer mistaken for getter calls [perl #113090]. =item * L has been upgraded from version 1.2203 to 1.23. A title for the HTML document will now be automatically generated by default from a "NAME" section in the POD document, as it used to be before the module was rewritten to use L to do the core of its job. [perl #110520] =back =head2 Removed Modules and Pragmata =over 4 =item * XXX =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 XXX Description of the purpose of the new file here =head2 Changes to Existing Documentation We have attempted to update the documentation to reflect the changes listed in this document. If you find any we have missed, send email to L. XXX Changes which significantly change existing files in F go here. However, any changes to F should go in the L section. Additionally, the following selected changes have been made: =head3 L The API functions C, C, and C are now documented comprehensively, where previously the only documentation was a reference to the L tutorial. The documentation of C has been belatedly updated to account for the removal of lexical C<$_>. The API functions C and C are documented much more comprehensively than before. =head3 L The general explanation of operator precedence and associativity has been corrected and clarified. [perl #127391] The documentation for the C<\> referencing operator now explains the unusual context that it supplies to its operand. [perl #131061] =head3 L The means to disambiguate between code blocks and hash constructors, already documented in L, are now documented in L too. [perl #130958] =head3 L There is now a note that warnings generated by built-in functions are documented in L and L. [perl #116080] The documentation for the C operator no longer says that autovivification behaviour "may be fixed in a future release". We've determined that we're not going to change the default behaviour. [perl #127712] A couple of small details in the documentation for the C operator have been clarified. [perl #124428] The description of C<@INC> hooks in the documentation for C has been corrected to say that filter subroutines receive a useless first argument. [perl #115754] The documentation of C now explains what syntactically qualifies as a version number for its module version checking feature. =head3 L For each binary table or property, the documentation now includes which characters in the range C<\x00-\xFF> it matches, as well as a list of the first few ranges of code points matched above that. =head3 L The documentation about C methods has been corrected, updated, and revised, especially in regard to how they interact with exceptions. [perl #122753] =head3 L The documentation about set-id scripts has been updated and revised. [perl #74142] A section about using C to run Perl scripts has been added. =head3 L The examples in L have been made more portable in the way they exit, and the example that gets an exit code from the embedded Perl interpreter now gets it from the right place. The examples that pass a constructed argv to Perl now show the mandatory null C. =head3 L The description of the conditions under which C will be called has been clarified. [perl #131672] =head3 L The internal functions C and C are now documented. =head3 L The precise rules for identifying C branches are now stated. =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. =head2 New Diagnostics XXX Newly added diagnostic messages go under here, separated into New Errors and New Warnings =head3 New Errors =over 4 =item * LgotoE into a EgivenE block"> (F) A "goto" statement was executed to jump into the middle of a C block. You can't get there from here. See L. =back =head3 New Warnings =over 4 =item * L (W syntax) You used the old package separator, "'", in a variable named inside a double-quoted string; e.g., C<"In $name's house">. This is equivalent to C<"In $name::s house">. If you meant the former, put a backslash before the apostrophe (C<"In $name\'s house">). =back =head2 Changes to Existing Diagnostics XXX Changes (i.e. rewording) of diagnostic messages go here =over 4 =item * XXX Describe change here =item * The warning about useless use of a concatenation operator in void context is now generated for expressions with multiple concatenations, such as C<$a.$b.$c>, which used to mistakenly not warn. [perl #6997] =item * Warnings that a variable or subroutine "masks earlier declaration in same ...", or that an C variable has been redeclared, have been moved to a new warnings category "shadow". Previously they were in category "misc". =item * The deprecation warning from C saying that it doesn't accept arguments now states the Perl version in which the warning will be upgraded to an error. [perl #124349] =item * The L entry for the error regarding a set-id script has been expanded to make clear that the error is reporting a specific security vulnerability, and to advise how to fix it. =back =head1 Utility Changes XXX Changes to installed programs such as F and F go here. Most of these are built within the directory F. [ List utility changes as a =head2 entry for each utility and =item entries for each change Use L with program names to get proper documentation linking. ] =head2 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 an =item entry ]. =over 4 =item * XXX =item * Where an HTML version of