Initial work for pod/erldelta for 5.23.5

Processed commits up to cb4547118517bc34243bbb938eeccfbd8016c64a.

Work that still needs to be done on perldelta before 5.23.5:
  -  New/Changed/Delete modules
  -  Acknowledgements
  -  And commits after cb4547118517bc34243bbb938eeccfbd8016c64a.
  -  Get the L<> link to work referring to a new diagnostic message.

1 files changed, 54 insertions, 227 deletions

diff --git a/pod/perldelta.pod b/pod/perldelta.pod
index f66a321252..43db260253 100644
--- a/pod/perldelta.pod
+++ b/pod/perldelta.pod
@@ -2,9 +2,6 @@
 
 =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 v5.23.5
 
 =head1 DESCRIPTION
@@ -15,81 +12,26 @@ release.
 If you are upgrading from an earlier release such as 5.23.3, first read
 L<perl5234delta>, which describes differences between 5.23.3 and 5.23.4.
 
-=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.
-
-[ List each enhancement as a =head2 entry ]
-
-=head1 Security
-
-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
-
-XXX Any deprecated features, syntax, modules etc. should be listed here.
-
-=head2 Module removals
-
-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.
+=over 4
 
-[ List each enhancement as a =item entry ]
+=item *
 
-=over 4
+Faster addition, subtraction and multiplication.
+
+Since 5.8.0, arithmetic became slower due to the need to support
+64-bit integers. To deal with 64-bit integers, a lot more corner
+cases need to be checked, which adds time. We now detect common
+cases where there is no need to check for those corner cases,
+and special-case them.
 
 =item *
 
-XXX
+Faster preincrement, predecrement, postincrement, postdecrement.
+
+By internally splitting the functions which handled multiple
+cases into different functions.
 
 =back
 
@@ -133,109 +75,40 @@ 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
-
-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 *
-
-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<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 *
 
-XXX L<message|perldiag/"message">
-
-=back
-
-=head3 New Warnings
-
-=over 4
-
-=item *
-
-XXX L<message|perldiag/"message">
+Sequence (?... not terminated in regex; marked by S<<-- HERE> in m/%s/
 
 =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<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 *
-
-XXX
+When running out of memory during an attempt the increase the stack
+size, previously, perl would die using the cryptic message 
+C<< panic: av_extend_guts() negative count (-9223372036854775681) >>.
+This has been fixed to show the prettier message:
+L<< Out of memory during stack extend|perldiag/"Out of memory during %s extend" >>
 
 =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 *
@@ -245,98 +118,55 @@ line options to override saved configuration.  This should eliminate confusion
 when command line options are ignored for no obvious reason.  C<-O> is now
 permitted, but ignored.
 
-=back
-
-=head1 Testing
+=item *
 
-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.
+Some filesystem stat symbols which were not used by the Perl core 
+were removed in an earlier commit. However, since these symbols
+turned out to be used by at least one CPAN module, these symbols
+have been restored.
 
-[ List each test improvement as a =item entry ]
+=item *
 
-=over 4
+C<< PPPort.so/PPPort.dll >> no longer get installed, as they are
+not used by C<< PPPort.pm >>, only by its test files.
 
 =item *
 
-XXX
+It is now possible to specify which compilation date to show on
+C<< perl -V >> output, by setting the macro C<< PERL_BUILD_DATE >>.
 
 =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.
+=head2 Platform-Specific Notes
 
 =over 4
 
-=item XXX-some-platform
-
-XXX
+=item Win32
 
-=back
+Win32 does now a parallel build with C++.
 
-=head2 Platform-Specific Notes
+=item Tru64
 
-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
+Workaround where Tru64 balks when prototypes are listed as
+C<< PERL_STATIC_INLINE >>, but where the test is build with
+C<< -DPERL_NO_INLINE_FUNCTIONS >>.
 
 =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 *
 
-XXX
+C<< sv_ref() >> is now part of the API.
 
 =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 *
@@ -355,40 +185,37 @@ L<perlrecharclass/Extended Bracketed Character Classes> caused panics
 instead of the proper error message.  This has now been fixed. [perl
 #126481]
 
-=back
-
-=head1 Known Problems
+=item *
 
-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.
+An earlier commit added a message when a quantifier in a regular
+expression was useless, but then caused the parser to skip it;
+this caused the surplus quantifier to be silently ignored, instead
+of throwing an error. This is now fixed [perl #126253]
 
-[ List each fix as a =item entry ]
+=item *
 
-=over 4
+The switch to building non-XS modules last in win32/makefile.mk (introduced
+by design as part of the changes to enable parallel building) caused the
+build of POSIX to break due to problems with the version module. This
+is now fixed.
 
 =item *
 
-XXX
+Improved parsing of hex float constants.
 
-=back
+=item *
 
-=head1 Errata From Previous Releases
-
-=over 4
+Fixed an issue with C<< pack >> where C<< pack "H" >> (and C<< pack "h" >>)
+could read past the source when given a non-utf8 source, and a utf8 target.
+[perl #126325]
 
 =item *
 
-XXX Add anything here that we forgot to add, or were mistaken about, in
-the perldelta of a previous release.
+Fixed several cases where perl would abort due to a segmentation fault,
+or a C-level assert. [perl #126615], [perl #126602], [perl #126193].
 
 =back
 
-=head1 Obituary
-
-XXX If any significant core contributor has died, we've added a short obituary
-here.
-
 =head1 Acknowledgements
 
 XXX Generate this with: