X-Git-Url: https://perl5.git.perl.org/perl5.git/blobdiff_plain/a19564f7dac42c5dc47e1e3e792d670223548c44..4ee2b8db537d28b77d127a86307e426289e5c8b5:/pod/perldelta.pod

diff --git a/pod/perldelta.pod b/pod/perldelta.pod
index c218051..467f17f 100644
--- a/pod/perldelta.pod
+++ b/pod/perldelta.pod
@@ -5,15 +5,15 @@
 [ 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 v5.25.6
+perldelta - what is new for perl v5.25.9
 
 =head1 DESCRIPTION
 
-This document describes differences between the 5.25.5 release and the 5.25.6
+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 5.25.4, first read
-L<perl5255delta>, which describes differences between 5.25.4 and 5.25.5.
+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
 
@@ -47,7 +47,15 @@ XXX For a release on a stable branch, this section aspires to be:
 
 =head1 Deprecations
 
-XXX Any deprecated features, syntax, modules etc. should be listed here.
+=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
 
@@ -80,19 +88,16 @@ as an updated module in the L</Modules and Pragmata> section.
 
 =head1 Performance Enhancements
 
-=over 4
+XXX Changes which enhance performance without changing behaviour go here.
+There may well be none in a stable release.
 
-=item *
+[ List each enhancement as a =item entry ]
 
-Converting a single-digit string to a number is now substantially faster.
+=over 4
 
 =item *
 
-The internal op implementing the C<split> builtin has been simplified and
-sped up. Firstly, it no longer requires a subsidiary internal C<pushre> op
-to do its work. Secondly, code of the form C<my @x = split(...)> is now
-optimised in the same way as C<@x = split(...)>, and is therefore a few
-percent faster.
+XXX
 
 =back
 
@@ -122,12 +127,79 @@ XXX
 
 =item *
 
-L<B::Concise> now produces output that is more descriptive for C<op_private>
-flags.
+L<XXX> has been upgraded from version A.xx to B.yy.
 
 =item *
 
-L<XXX> has been upgraded from version A.xx to B.yy.
+L<B::Xref> has been upgraded from version 1.05 to 1.06.
+
+=item *
+
+L<VMS::DCLsym> has been upgraded from version 1.07 to 1.08.
+
+=item *
+
+L<diagnostics> has been upgraded from version 1.35 to 1.36.
+
+=item *
+
+L<Devel::SelfStubber> has been upgraded from version 1.05 to 1.06.
+
+=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<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 2.60.
+
+=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<Unicode::UCD> has been upgraded from version 0.67 to 0.68.
+
+=item *
+
+L<XSLoader> has been upgraded from version 0.24 to 0.26.
 
 =back
 
@@ -212,15 +284,7 @@ XXX Changes (i.e. rewording) of diagnostic messages go here
 
 =item *
 
-Details as to the exact problem have been added to the diagnostics that
-occur when malformed UTF-8 is encountered when trying to convert to a
-code point.
-
-=item *
-
-Executing C<undef $x> where C<$x> is tied or magical no longer incorrectly
-blames the variable for an uninitialized-value warning encountered by the
-tied/magical code.
+XXX Describe change here
 
 =back
 
@@ -256,8 +320,7 @@ L</Platform Support> section, instead.
 
 =item *
 
-Builds using C<USE_PAD_RESET> now work again; this configuration had
-bit-rotted.
+XXX
 
 =back
 
@@ -275,11 +338,7 @@ that they represent may be covered elsewhere.
 
 =item *
 
-Some parts of the test suite that try to exhaustively test edge cases in the
-regex implementation have been restricted to running for a maximum of five
-minutes. On slow systems they could otherwise take several hours, without
-significantly improving our understanding of the correctness of the code
-under test.
+XXX
 
 =back
 
@@ -292,16 +351,16 @@ 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 NetBSD/VAX
+=item XXX-some-platform
 
-Perl now compiles under NetBSD on VAX machines.  However, it's not
-possible for that platform to implement floating-point infinities and
-NaNs compatibly with most modern systems, which implement the IEEE-754
-floating point standard.  The hexadecimal floating point (C<0x...p[+-]n>
-literals, C<printf %a>) is not implemented, either.
-The C<make test> passes 98% of tests.
+XXX
 
 =back
 
@@ -344,51 +403,47 @@ well.
 
 =item *
 
-The C<PADOFFSET> type has changed from being unsigned to signed, and
-several pad-related variables such as C<PL_padix> have changed from being
-of type C<I32> to type C<PADOFFSET>.
+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 function C<L<perlapi/utf8n_to_uvchr>> has been changed to not
-abandon searching for other malformations when the first one is
-encountered.  A call to it thus can generate multiple diagnostics,
-instead of just one.
+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 *
 
-A new function, C<L<perlapi/utf8n_to_uvchr_error>>, has been added for
-use by modules that need to know the details of UTF-8 malformations
-beyond pass/fail.  Previously, the only ways to know why a sequence was
-ill-formed was to capture and parse the generated diagnostics, or to do
-your own analysis.
+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 *
 
-Several new functions for handling Unicode have been added to the API:
-C<L<perlapi/is_strict_utf8_string>>,
-C<L<perlapi/is_c9strict_utf8_string>>,
-C<L<perlapi/is_utf8_string_flags>>,
-C<L<perlapi/is_strict_utf8_string_loc>>,
-C<L<perlapi/is_strict_utf8_string_loclen>>,
-C<L<perlapi/is_c9strict_utf8_string_loc>>,
-C<L<perlapi/is_c9strict_utf8_string_loclen>>,
-C<L<perlapi/is_utf8_string_loc_flags>>,
-C<L<perlapi/is_utf8_string_loclen_flags>>,
-C<L<perlapi/is_utf8_fixed_width_buf_flags>>,
-C<L<perlapi/is_utf8_fixed_width_buf_loc_flags>>,
-C<L<perlapi/is_utf8_fixed_width_buf_loclen_flags>>.
-
-These functions are all extensions of the C<is_utf8_string_*()> functions,
-that apply various restrictions to the UTF-8 recognized as valid.
+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 *
 
-All parts of the internals now agree that the C<sassign> op is a C<BINOP>;
-previously it was listed as a C<BASEOP> in F<regen/opcodes>, which meant
-that several parts of the internals had to be special-cased to accommodate
-it. This oddity's original motivation was to handle code like C<$x ||= 1>;
-that is now handled in a simpler way.
+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
 
@@ -403,20 +458,8 @@ files in F<ext/> and F<lib/> are best summarized in L</Modules and Pragmata>.
 
 =item *
 
-A sub containing a "forward" declaration with the same name (e.g.,
-C<sub c { sub c; }>) could sometimes crash or loop infinitely.  [perl
-#129090]
-
-=item *
-
-A crash in executing a regex with a floating UTF-8 substring against a
-target string that also used UTF-8 has been fixed. [perl #129350]
-
-=item *
-
-Previously, a shebang line like C<#!perl -i u> could be erroneously
-interpreted as requesting the C<-u> option. This has been fixed. [perl
-#129336]
+Under C<use utf8>, the entire Perl program is now checked that the UTF-8
+is wellformed.  This resolves [perl #126310].
 
 =back