[ 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 v5.17.7
+perldelta - what is new for perl v5.17.11
=head1 DESCRIPTION
-This document describes differences between the 5.17.6 release and the 5.17.7
+This document describes differences between the 5.17.10 release and the 5.17.11
release.
-If you are upgrading from an earlier release such as 5.17.5, first read
-L<perl5176delta>, which describes differences between 5.17.5 and 5.17.6.
+If you are upgrading from an earlier release such as 5.17.9, first read
+L<perl51710delta>, which describes differences between 5.17.9 and 5.17.10.
=head1 Notice
=head1 Core Enhancements
-=head2 $&, $` and $' are no longer slow
+XXX New core language features go here. Summarize user-visible core language
+enhancements. Particularly prominent performance optimisations could go
+here, but most should go in the L</Performance Enhancements> section.
-These three infamous variables have been redeemed and no longer slow down
-your program when used. Hence, the /p regular expression flag now does
-nothing.
+[ List each enhancement as a =head2 entry ]
=head1 Security
=head1 Incompatible Changes
-=head2 readline() with C<$/ = \N> now reads N characters, not N bytes
+XXX For a release on a stable branch, this section aspires to be:
-Previously, when reading from a stream with I/O layers such as
-C<encoding>, the readline() function, otherwise known as the C<< <> >>
-operator, would read I<N> bytes from the top-most layer. [perl #79960]
+ 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.
-Now, I<N> characters are read instead.
-
-There is no change in behaviour when reading from streams with no
-extra layers, since bytes map exactly to characters.
-
-=head2 Lexical subroutine warnings have moved
-
-The warning about the use of an experimental feature emitted when lexical
-subroutines (added in 5.17.4) are used now happens when the subroutine
-itself is declared, not when the "lexical_subs" feature is activated via
-C<use feature>.
-
-This stops C<use feature ':all'> from warning, but causes
-C<my sub foo; my sub bar> to warn twice.
+[ List each incompatible change as a =head2 entry ]
=head1 Deprecations
[ List each deprecation as a =head2 entry ]
-=head2 Various XS-callable functions are now deprecated
-
-The following functions will be removed from a future version of Perl,
-and should not be used. With participating C compilers (e.g., gcc),
-compiling any file that uses any of these will generate a warning.
-These were not intended for public use; there are equivalent, faster,
-macros for most of them. See L<perlapi/Character classes>:
-C<is_uni_ascii>,
-C<is_uni_ascii_lc>,
-C<is_uni_blank>,
-C<is_uni_blank_lc>,
-C<is_uni_cntrl>,
-C<is_uni_cntrl_lc>,
-C<is_uni_idfirst_lc>,
-C<is_uni_space>,
-C<is_uni_space_lc>,
-C<is_uni_xdigit>,
-C<is_uni_xdigit_lc>,
-C<is_utf8_ascii>,
-C<is_utf8_blank>,
-C<is_utf8_cntrl>,
-C<is_utf8_idcont>,
-C<is_utf8_idfirst>,
-C<is_utf8_perl_space>,
-C<is_utf8_perl_word>,
-C<is_utf8_posix_digit>,
-C<is_utf8_space>,
-C<is_utf8_xdigit>.
-C<is_utf8_xidcont>,
-C<is_utf8_xidfirst>,
-C<to_uni_lower_lc>,
-C<to_uni_title_lc>,
-and
-C<to_uni_upper_lc>.
-
=head1 Performance Enhancements
XXX Changes which enhance performance without changing behaviour go here.
=item *
-Perl has a new copy-on-write mechanism that avoids the need to copy the
-internal string buffer when assigning from one scalar to another. This
-makes copying large strings appear much faster. Modifying one of the two
-(or more) strings after an assignment will force a copy internally. This
-makes it unnecessary to pass strings by reference for efficiency.
+XXX
=back
=item *
-L<GDBM_File> has been upgraded from version 1.14 to 1.15. The undocumented
-optional fifth parameter to C<TIEHASH> has been removed. This was intended
-to provide control of the callback used by C<gdbm*> functions in case of
-fatal errors (such as filesystem problems), but did not work (and could
-never have worked). No code on CPAN even attempted to use it. The callback
-is now always the previous default, C<croak>. Problems on some platforms with
-how the C<C> C<croak> function is called have also been resolved.
