New perldelta for 5.33.7

11 files changed, 641 insertions, 192 deletions

diff --git a/MANIFEST b/MANIFEST
index 134a4ac362..d094c3e8c6 100644
--- a/MANIFEST
+++ b/MANIFEST
@@ -5233,6 +5233,7 @@ pod/perl5332delta.pod		Perl changes in version 5.33.2
 pod/perl5333delta.pod		Perl changes in version 5.33.3
 pod/perl5334delta.pod		Perl changes in version 5.33.4
 pod/perl5335delta.pod		Perl changes in version 5.33.5
+pod/perl5336delta.pod		Perl changes in version 5.33.6
 pod/perl561delta.pod		Perl changes in version 5.6.1
 pod/perl56delta.pod		Perl changes in version 5.6
 pod/perl581delta.pod		Perl changes in version 5.8.1
diff --git a/Makefile.SH b/Makefile.SH
index ba8d9bd19d..7ff2b144f6 100755
--- a/Makefile.SH
+++ b/Makefile.SH
@@ -589,7 +589,7 @@ esac
 
 $spitshell >>$Makefile <<'!NO!SUBS!'
 
-perltoc_pod_prereqs = extra.pods pod/perl5336delta.pod pod/perlapi.pod pod/perlintern.pod pod/perlmodlib.pod pod/perluniprops.pod
+perltoc_pod_prereqs = extra.pods pod/perl5337delta.pod pod/perlapi.pod pod/perlintern.pod pod/perlmodlib.pod pod/perluniprops.pod
 generated_pods = pod/perltoc.pod $(perltoc_pod_prereqs)
 generated_headers = uudmap.h bitcount.h mg_data.h
 
@@ -1153,9 +1153,9 @@ pod/perlintern.pod: $(MINIPERL_EXE) autodoc.pl embed.fnc
 pod/perlmodlib.pod: $(MINIPERL_EXE) pod/perlmodlib.PL MANIFEST
 	$(MINIPERL) pod/perlmodlib.PL -q
 
-pod/perl5336delta.pod: pod/perldelta.pod
-	$(RMS) pod/perl5336delta.pod
-	$(LNS) perldelta.pod pod/perl5336delta.pod
+pod/perl5337delta.pod: pod/perldelta.pod
+	$(RMS) pod/perl5337delta.pod
+	$(LNS) perldelta.pod pod/perl5337delta.pod
 
 extra.pods: $(MINIPERL_EXE)
 	-@test ! -f extra.pods || rm -f `cat extra.pods`
diff --git a/pod/.gitignore b/pod/.gitignore
index 5ff5f607bc..c8d7ad839d 100644
--- a/pod/.gitignore
+++ b/pod/.gitignore
@@ -48,7 +48,7 @@
 /roffitall
 
 # generated
-/perl5336delta.pod
+/perl5337delta.pod
 /perlapi.pod
 /perlintern.pod
 /perlmodlib.pod
diff --git a/pod/perl.pod b/pod/perl.pod
index b9503d53fe..73877f1507 100644
--- a/pod/perl.pod
+++ b/pod/perl.pod
@@ -184,6 +184,7 @@ aux h2ph h2xs perlbug pl2pm pod2html pod2man splain xsubpp
 
