=head1 NAME
-perldelta - what is new for perl v5.25.5
+[ 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 v5.25.9
=head1 DESCRIPTION
-This document describes differences between the 5.25.4 release and the 5.25.5
+This document describes differences between the 5.25.8 release and the 5.25.9
release.
-If you are upgrading from an earlier release such as 5.25.3, first read
-L<perl5254delta>, which describes differences between 5.25.3 and 5.25.4.
+If you are upgrading from an earlier release such as 5.25.7, first read
+L<perl5258delta>, which describes differences between 5.25.7 and 5.25.8.
+
+=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</Performance Enhancements> section.
+
+=head2 New regular expression modifier C</xx>
+
+Specifying two C<x> characters to modify a regular expression pattern
+does everything that a single one does, but additionally TAB and SPACE
+characters within a bracketed character class are generally ignored and
+can be added to improve readability, like
+S<C</[ ^ A-Z d-f p-x ]/xx>>. Details are at
+L<perlre/E<sol>x and E<sol>xx>.
=head1 Security
-=head2 "Escaped" colons and relative paths in PATH
+XXX Any security-related notices go here. In particular, any security
+vulnerabilities closed should be noted here rather than in the
+L</Selected Bug Fixes> 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</Reporting Bugs> below.
+
+[ List each incompatible change as a =head2 entry ]
+
+=head1 Deprecations
+
+=head2 String delimiters that aren't stand-alone graphemes are now
+deprecated
+
+In order for Perl to eventually allow string delimiters to be Unicode
+grapheme clusters (which look like a single character, but may be
+a sequence of several ones), we have to stop allowing a single char
+delimiter that isn't a grapheme by itself. These are unlikely to exist
+in actual code, as they would typically display as attached to the
+character in front of them.
+
+=head2 Module removals
-On Unix systems, Perl treats any relative paths in the PATH environment
-variable as tainted when starting a new process. Previously, it was
-allowing a backslash to escape a colon (unlike the OS), consequently
-allowing relative paths to be considered safe if the PATH was set to
-something like C</\:.>. The check has been fixed to treat C<.> as tainted
-in that example.
+XXX Remove this section if inapplicable.
+
+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 XXX
+
+XXX Note that deprecated modules should be listed here even if they are listed
+as an updated module in the L</Modules and Pragmata> 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 a =item entry ]
+
+=over 4
+
+=item *
+
+XXX
+
+=back
=head1 Modules and Pragmata
+XXX All changes to installed files in F<cpan/>, F<dist/>, F<ext/> and F<lib/>
+go here. If Module::CoreList is updated, generate an initial draft of the
+following sections using F<Porting/corelist-perldelta.pl>. A paragraph summary
+for important changes should then be added by hand. In an ideal world,
+dual-life modules would have a F<Changes> file that could be cribbed.
+
+[ Within each section, list entries as a =item entry ]
+
+=head2 New Modules and Pragmata
+
+=over 4
+
+=item *
+
+XXX
+
+=back
+
=head2 Updated Modules and Pragmata
=over 4
=item *
-L<Filter::Simple> has been upgraded from version 0.92 to 0.93.
+L<XXX> has been upgraded from version A.xx to B.yy.
+
+=item *
+
+L<re> has been upgraded from version 0.33 to 0.34;
-It no longer treats C<no MyFilter> immediately following C<use MyFilter> as
-end-of-file. [perl #107726]
+This adds support for the new L<C</xx>|perlre/E<sol>x and E<sol>xx>
+regular expression pattern modifier, and a change to the L<S<C<use re
+'strict'>>|re/'strict' mode> experimental feature. When S<C<re
+'strict'>> is enabled, a warning now will be generated for all
+unescaped uses of the two characters C<}> and C<]> in regular
+expression patterns (outside bracketed character classes) that are taken
+literally. This brings them more in line with the C<)> character which
+is always a metacharacter unless escaped. Being a metacharacter only
+sometimes, depending on action at a distance, can lead to silently
+having the pattern mean something quite different than was intended,
+which the S<C<re 'strict'>> mode is intended to minimize.
=item *
-L<Locale::Codes> has been upgraded from 3.39 to 3.40.
+L<B::Xref> has been upgraded from version 1.05 to 1.06.
=item *
-L<Module::CoreList> has been upgraded from version 5.20160820 to 5.20160920.
+L<Compress::Raw::Bzip2> has been upgraded from version 2.069 to 2.070.
=item *
-L<POSIX> has been upgraded from version 1.71 to 1.72.