+Fixed the merge of ExtUtils-MakeMaker 6.65_01 to remove an excluded
+file. This was causing a test failure on Win32 [perl #117477]
+
+=item *
+
+L<XXX> has been upgraded from version A.xx to B.yy.
=back
However, any changes to F<pod/perldiag.pod> should go in the L</Diagnostics>
section.
-=head3 L<perlapi/Character classes>
+=head3 L<XXX>
=over 4
=item *
-There are quite a few macros callable from XS modules that classify
-characters into things like alphabetic, punctuation, etc. More of these
-are now documented, including ones which work on characters whose code
-points are outside the Latin-1 range.
+XXX Description of the change here
=back
=item *
-XXX L<message|perldiag/"message">
+L<Smartmatch is experimental|perldiag/"Smartmatch is experimental">
+
+=item *
+
+L<given is experimental|perldiag/"given is experimental">
+
+=item *
+
+L<when is experimental|perldiag/"when is experimental">
=back
=head2 Discontinued Platforms
+XXX List any platforms that this version of perl no longer compiles on.
+
=over 4
-=item BeOS
+=item XXX-some-platform
-Support for BeOS has been removed.
+XXX
=back
=item *
-SvUPGRADE() is no longer an expression. Originally this macro (and its
-underlying function, sv_upgrade()) were documented as boolean, although
-in reality they always croaked on error and never returned false. In 2005
-the documentation was updated to specify a void return value, but
-SvUPGRADE() was left always returning 1 for backwards compatibility. This
-has now been removed, and SvUPGRADE() is now a statement with no return
-value.
-
-So this is now a syntax error:
-
- if (!SvUPGRADE(sv)) { croak(...); }
-
-If you have code like that, simply replace it with
-
- SvUPGRADE(sv);
-
-or to to avoid compiler warnings with older perls, possibly
-
- (void)SvUPGRADE(sv);
-
-=item *
-
-Perl has a new copy-on-write mechanism that allows any SvPOK scalar to be
-upgraded to a copy-on-write scalar. A reference count on the string buffer
-is stored in the string buffer itself.
-
-This breaks a few XS modules by allowing copy-on-write scalars to go
-through code paths that never encountered them before.
-
-This behaviour can still be disabled by running F<Configure> with
-B<-Accflags=-DPERL_NO_COW>. This option will probably be removed in Perl
-5.20.
-
-=item *
-
-Copy-on-write no longer uses the SvFAKE and SvREADONLY flags. Hence,
-SvREADONLY indicates a true read-only SV.
-
-Use the SvIsCOW macro (as before) to identify a copy-on-write scalar.
-
-=item *
-
-C<PL_sawampersand> is now a constant. The switch this variable provided
-(to enable/disable the pre-match copy depending on whether C<$&> had been
-seen) has been removed and replaced with copy-on-write, eliminating a few
-bugs.
-
-The previous behaviour can still be enabled by running F<Configure> with
-B<-Accflags=-DPERL_SAWAMPERSAND>.
+XXX
=back
=item *
-C<sort {undef} ...> under fatal warnings no longer crashes. It started
-crashing in Perl 5.16.
-
-=item *
-
-Stashes blessed into each other
-(C<bless \%Foo::, 'Bar'; bless \%Bar::, 'Foo'>) no longer result in double
-frees. This bug started happening in Perl 5.16.
-
-=item *
-
-Numerous memory leaks have been fixed, mostly involving fatal warnings and
-syntax errors.
-
-=item *
-
-Lexical constants (C<my sub answer () { 42 }>) no longer cause double
-frees.
-
-=item *
-
-Constant subroutine redefinition warns by default, but lexical constants
-were accidentally exempt from default warnings. This has been corrected.
-
-=item *
-
-Some failed regular expression matches such as C<'f' =~ /../g> were not
-resetting C<pos>. Also, "match-once" patterns (C<m?...?g>) failed to reset
-it, too, when invoked a second time [perl #23180].
-
-=item *
-
-Accessing C<$&> after a pattern match now works if it had not been seen
-before the match. I.e., this applies to C<${'&'}> (under C<no strict>) and
-C<eval '$&'>. The same applies to C<$'> and C<$`> [perl #4289].
+XXX
=back
XXX Generate this with:
- perl Porting/acknowledgements.pl v5.17.6..HEAD
+ perl Porting/acknowledgements.pl v5.17.10..HEAD
=head1 Reporting Bugs