     perlhist		Perl history records
     perldelta		Perl changes since previous version
+    perl5336delta	Perl changes in version 5.33.6
     perl5335delta	Perl changes in version 5.33.5
     perl5334delta	Perl changes in version 5.33.4
     perl5333delta	Perl changes in version 5.33.3
diff --git a/pod/perl5336delta.pod b/pod/perl5336delta.pod
new file mode 100644
index 0000000000..9d5a2f9f79
--- /dev/null
+++ b/pod/perl5336delta.pod
@@ -0,0 +1,400 @@
+=encoding utf8
+
+=head1 NAME
+
+perl5336delta - what is new for perl v5.33.6
+
+=head1 DESCRIPTION
+
+This document describes differences between the 5.33.5 release and the
+5.33.6 release.
+
+If you are upgrading from an earlier release such as 5.33.4, first read
+L<perl5335delta>, which describes differences between 5.33.4 and 5.33.5.
+
+=head1 Core Enhancements
+
+=head2 C<qr/{,n}/> is now accepted
+
+An empty lower bound is now accepted for regular expression quantifiers,
+like C<{,3}>.
+
+=head2 Blanks freely allowed within but adjacent to curly braces
+
+(in double-quotish contexts and regular expression patterns)
+
+This means you can write things like S<C<\x{ FFFC }>> if you like.  This
+applies to all such constructs, namely C<\b{}>, C<\g{}>, C<\k{}>,
+C<\N{}>, C<\o{}>, and C<\x{}>; as well as the regular expression
+quantifier C<{I<m>,I<n>}>.  C<\p{}> and C<\P{}> retain their
+already-existing, even looser, rules mandated by the Unicode standard
+(see L<perluniprops/Properties accessible through \p{} and \P{}>).
+
+This ability is in effect regardless of the presence of the C</x>
+regular expression pattern modifier.
+
+Additionally, the comma in a regular expression braced quantifier may
+have blanks (tabs or spaces) before and/or after the comma, like
+S<C<qr/a{ 5, 7 }/>>.
+
+=head1 Modules and Pragmata
+
+=head2 Updated Modules and Pragmata
+
+=over 4
+
+=item *
+
+L<Carp> has been upgraded from version 1.51 to 1.52.
+
+=item *
+
+L<Compress::Raw::Bzip2> has been upgraded from version 2.096 to 2.100.
+
+=item *
+
+L<Compress::Raw::Zlib> has been upgraded from version 2.096 to 2.100.
+
+=item *
+
+L<DynaLoader> has been upgraded from version 1.49 to 1.50.
+
+=item *
+
+L<ExtUtils::MakeMaker> has been upgraded from version 7.56 to 7.58.
+
+=item *
+
+L<ExtUtils::Manifest> has been upgraded from version 1.72 to 1.73.
+
+=item *
+
+L<feature> has been upgraded from version 1.61 to 1.62.
+
+Added the default enabled C<bareword_filehandles> feature.
+
+=item *
+
+L<GDBM_File> has been upgraded from version 1.18 to 1.19.
+
+New functions and compatibility for newer versions of GDBM.
+[L<GH #18435|https://github.com/Perl/perl5/pull/18435>]
+
+=item *
+
+L<IO> has been upgraded from version 1.44 to 1.45.
+
+IO::Socket now stores error messages in C<$IO::Socket::errstr>, in
+addition to in C<$@>.
+
+=item *
+
+IO-Compress has been upgraded from version 2.096 to 2.100.
+
+=item *
+
+libnet has been upgraded from version 3.12 to 3.13.
+
+=item *
+
+L<Module::CoreList> has been upgraded from version 5.20201220 to 5.20210120.
+
+=item *
+
+L<POSIX> has been upgraded from version 1.96 to 1.97.
+
+POSIX::signbit() behaviour has been improved.
+[L<GH #18441|https://github.com/Perl/perl5/pull/18441>]
+
+Documentation for C<asctime> clarifies that the result is always in English.
+(Use C<strftime> for a localized result.)
+
+=item *
+
+L<Socket> has been upgraded from version 2.030 to 2.031.
+
+=item *
+
+L<warnings> has been upgraded from version 1.49 to 1.50.
+
+=item *
+
+L<XS::APItest> has been upgraded from version 1.14 to 1.15.
+
+=back
+
+=head1 Documentation
+
+=head2 New Documentation
+
+=head3 L<perlgov>
+
+This document describes the goals, scope, system, and rules for Perl's new
+governance model.
+
+Other pod files, most notably L<perlpolicy>, were amended to reflect
+its adoption.
+
+=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, open an issue
+at L<https://github.com/Perl/perl5/issues>.
+
+Additionally, the following selected changes have been made:
+
+=head3 L<perlcommunity>
+
+=over 4
+
+=item *
+
+The freenode IRC URL has been updated.
+
+=back
+
+=head3 L<perlfunc>
+
+=over 4
+
+=item *
+
+The L<localtime|perlfunc/localtime> entry has been improved and now
+also states that the result of the function is always in English.
+
+=back
+
+=head3 L<perlsyn>
+
+=over 4
+
+=item *
+
+A new example shows how a lexical C<my> variable can be declared
+during the initialization of a C<for> loop.
+
+=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>.
+
+=head2 New Diagnostics
+
+=head3 New Errors
+
+=over 4
+
+=item *
+
+L<Bareword filehandle "%s" not allowed under 'no feature "bareword_filehandles"'|perldiag/"Bareword filehandle "%s" not allowed under 'no feature "bareword_filehandles"'">
+
+This accompanies the new L<bareword_filehandles|feature/"The 'bareword_filehandles' feature."> feature.
+
+=back
+
+=head2 Changes to Existing Diagnostics
+
+=over 4
+
+=item *
+
+L<Too few arguments for subroutine '%s' (got %d; expected %d)|perldiag/"Too few arguments for subroutine '%s' (got %d; expected %d)">
+
+Subroutine argument-count mismatch errors now include the number of
+given and expected arguments.
+
+=item *
+
+L<Too many arguments for subroutine '%s' (got %d; expected %d)|perldiag/"Too many arguments for subroutine '%s' (got %d; expected %d)">
+
+Subroutine argument-count mismatch errors now include the number of
+given and expected arguments.
+
+=item *
+
+L<Lost precision when %s %f by 1|perldiag/"Lost precision when %s %f by 1">
+
+This warning was only issued for positive too-large values when 
+incrementing, and only for negative ones when decrementing.