+L<Compress::Raw::Zlib> has been upgraded from version 2.069 to 2.070.
=item *
-L<Sys::Syslog> has been upgraded from version 0.34_01 to 0.35.
+L<DB_File> has been upgraded from version 1.838 to 1.840.
=item *
-L<Test::Simple> has been upgraded from version 1.302052 to 1.302056.
+L<Devel::SelfStubber> has been upgraded from version 1.05 to 1.06.
=item *
-L<Thread::Semaphore> has been upgraded from 2.12 to 2.13.
+L<diagnostics> has been upgraded from version 1.35 to 1.36.
-Added the C<down_timed> method.
+=item *
+
+L<DynaLoader> has been upgraded from version 1.40 to 1.41.
+
+=item *
+
+L<Errno> has been upgraded from version 1.27 to 1.28.
+
+=item *
+
+L<ExtUtils::Embed> has been upgraded from version 1.33 to 1.34.
=item *
-L<XSLoader> has been upgraded from version 0.22 to 0.24.
+L<I18N::LangTags> has been upgraded from version 0.41 to 0.42.
+
+=item *
+
+L<lib> has been upgraded from version 0.63 to 0.64.
+
+=item *
+
+L<Module::CoreList> has been upgraded from version 5.20161220 to 5.20170120.
+
+=item *
+
+L<OS2::Process> has been upgraded from version 1.11 to 1.12.
+
+=item *
+
+L<perl5db.pl> has been upgraded from version 1.50 to 1.51.
+
+=item *
+
+L<Storable> has been upgraded from version 2.59 to 2.61.
+
+=item *
+
+L<Symbol> has been upgraded from version 1.07 to 1.08.
+
+=item *
+
+L<Term::ReadLine> has been upgraded from version 1.15 to 1.16.
+
+=item *
+
+L<Test> has been upgraded from version 1.29 to 1.30.
+
+=item *
+
+L<threads::shared> has been upgraded from version 1.52 to 1.53.
+
+=item *
+
+L<Unicode::UCD> has been upgraded from version 0.67 to 0.68.
+
+=item *
+
+L<VMS::DCLsym> has been upgraded from version 1.07 to 1.08.
+
+=item *
+
+L<XSLoader> has been upgraded from version 0.24 to 0.26.
+
+=back
+
+=head2 Removed Modules and Pragmata
+
+=over 4
+
+=item *
+
+XXX
=back
=head1 Documentation
+XXX Changes to files in F<pod/> go here. Consider grouping entries by
+file and be sure to link to the appropriate page, e.g. L<perlfunc>.
+
+=head2 New Documentation
+
+XXX Changes which create B<new> files in F<pod/> go here.
+
+=head3 L<XXX>
+
+XXX Description of the purpose of the new file here
+
=head2 Changes to Existing Documentation
-=head3 L<perlinterp>
+XXX Changes which significantly change existing files in F<pod/> go here.
+However, any changes to F<pod/perldiag.pod> should go in the L</Diagnostics>
+section.
+
+=head3 L<XXX>
=over 4
=item *
-L<perlinterp> has been expanded to give a more detailed example of how to
-hunt around in the parser for how a given operator is handled.
+XXX Description of the change here
=back
-=head1 Testing
+=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<perldiag>.
+
+XXX New or changed warnings emitted by the core's C<C> code go here. Also
+include any changes in L<perldiag> that reconcile it to the C<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 *
-F<t/re/regexp_nonull.t> has been added to test that the regular expression
-engine can handle scalars that do not have a null byte just past the end of
-the string.
+XXX L<message|perldiag/"message">
=back
-=head1 Platform Support
-
-=head2 Platform-Specific Notes
+=head3 New Warnings
=over 4
-=item VMS
+=item *
+
+XXX L<message|perldiag/"message">
+
+=back
+
+=head2 Changes to Existing Diagnostics
+
+As of Perl 5.25.9, all new deprecations will come with a version in
+which the feature will disappear. And with a few exceptions, most
+existing deprecations will state when they'll disappear. As such, most
+deprecation messages have changed.
=over 4
=item *
-The path separator for the C<PERL5LIB> and C<PERLLIB> environment entries is
-now a colon (C<:>) when running under a Unix shell. There is no change when
-running under DCL (it's still C<|>).
+Attribute "locked" is deprecated, and will disappear in Perl 5.28
=item *
-Remove some VMS-specific hacks from C<showlex.t>. These were added 15 years
-ago, and are no longer necessary for any VMS version now supported.