the doucmentation is installed, the HTML documents now use relative links to refer to each other. Links from the index page of L to the individual section documents are now correct. [perl #110056] =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 summarizing, although the bugs that they represent may be covered elsewhere. XXX If there were no significant test changes, say this: Tests were added and changed to reflect the other additions and changes in this release. XXX If instead there were significant changes, say this: Tests were added and changed to reflect the other additions and changes in this release. Furthermore, these significant changes were made: [ List each test improvement as an =item entry ] =over 4 =item * XXX =back =head1 Platform Support XXX Any changes to platform support should be listed in the sections below. [ Within the sections, list each platform as an =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 Windows We now set C<$Config{libpth}> correctly for 64-bit builds using Visual C++ versions earlier than 14.1. =back =head1 Internal Changes XXX Changes which affect the interface available to C code go here. Other significant internal changes for future core maintainers should be noted as well. =over 4 =item * XS modules can now automatically get reentrant versions of system functions on threaded perls. By saying #define PERL_REENTRANT near the beginning of an C file, it will be compiled so that whatever reentrant functions perl knows about on that system will automatically and invisibly be used instead of the plain, non-reentrant versions. For example, if you write C in your code, on a system that has C all calls to the former will be translated invisibly into the latter. This does not happen except on threaded perls, as they aren't needed otherwise. Be aware that which functions have reentrant versions varies from system to system. =back =head1 Selected Bug Fixes XXX Important bug fixes in the core language are summarized here. Bug fixes in files in F and F are best summarized in L. [ List each fix as an =item entry ] =over 4 =item * XXX =item * Digits past the radix point in octal and binary floating point literals now have the correct weight on platforms where a floating point significand doesn't fit into an integer type. =item * C in a C or C block no longer permits the main program to run, and C in a C block no longer permits C blocks to run before exiting. [perl #2754] =item * The canonical truth value no longer has a spurious special meaning as a callable. It used to be a magic placeholder for a missing C or C method. It is now treated like any other string C<1>. [perl #126042] =item * The C built-in function now checks at compile time that it has only one parameter expression, and puts it in scalar context, thus ensuring that it doesn't corrupt the stack at runtime. [perl #4574] =item * C now performs correct reference counting when aliasing C<$a> and C<$b>, thus avoiding premature destruction and leakage of scalars if they are re-aliased during execution of the sort comparator. [perl #92264] =item * C with no operand, reversing C<$_> by default, is no longer in danger of corrupting the stack. [perl #132544] =item * Perl's own C no longer gets confused by attempts to allocate more than a gigabyte on a 64-bit platform. [perl #119829] =item * Stacked file test operators in a sort comparator expression no longer cause a crash. [perl #129347] =item * An identity C transformation on a reference is no longer mistaken for that reference for the purposes of deciding whether it can be assigned to. [perl #130578] =item * Lengthy hexadecimal, octal, or binary floating point literals no longer cause undefined behaviour when parsing digits that are of such low significance that they can't affect the floating point value. [perl #131894] =item * C and similar invocations no longer leak the file handle. [perl #115814] =item * Some convoluted kinds of regexp no longer cause an arithmetic overflow when compiled. [perl #131893] =item * The default typemap, by avoiding C, now no longer leaks when XSUBs return file handles (C or C). [perl #115814] =item * Creating a C block as an XS subroutine with a prototype no longer crashes because of the early freeing of the subroutine. =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. Unfixed platform specific bugs also go here. [ List each fix as an =item entry ] =over 4 =item * XXX =back =head1 Errata From Previous Releases =over 4 =item * XXX Add anything here that we forgot to add, or were mistaken about, in the perldelta of a previous release. =back =head1 Obituary XXX If any significant core contributor or member of the CPAN community has died, add a short obituary here. =head1 Acknowledgements XXX Generate this with: perl Porting/acknowledgements.pl v5.27.6..HEAD =head1 Reporting Bugs If you find what you think is a bug, you might check the perl bug database at L . There may also be information at L , 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 see L for details of how to report the issue. =head1 Give Thanks If you wish to thank the Perl 5 Porters for the work we had done in Perl 5, you can do so by running the C program: perlthanks This will send an email to the Perl 5 Porters list with your show of thanks. =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