+It is now issued for both positive or negative too-large values.
+[L<GH #18333|https://github.com/Perl/perl5/issues/18333>]
+
+=back
+
+=head1 Configuration and Compilation
+
+=over 4
+
+=item * Configure
+
+A new probe checks for buggy libc implementations of the C<gcvt>/C<qgcvt>
+functions.
+[L<GH #18170|https://github.com/Perl/perl5/issues/18170>]
+
+=back
+
+=head1 Testing
+
+Tests were added and changed to reflect the other additions and
+changes in this release.  Furthermore, these significant changes were
+made:
+
+=over 4
+
+=item *
+
+F<t/re/opt.t> was added, providing a test harness for regexp optimization.
+[L<GH #18213|https://github.com/Perl/perl5/pull/18213>]
+
+=item *
+
+A workaround for CPAN distributions needing dot in C<@INC> has been removed
+[L<GH #18394|https://github.com/Perl/perl5/pull/18394>].
+All distributions that previously required the workaround have now been
+adapted.
+
+=back
+
+=head1 Platform Support
+
+=head2 Platform-Specific Notes
+
+=over 4
+
+=item Mac OS X
+
+A number of system libraries no longer exist as actual files on Big Sur,
+even though C<dlopen> will pretend they do, so now we fall back to C<dlopen>
+if a library file can not be found.
+[L<GH #18407|https://github.com/Perl/perl5/issues/18407>]
+
+=item MS Windows
+
+perl can now be built with C<USE_QUADMATH> on MS Windows using
+(32-bit and 64-bit) mingw-w64 ports of gcc.
+[L<GH #18465|https://github.com/Perl/perl5/pull/18465>]
+
+The F<pl2bat.pl> utility now needs to C<use ExtUtils::PL2Bat>. This could
+cause failures in parallel builds.
+
+=back
+
+=head1 Selected Bug Fixes
+
+=over 4
+
+=item *
+
+Skip trying to constant fold an incomplete op tree
+[L<GH #18380|https://github.com/Perl/perl5/issues/18380>]
+
+Constant folding of chained comparison op trees could fail under certain
+conditions, causing perl to crash. As a quick fix, constant folding is
+now skipped for such op trees. This also addresses
+[L<GH #17917|https://github.com/Perl/perl5/issues/17917>].
+
+=item *
+
+%g formatting broken on Ubuntu-18.04, NVSIZE == 8
+[L<GH #18170|https://github.com/Perl/perl5/issues/18170>]
+
+Buggy libc implementations of the C<gcvt> and C<qgcvt> functions
+caused C<(s)printf> to incorrectly truncate C<%g> formatted numbers.
+A new Configure probe now checks for this, with the result that the libc
+C<sprintf> will be used in place of C<gcvt> and C<qgcvt>.
+
+Tests added as part of this fix also revealed related problems in
+some Windows builds. The makefiles for MINGW builds on Windows have
+thus been adjusted to use USE_MINGW_ANSI_STDIO by default, ensuring
+that they also provide correct C<(s)printf> formatting of numbers.
+
+=item *
+
+op.c: croak on "my $_" when "use utf8" is in effect
+[L<GH #18449|https://github.com/Perl/perl5/issues/18449>]
+
+The lexical topic feature experiment was removed in Perl v5.24 and
+declaring C<my $_> became a compile time error. However, it was previously
+still possible to make this declaration if C<use utf8> was in effect.
+
+=item *
+
+regexec.c: Fix assertion failure
+[L<GH #18451|https://github.com/Perl/perl5/issues/18451>]
+
+Fuzzing triggered an assertion failure in the regexp engine when too many
+characters were copied into a buffer.
+
+=back
+
+=head1 Acknowledgements
+
+Perl 5.33.6 represents approximately 4 weeks of development since Perl
+5.33.5 and contains approximately 96,000 lines of changes across 450 files
+from 26 authors.
+
+Excluding auto-generated files, documentation and release tools, there were
+approximately 85,000 lines of changes to 320 .pm, .t, .c and .h files.
+
+Perl continues to flourish into its fourth decade thanks to a vibrant
+community of users and developers. The following people are known to have
+contributed the improvements that became Perl 5.33.6:
+
+Branislav Zahradník, Chris 'BinGOs' Williams, Craig A. Berry, Dan Book,
+Daniel Böhmer, Daniel Laügt, Felipe Gasper, Hugo van der Sanden, James E
+Keenan, Kang-min Liu, Karen Etheridge, Karl Williamson, Leon Timmermans, Max
+Maischein, Michael G Schwern, Paul Evans, Ricardo Signes, Richard Leach,
+Sawyer X, Sergey Poznyakoff, Sisyphus, Steve Hay, TAKAI Kousuke, Tomasz
+Konojacki, Tom Hukins, Tony Cook.
+
+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.
+
+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.
+
+For a more complete list of all of Perl's historical contributors, please
+see the F<AUTHORS> file in the Perl source distribution.
+
+=head1 Reporting Bugs
+
+If you find what you think is a bug, you might check the perl bug database
+at L<https://github.com/Perl/perl5/issues>.  There may also be information at
+L<http://www.perl.org/>, the Perl Home Page.
+
+If you believe you have an unreported bug, please open an issue at
+L<https://github.com/Perl/perl5/issues>.  Be sure to trim your bug down to a
+tiny but sufficient test case.
+
+If the bug you are reporting has security implications which make it
+inappropriate to send to a public issue tracker, then see
+L<perlsec/SECURITY VULNERABILITY CONTACT INFORMATION>
+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<perlthanks> program:
+
+    perlthanks
+
+This will send an email to the Perl 5 Porters list with your show of thanks.
+
+=head1 SEE ALSO
+
+The F<Changes> file for an explanation of how to view exhaustive details on
+what changed.
+
+The F<INSTALL> file for how to build Perl.
+
+The F<README> file for general stuff.
+
+The F<Artistic> and F<Copying> files for copyright information.
+
+=cut
diff --git a/pod/perldelta.pod b/pod/perldelta.pod
index 0ee662a8e8..b2f4d8bbb0 100644
--- a/pod/perldelta.pod
+++ b/pod/perldelta.pod
@@ -2,138 +2,157 @@
 