+Attribute "unique" is deprecated, and will disappear in Perl 5.28
-=back
+=item *
-=back
+"\c%c" is more clearly written simply as "%s". This will be a fatal error
+in Perl 5.28
-=over 4
+=item *
-=item Win32
+Constants from lexical variables potentially modified elsewhere are
+deprecated. This will not be allowed in Perl 5.32
-=over 4
+=item *
+
+Deprecated use of my() in false conditional. This will be a fatal error
+in Perl 5.30
=item *
-Tweaks for Win32 VC vs GCC detection makefile code. This fixes issue that CCHOME
-depends on CCTYPE, which in auto detect mode is set after CCHOME, so CCHOME uses
-the uninit CCTYPE var. Also fix else vs .ELSE in makefile.mk
+dump() better written as CORE::dump(). dump() will no longer be available
+in Perl 5.30
-=back
+=item *
-=back
+${^ENCODING} is no longer supported. Its use will be fatal in Perl 5.28
-=head1 Internal Changes
+=item *
-=over 4
+File::Glob::glob() will disappear in perl 5.30. Use File::Glob::bsd_glob()
+instead.
+
+=item *
+
+%s() is deprecated on :utf8 handles. This will be a fatal error in Perl 5.30
+
+=item *
+
+$* is no longer supported. Its use will be fatal in Perl 5.30
+
+=item *
+
+$* is no longer supported. Its use will be fatal in Perl 5.30
+
+=item *
+
+Opening dirhandle %s also as a file. This will be a fatal error in Perl 5.28
+
+=item *
+
+Opening filehandle %s also as a directory. This will be a fatal
+error in Perl 5.28
+
+=item *
+
+Setting $/ to a reference to %s as a form of slurp is deprecated,
+treating as undef. This will be fatal in Perl 5.28
+
+=item *
+
+Unescaped left brace in regex is deprecated here (and will be fatal
+in Perl 5.30), passed through in regex; marked by S<<-- HERE> in m/%s/
=item *
-Several macros and functions have been added to the public API for
-dealing with Unicode and UTF-8-encoded strings. See
-L<perlapi/Unicode Support>.
+Unknown charname '' is deprecated. Its use will be fatal in Perl 5.28
=item *
-Use C<my_strlcat()> in C<locale.c>. While C<strcat()> is safe in this context,
-some compilers were optimizing this to C<strcpy()> causing a porting test to
-fail that looks for unsafe code. Rather than fighting this, we just use
-C<my_strlcat()> instead.
+Use of bare << to mean <<"" is deprecated. Its use will be fatal in Perl 5.28
+
+=item *
+
+Use of code point 0x%s is deprecated; the permissible max is 0x%s.
+This will be fatal in Perl 5.28
+
+=item *
+
+Use of comma-less variable list is deprecated. Its use will be fatal
+in Perl 5.28
+
+=item *
+
+Use of inherited AUTOLOAD for non-method %s() is deprecated. This
+will be fatal in Perl 5.28
+
+=item *
+
+Use of strings with code points over 0xFF as arguments to %s operator
+is deprecated. This will be a fatal error in Perl 5.28
=back
-=head1 Selected Bug Fixes
+=head1 Utility Changes
+
+XXX Changes to installed programs such as F<perlbug> and F<xsubpp> go here.
+Most of these are built within the directory F<utils>.
+
+[ List utility changes as a =head2 entry for each utility and =item
+entries for each change
+Use L<XXX> with program names to get proper documentation linking. ]
+
+=head2 L<XXX>
=over 4
=item *
-Invalid assignments to a reference constructor (e.g., C<\eval=time>) could
-sometimes crash in addition to giving a syntax error. [perl #125679]
+XXX
+
+=back
+
+=head1 Configuration and Compilation
+
+XXX Changes to F<Configure>, F<installperl>, F<installman>, 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</Platform Support> section, instead.
+
+[ List changes as a =item entry ].
+
+=over 4
=item *
-The parser could sometimes crash if a bareword came after C<evalbytes>.
-[perl #129196]
+The C<dtrace> build process has further changes:
+
+=over
=item *
-Autoloading via a method call would warn erroneously ("Use of inherited
-AUTOLOAD for non-method") if there was a stub present in the package into
-which the invocant had been blessed. The warning is no longer emitted in
-such circumstances. [perl #47047]
+If the C<-xnolibs> is available, use that so a F<dtrace> perl can be
+built within a FreeBSD jail.