 =head1 NAME
 
-perldelta - what is new for perl v5.33.6
+[ 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 v5.33.7
 
 =head1 DESCRIPTION
 
-This document describes differences between the 5.33.5 release and the
-5.33.6 release.
+This document describes differences between the 5.33.6 release and the 5.33.7
+release.
 
-If you are upgrading from an earlier release such as 5.33.4, first read
-L<perl5335delta>, which describes differences between 5.33.4 and 5.33.5.
+If you are upgrading from an earlier release such as 5.33.5, first read
+L<perl5336delta>, which describes differences between 5.33.5 and 5.33.6.
 
-=head1 Core Enhancements
+=head1 Notice
 
-=head2 C<qr/{,n}/> is now accepted
+XXX Any important notices here
 
-An empty lower bound is now accepted for regular expression quantifiers,
-like C<{,3}>.
+=head1 Core Enhancements
 
-=head2 Blanks freely allowed within but adjacent to curly braces
+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.
 
-(in double-quotish contexts and regular expression patterns)
+[ List each enhancement as a =head2 entry ]
 
-This means you can write things like S<C<\x{ FFFC }>> if you like.  This
-applies to all such constructs, namely C<\b{}>, C<\g{}>, C<\k{}>,
-C<\N{}>, C<\o{}>, and C<\x{}>; as well as the regular expression
-quantifier C<{I<m>,I<n>}>.  C<\p{}> and C<\P{}> retain their
-already-existing, even looser, rules mandated by the Unicode standard
-(see L<perluniprops/Properties accessible through \p{} and \P{}>).
+=head1 Security
 
-This ability is in effect regardless of the presence of the C</x>
-regular expression pattern modifier.
+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.
 
-Additionally, the comma in a regular expression braced quantifier may
-have blanks (tabs or spaces) before and/or after the comma, like
-S<C<qr/a{ 5, 7 }/>>.
+[ List each security issue as a =head2 entry ]
 
-=head1 Modules and Pragmata
+=head1 Incompatible Changes
 
-=head2 Updated Modules and Pragmata
-
-=over 4
+XXX For a release on a stable branch, this section aspires to be:
 
-=item *
+    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.
 
-L<Carp> has been upgraded from version 1.51 to 1.52.
+[ List each incompatible change as a =head2 entry ]
 
-=item *
+=head1 Deprecations
 
-L<Compress::Raw::Bzip2> has been upgraded from version 2.096 to 2.100.
+XXX Any deprecated features, syntax, modules etc. should be listed here.
 
-=item *
+=head2 Module removals
 
-L<Compress::Raw::Zlib> has been upgraded from version 2.096 to 2.100.
+XXX Remove this section if not applicable.
 
-=item *
+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.
 
-L<DynaLoader> has been upgraded from version 1.49 to 1.50.
+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.
 
-=item *
+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.
 
-L<ExtUtils::MakeMaker> has been upgraded from version 7.56 to 7.58.
+=over
 
-=item *
+=item XXX
 
-L<ExtUtils::Manifest> has been upgraded from version 1.72 to 1.73.
+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.
 
-=item *
+=back
 
-L<feature> has been upgraded from version 1.61 to 1.62.
+[ List each other deprecation as a =head2 entry ]
 
-Added the default enabled C<bareword_filehandles> feature.
+=head1 Performance Enhancements
 
-=item *
+XXX Changes which enhance performance without changing behaviour go here.
+There may well be none in a stable release.
 
-L<GDBM_File> has been upgraded from version 1.18 to 1.19.
+[ List each enhancement as an =item entry ]
 
-New functions and compatibility for newer versions of GDBM.
-[L<GH #18435|https://github.com/Perl/perl5/pull/18435>]
+=over 4
 
 =item *
 
-L<IO> has been upgraded from version 1.44 to 1.45.
+XXX
 
-IO::Socket now stores error messages in C<$IO::Socket::errstr>, in
-addition to in C<$@>.
+=back
 
-=item *
+=head1 Modules and Pragmata
 
-IO-Compress has been upgraded from version 2.096 to 2.100.
+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.
 
-=item *
+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.)
 
-libnet has been upgraded from version 3.12 to 3.13.
+[ Within each section, list entries as an =item entry ]
 
-=item *
+=head2 New Modules and Pragmata
 
-L<Module::CoreList> has been upgraded from version 5.20201220 to 5.20210120.
+=over 4
 
 =item *
 
-L<POSIX> has been upgraded from version 1.96 to 1.97.
+XXX Remove this section if not applicable.
+
+=back
 
-POSIX::signbit() behaviour has been improved.
-[L<GH #18441|https://github.com/Perl/perl5/pull/18441>]
+=head2 Updated Modules and Pragmata
 
-Documentation for C<asctime> clarifies that the result is always in English.
-(Use C<strftime> for a localized result.)
+=over 4
 
 =item *
 
-L<Socket> has been upgraded from version 2.030 to 2.031.
+L<XXX> has been upgraded from version A.xx to B.yy.
 
-=item *
+If there was something important to note about this change, include that here.
+
+=back
 
-L<warnings> has been upgraded from version 1.49 to 1.50.
+=head2 Removed Modules and Pragmata
+
+=over 4
 
 =item *
 
-L<XS::APItest> has been upgraded from version 1.14 to 1.15.
+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
 
-=head3 L<perlgov>
+XXX Changes which create B<new> files in F<pod/> go here.
 
-This document describes the goals, scope, system, and rules for Perl's new
-governance model.
+=head3 L<XXX>
 
-Other pod files, most notably L<perlpolicy>, were amended to reflect
-its adoption.
+XXX Description of the purpose of the new file here
 
 =head2 Changes to Existing Documentation
 
@@ -141,226 +160,250 @@ We have attempted to update the documentation to reflect the changes
 listed in this document.  If you find any we have missed, open an issue
 at L<https://github.com/Perl/perl5/issues>.
 
+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.
+
 Additionally, the following selected changes have been made:
 
-=head3 L<perlcommunity>
+=head3 L<XXX>
 
 =over 4
 
 =item *
 
-The freenode IRC URL has been updated.
+XXX Description of the change here
 
 =back
 
-=head3 L<perlfunc>
+=head1 Diagnostics
 
-=over 4
+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>.
 
-=item *
+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.
 
-The L<localtime|perlfunc/localtime> entry has been improved and now
-also states that the result of the function is always in English.
+=head2 New Diagnostics
 
-=back
+XXX Newly added diagnostic messages go under here, separated into New Errors
+and New Warnings
 
-=head3 L<perlsyn>
+=head3 New Errors
 
 =over 4
 
 =item *
 
-A new example shows how a lexical C<my> variable can be declared
-during the initialization of a C<for> loop.
+XXX L<message|perldiag/"message">
 
 =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>.
-
-=head2 New Diagnostics
-
-=head3 New Errors
+=head3 New Warnings
 
 =over 4
 
 =item *
 
-L<Bareword filehandle "%s" not allowed under 'no feature|perldiag/"Bareword filehandle "%s" not allowed under 'no feature "bareword_filehandles"'">
-
-This accompanies the new L<bareword_filehandles|feature/"The 'bareword_filehandles' feature."> feature.
+XXX L<message|perldiag/"message">
 