=item *
-A sub containing with a "forward" declaration with the same name (e.g.,
-C<sub c { sub c; }>) could sometimes crash or loop infinitely. [perl
-#129090]
+On systems that build a dtrace object file (FreeBSD, Solaris and
+SystemTap's dtrace emulation), copy the input objects to a separate
+directory and process them there, and use those objects in the link,
+since C<dtrace -G> also modifies these objects.
=item *
-The use of C<splice> on arrays with nonexistent elements could cause other
-operators to crash. [perl #129164]
+Add libelf to the build on FreeBSD 10.x, since dtrace adds references
+to libelf symbols.
=item *
-Fixed case where C<re_untuit_start> will overshoot the length of a utf8
-string. [perl #129012]
+Generate a dummy dtrace_main.o if C<dtrace -G> fails to build it. A
+default build on Solaris generates probes from the unused inline
+functions, while they don't on FreeBSD, which causes C<dtrace -G> to
+fail.
+
+=back
+
+[perl #130108]
=item *
-Handle C<CXt_SUBST> better in C<Perl_deb_stack_all>, previously it wasn't
-checking that the I<current> C<cx> is the right type, and instead was always
-checking the base C<cx> (effectively a noop). [perl #129029]
+You can now disable perl's use of the PERL_HASH_SEED and
+PERL_PERTURB_KEYS environment variables by configureing perl with
+C<-Accflags=NO_PERL_HASH_ENV>.
=item *
-Fixed two possible use-after-free bugs in C<Perl_yylex>. C<Perl_yylex>
-maintains up to two pointers into the parser buffer, one of which can
-become stale under the right conditions. [perl #129069]
+You can now disable perl's use of the PERL_HASH_SEED_DEBUG environment
+variable by configuring perl with
+C<-Accflags=-DNO_PERL_HASH_SEED_DEBUG>.
+
+=back
+
+=head1 Testing
+
+XXX Any significant changes to the testing of a freshly built perl should be
+listed here. Changes which create B<new> files in F<t/> go here as do any
+large changes to the testing harness (e.g. when parallel testing was added).
+Changes to existing files in F<t/> aren't worth summarizing, although the bugs
+that they represent may be covered elsewhere.
+
+[ List each test improvement as a =item entry ]
+
+=over 4
=item *
-Fixed a crash with C<s///l> where it thought it was dealing with UTF-8
-when it wasn't. [perl #129038]
+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 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<hints/>
+directories, or new subdirectories and F<README> 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</Modules and Pragmata> section.
+
+=over 4
+
+=item XXX-some-platform
+
+XXX
+
+=back
+
+=head1 Internal Changes
+
+XXX Changes which affect the interface available to C<XS> 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 *
-Fixed place where regex was not setting the syntax error correctly.
-[perl #129122]
+New versions of macros like C<isALPHA_utf8> and C<toLOWER_utf8> have
+been added, each with the
+suffix C<_safe>, like C<isSPACE_utf8_safe>. These take an extra
+parameter, giving an upper limit of how far into the string it is safe
+to read. Using the old versions could cause attempts to read beyond the
+end of the input buffer if the UTF-8 is not well-formed, and ther use
+now raises a deprecation warning. Details are at
+L<perlapi/Character classification>.
=item *
-The C<&.> operator (and the C<&> operator, when it treats its arguments as
-strings) were failing to append a trailing null byte if at least one string
-was marked as utf8 internally. Many code paths (system calls, regexp
-compilation) still expect there to be a null byte in the string buffer
-just past the end of the logical string. An assertion failure was the
-result. [perl #129287]
+Calling macros like C<isALPHA_utf8> on malformed UTF-8 have issued a
+deprecation warning since Perl v5.18. They now die.
+Similarly, macros like C<toLOWER_utf8> on malformed UTF-8 now die.
=item *
-Check C<pack_sockaddr_un()>'s return value because C<pack_sockaddr_un()>
-silently truncates the supplied path if it won't fit into the C<sun_path>
-member of C<sockaddr_un>. This may change in the future, but for now
-check the path in theC<sockaddr> matches the desired path, and skip if
-it doesn't. [perl #128095]
+Calling the functions C<utf8n_to_uvchr> and its derivatives, while
+passing a string length of 0 is now asserted against in DEBUGGING
+builds, and otherwise returns the Unicode REPLACEMENT CHARACTER. If
+you have nothing to decode, you shouldn't call the decode function.
=item *
-Make sure C<PL_oldoldbufptr> is preserved in C<scan_heredoc()>. In some
-cases this is used in building error messages. [perl #128988]
+The functions C<utf8n_to_uvchr> and its derivatives now return the
+Unicode REPLACEMENT CHARACTER if called with UTF-8 that has the overlong
+malformation, and that malformation is allowed by the input parameters.