 =back
 
 =head2 Changes to Existing Diagnostics
 
+XXX Changes (i.e. rewording) of diagnostic messages go here
+
 =over 4
 
 =item *
 
-L<Too few arguments for subroutine '%s' (got %d; expected %d)|perldiag/"Too few arguments for subroutine '%s' (got %d; expected %d)">
+XXX Describe change here
 
-Subroutine argument-count mismatch errors now include the number of
-given and expected arguments.
+=back
 
-=item *
+=head1 Utility Changes
 
-L<Too many arguments for subroutine '%s' (got %d; expected %d)|perldiag/"Too many arguments for subroutine '%s' (got %d; expected %d)">
+XXX Changes to installed programs such as F<perldoc> and F<xsubpp> go here.
+Most of these are built within the directory F<utils>.
 
-Subroutine argument-count mismatch errors now include the number of
-given and expected arguments.
+[ 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. ]
 
-=item *
+=head2 L<XXX>
 
-L<Lost precision when %s %f by 1|perldiag/"Lost precision when %s %f by 1">
+=over 4
 
-This warning was only issued for positive too-large values when 
-incrementing, and only for negative ones when decrementing.
-It is now issued for both positive or negative too-large values.
-[L<GH #18333|https://github.com/Perl/perl5/issues/18333>]
+=item *
+
+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 an =item entry ].
+
 =over 4
 
-=item * Configure
+=item *
 
-A new probe checks for buggy libc implementations of the C<gcvt>/C<qgcvt>
-functions.
-[L<GH #18170|https://github.com/Perl/perl5/issues/18170>]
+XXX
 
 =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.
+
+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 *
 
-F<t/re/opt.t> was added, providing a test harness for regexp optimization.
-[L<GH #18213|https://github.com/Perl/perl5/pull/18213>]
+XXX
 
-=item *
+=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
 
-A workaround for CPAN distributions needing dot in C<@INC> has been removed
-[L<GH #18394|https://github.com/Perl/perl5/pull/18394>].
-All distributions that previously required the workaround have now been
-adapted.
+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
 
-=head1 Platform Support
+=head2 Discontinued Platforms
 
-=head2 Platform-Specific Notes
+XXX List any platforms that this version of perl no longer compiles on.
 
 =over 4
 
-=item Mac OS X
+=item XXX-some-platform
 
-A number of system libraries no longer exist as actual files on Big Sur,
-even though C<dlopen> will pretend they do, so now we fall back to C<dlopen>
-if a library file can not be found.
-[L<GH #18407|https://github.com/Perl/perl5/issues/18407>]
+XXX
 
-=item MS Windows
+=back
+
+=head2 Platform-Specific Notes
 
-perl can now be built with C<USE_QUADMATH> on MS Windows using
-(32-bit and 64-bit) mingw-w64 ports of gcc.
-[L<GH #18465|https://github.com/Perl/perl5/pull/18465>]
+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.
 
-The F<pl2bat.pl> utility now needs to C<use ExtUtils::PL2Bat>. This could
-cause failures in parallel builds.
+=over 4
+
+=item XXX-some-platform
+
+XXX
 
 =back
 
-=head1 Selected Bug Fixes
+=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 an =item entry ]
 
 =over 4
 
 =item *
 
-Skip trying to constant fold an incomplete op tree
-[L<GH #18380|https://github.com/Perl/perl5/issues/18380>]
+XXX
 
-Constant folding of chained comparison op trees could fail under certain
-conditions, causing perl to crash. As a quick fix, constant folding is
-now skipped for such op trees. This also addresses
-[L<GH #17917|https://github.com/Perl/perl5/issues/17917>].
+=back
 
-=item *
+=head1 Selected Bug Fixes
 
-%g formatting broken on Ubuntu-18.04, NVSIZE == 8
-[L<GH #18170|https://github.com/Perl/perl5/issues/18170>]
+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>.
 
-Buggy libc implementations of the C<gcvt> and C<qgcvt> functions
-caused C<(s)printf> to incorrectly truncate C<%g> formatted numbers.
-A new Configure probe now checks for this, with the result that the libc
-C<sprintf> will be used in place of C<gcvt> and C<qgcvt>.
+[ List each fix as an =item entry ]
 
-Tests added as part of this fix also revealed related problems in
-some Windows builds. The makefiles for MINGW builds on Windows have
-thus been adjusted to use USE_MINGW_ANSI_STDIO by default, ensuring
-that they also provide correct C<(s)printf> formatting of numbers.
+=over 4
 
 =item *
 
-op.c: croak on "my $_" when "use utf8" is in effect
-[L<GH #18449|https://github.com/Perl/perl5/issues/18449>]
+XXX
 
-The lexical topic feature experiment was removed in Perl v5.24 and
-declaring C<my $_> became a compile time error. However, it was previously
-still possible to make this declaration if C<use utf8> was in effect.
+=back
 
-=item *
+=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.
 
-regexec.c: Fix assertion failure
-[L<GH #18451|https://github.com/Perl/perl5/issues/18451>]
+[ List each fix as an =item entry ]
 
-Fuzzing triggered an assertion failure in the regexp engine when too many
-characters were copied into a buffer.
+=over 4
+
+=item *
+
+XXX
 
 =back
 
-=head1 Acknowledgements
+=head1 Errata From Previous Releases
 
-Perl 5.33.6 represents approximately 4 weeks of development since Perl
-5.33.5 and contains approximately 96,000 lines of changes across 450 files
-from 26 authors.
+=over 4
+
+=item *
 
-Excluding auto-generated files, documentation and release tools, there were
-approximately 85,000 lines of changes to 320 .pm, .t, .c and .h files.
+XXX Add anything here that we forgot to add, or were mistaken about, in
+the perldelta of a previous release.
 
-Perl continues to flourish into its fourth decade thanks to a vibrant
-community of users and developers. The following people are known to have
-contributed the improvements that became Perl 5.33.6:
+=back
+
+=head1 Obituary
 
-Branislav Zahradník, Chris 'BinGOs' Williams, Craig A. Berry, Dan Book,
-Daniel Böhmer, Daniel Laügt, Felipe Gasper, Hugo van der Sanden, James E
-Keenan, Kang-min Liu, Karen Etheridge, Karl Williamson, Leon Timmermans, Max
-Maischein, Michael G Schwern, Paul Evans, Ricardo Signes, Richard Leach,
-Sawyer X, Sergey Poznyakoff, Sisyphus, Steve Hay, TAKAI Kousuke, Tomasz
-Konojacki, Tom Hukins, Tony Cook.
+XXX If any significant core contributor or member of the CPAN community has
+died, add 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 v5.33.6..HEAD
 
 =head1 Reporting Bugs
 
diff --git a/vms/descrip_mms.template b/vms/descrip_mms.template
index 925d2c34ca..126d741a09 100644
--- a/vms/descrip_mms.template
+++ b/vms/descrip_mms.template
@@ -313,7 +313,7 @@ utils : $(utils1) $(utils2) $(utils3) $(utils4) $(utils5)
 extra.pods : miniperl
 	@ @extra_pods.com
 
-PERLDELTA_CURRENT = [.pod]perl5336delta.pod
+PERLDELTA_CURRENT = [.pod]perl5337delta.pod
 