+This malformation is where the UTF-8 looks valid syntactically, but
+there is a shorter sequence that yields the same code point. This has
+been forbidden since Unicode version 3.1.
=item *
-Check for null PL_curcop in IN_LC() [perl #129106]
+The functions C<utf8n_to_uvchr> and its derivatives now accept an input
+flag to allow the overflow malformation. This malformation is when the
+UTF-8 may be syntactically valid, but the code point it represents is
+not capable of being represented in the word length on the platform.
+What "allowed" means in this case is that the function doesn't return an
+error, and advances the parse pointer to beyond the UTF-8 in question,
+but it returns the Unicode REPLACEMENT CHARACTER as the value of the
+code point (since the real value is not representable).
+
+=back
+
+=head1 Selected Bug Fixes
+
+XXX Important bug fixes in the core language are summarized here. Bug fixes in
+files in F<ext/> and F<lib/> are best summarized in L</Modules and Pragmata>.
+
+[ List each fix as a =item entry ]
+
+=over 4
=item *
-Fixed the parser error handling for an 'C<:attr(foo>' that does not have
-an ending 'C<)>'.
+Under C<use utf8>, the entire Perl program is now checked that the UTF-8
+is wellformed. This resolves [perl #126310].
=item *
-Fix C<Perl_delimcpy()> to handle a backslash as last char, this
-actually fixed two bugs, [perl #129064] and [perl #129176].
+The range operator C<..> on strings now handles its arguments correctly when in
+the scope of the L<< C<unicode_strings>|feature/"The 'unicode_strings' feature" >>
+feature. The previous behaviour was sufficiently unexpected that we believe no
+correct program could have made use of it.
+
+=back
+
+=head1 Known Problems
+
+XXX Descriptions of platform agnostic bugs we know we can't fix go here. Any
+tests that had to be C<TODO>ed for the release would be noted here. Unfixed
+platform specific bugs also go here.
+
+[ List each fix as a =item entry ]
+
+=over 4
=item *
-[perl #129267] rework gv_fetchmethod_pvn_flags separator parsing to
-prevent possible string overrun with invalid len in gv.c
+XXX
=back
-=head1 Obituary
+=head1 Errata From Previous Releases
-Jon Portnoy (AVENJ), a prolific Perl author and admired Gentoo community
-member, has passed away on August 10, 2016. He will be remembered and
-missed by all those with which he came in contact and enriched with his
-intellect, wit, and spirit.
+=over 4
-=head1 Acknowledgements
+=item *
-Perl 5.25.5 represents approximately 4 weeks of development since Perl 5.25.4
-and contains approximately 67,000 lines of changes across 230 files from 25
-authors.
+XXX Add anything here that we forgot to add, or were mistaken about, in
+the perldelta of a previous release.
-Excluding auto-generated files, documentation and release tools, there were
-approximately 62,000 lines of changes to 160 .pm, .t, .c and .h files.
+=back
-Perl continues to flourish into its third decade thanks to a vibrant community
-of users and developers. The following people are known to have contributed the
-improvements that became Perl 5.25.5:
+=head1 Obituary
-Aaron Crane, Aristotle Pagaltzis, Chris 'BinGOs' Williams, Craig A. Berry,
-Dagfinn Ilmari Mannsåker, Dan Collins, Daniel Dragan, Dave Cross, David
-Mitchell, E. Choroba, Father Chrysostomos, James E Keenan, Jerry D. Hedden,
-Karl Williamson, Lukas Mai, Ricardo Signes, Rick Delaney, Sawyer X, Stevan
-Little, Steve Hay, Sullivan Beck, Theo Buehler, Tony Cook, Yaroslav Kuzmin,
-Yves Orton.
+XXX If any significant core contributor has died, we've added a short obituary
+here.
-The list above is almost certainly incomplete as it is automatically generated
-from version control history. In particular, it does not include the names of
-the (very much appreciated) contributors who reported issues to the Perl bug
-tracker.
+=head1 Acknowledgements
-Many of the changes included in this version originated in the CPAN modules
-included in Perl's core. We're grateful to the entire CPAN community for
-helping Perl to flourish.
+XXX Generate this with:
-For a more complete list of all of Perl's historical contributors, please see
-the F<AUTHORS> file in the Perl source distribution.
+ perl Porting/acknowledgements.pl v5.25.5..HEAD
=head1 Reporting Bugs
https://perl5.git.perl.org / perl5.git / blobdiff