 $(PERLDELTA_CURRENT) : [.pod]perldelta.pod
 	Copy/NoConfirm/Log $(MMS$SOURCE) $(PERLDELTA_CURRENT)
diff --git a/win32/GNUmakefile b/win32/GNUmakefile
index af0fdf4504..98510dbe66 100644
--- a/win32/GNUmakefile
+++ b/win32/GNUmakefile
@@ -1776,7 +1776,7 @@ utils: $(HAVEMINIPERL) ..\utils\Makefile
 	copy ..\README.tw       ..\pod\perltw.pod
 	copy ..\README.vos      ..\pod\perlvos.pod
 	copy ..\README.win32    ..\pod\perlwin32.pod
-	copy ..\pod\perldelta.pod ..\pod\perl5336delta.pod
+	copy ..\pod\perldelta.pod ..\pod\perl5337delta.pod
 	$(MINIPERL) -I..\lib $(PL2BAT) $(UTILS)
 	$(MINIPERL) -I..\lib ..\autodoc.pl ..
 	$(MINIPERL) -I..\lib ..\pod\perlmodlib.PL -q ..
@@ -1874,7 +1874,7 @@ distclean: realclean
 	-if exist $(LIBDIR)\Win32API rmdir /s /q $(LIBDIR)\Win32API
 	-if exist $(LIBDIR)\XS rmdir /s /q $(LIBDIR)\XS
 	-cd $(PODDIR) && del /f *.html *.bat roffitall \
-	    perl5336delta.pod perlaix.pod perlamiga.pod perlandroid.pod \
+	    perl5337delta.pod perlaix.pod perlamiga.pod perlandroid.pod \
 	    perlapi.pod perlbs2000.pod perlcn.pod perlcygwin.pod \
 	    perldos.pod perlfreebsd.pod perlhaiku.pod perlhpux.pod \
 	    perlhurd.pod perlintern.pod perlirix.pod perljp.pod perlko.pod \
diff --git a/win32/Makefile b/win32/Makefile
index 4986f0b230..7f4ebccd9d 100644
--- a/win32/Makefile
+++ b/win32/Makefile
@@ -1240,7 +1240,7 @@ utils: $(PERLEXE) ..\utils\Makefile
 	copy ..\README.tw       ..\pod\perltw.pod
 	copy ..\README.vos      ..\pod\perlvos.pod
 	copy ..\README.win32    ..\pod\perlwin32.pod
-	copy ..\pod\perldelta.pod ..\pod\perl5336delta.pod
+	copy ..\pod\perldelta.pod ..\pod\perl5337delta.pod
 	cd ..\win32
 	$(PERLEXE) $(PL2BAT) $(UTILS)
 	$(MINIPERL) -I..\lib ..\autodoc.pl ..
@@ -1339,7 +1339,7 @@ distclean: realclean
 	-if exist $(LIBDIR)\Win32API rmdir /s /q $(LIBDIR)\Win32API
 	-if exist $(LIBDIR)\XS rmdir /s /q $(LIBDIR)\XS
 	-cd $(PODDIR) && del /f *.html *.bat roffitall \
-	    perl5336delta.pod perlaix.pod perlamiga.pod perlandroid.pod \
+	    perl5337delta.pod perlaix.pod perlamiga.pod perlandroid.pod \
 	    perlapi.pod perlbs2000.pod perlcn.pod perlcygwin.pod \
 	    perldos.pod perlfreebsd.pod perlhaiku.pod perlhpux.pod \
 	    perlhurd.pod perlintern.pod perlirix.pod perljp.pod perlko.pod \
diff --git a/win32/makefile.mk b/win32/makefile.mk
index 1e2a39c13c..43b457d593 100644
--- a/win32/makefile.mk
+++ b/win32/makefile.mk
@@ -1703,7 +1703,7 @@ utils: $(HAVEMINIPERL) ..\utils\Makefile
 	copy ..\README.tw       ..\pod\perltw.pod
 	copy ..\README.vos      ..\pod\perlvos.pod
 	copy ..\README.win32    ..\pod\perlwin32.pod
-	copy ..\pod\perldelta.pod ..\pod\perl5336delta.pod
+	copy ..\pod\perldelta.pod ..\pod\perl5337delta.pod
 	$(MINIPERL) -I..\lib $(PL2BAT) $(UTILS)
 	$(MINIPERL) -I..\lib ..\autodoc.pl ..
 	$(MINIPERL) -I..\lib ..\pod\perlmodlib.PL -q ..
@@ -1801,7 +1801,7 @@ distclean: realclean
 	-if exist $(LIBDIR)\Win32API rmdir /s /q $(LIBDIR)\Win32API
 	-if exist $(LIBDIR)\XS rmdir /s /q $(LIBDIR)\XS
 	-cd $(PODDIR) && del /f *.html *.bat roffitall \
-	    perl5336delta.pod perlaix.pod perlamiga.pod perlandroid.pod \
+	    perl5337delta.pod perlaix.pod perlamiga.pod perlandroid.pod \
 	    perlapi.pod perlbs2000.pod perlcn.pod perlcygwin.pod \
 	    perldos.pod perlfreebsd.pod perlhaiku.pod perlhpux.pod \
 	    perlhurd.pod perlintern.pod perlirix.pod perljp.pod perlko.pod \
diff --git a/win32/pod.mak b/win32/pod.mak
index 1e7329566b..1d3cb5083b 100644
--- a/win32/pod.mak
+++ b/win32/pod.mak
@@ -70,6 +70,7 @@ POD = perl.pod	\
 	perl5334delta.pod	\
 	perl5335delta.pod	\
 	perl5336delta.pod	\
+	perl5337delta.pod	\
 	perl561delta.pod	\
 	perl56delta.pod	\
 	perl581delta.pod	\
@@ -238,6 +239,7 @@ MAN = perl.man	\
 	perl5334delta.man	\
 	perl5335delta.man	\
 	perl5336delta.man	\
+	perl5337delta.man	\
 	perl561delta.man	\
 	perl56delta.man	\
 	perl581delta.man	\
@@ -406,6 +408,7 @@ HTML = perl.html	\
 	perl5334delta.html	\
 	perl5335delta.html	\
 	perl5336delta.html	\
+	perl5337delta.html	\
 	perl561delta.html	\
 	perl56delta.html	\
 	perl581delta.html	\
@@ -574,6 +577,7 @@ TEX = perl.tex	\
 	perl5334delta.tex	\
 	perl5335delta.tex	\
 	perl5336delta.tex	\
+	perl5337delta.tex	\
 	perl561delta.tex	\
 	perl56delta.tex	\
 	perl581delta.tex	\