X-Git-Url: https://perl5.git.perl.org/perl5.git/blobdiff_plain/e61cab1ae55f80d9be2ae83f1a64a72c2b0e2f41..12cd6c6b7c1f412faa98318e7c8571489cc4e44b:/pod/perldelta.pod

diff --git a/pod/perldelta.pod b/pod/perldelta.pod
index af358ca..84a8382 100644
--- a/pod/perldelta.pod
+++ b/pod/perldelta.pod
@@ -1,3 +1,8 @@
+=for todo
+b47a847f62 win32/win32sck.c: dont close() a freed socket os handle
+35e037e846 Commit 1735f6f started to escape all...
+9b4bdfd44e fix chop formats with non PV vars
+
 =encoding utf8
 
 =head1 NAME
@@ -27,6 +32,13 @@ here, but most should go in the L</Performance Enhancements> section.
 
 [ List each enhancement as a =head2 entry ]
 
+=head2 $a and $b warnings exemption
+
+The special variables $a and $b, used in C<sort>, are now exempt from "used
+once" warnings, even where C<sort> is not used.  This makes it easier for
+CPAN modules to provide functions using $a and $b for similar purposes.
+[perl #120462]
+
 =head1 Security
 
 XXX Any security-related notices go here.  In particular, any security
@@ -86,7 +98,10 @@ There may well be none in a stable release.
 
 =item *
 
-XXX
+Constant hash key lookups (C<$hash{key}> as opposed to C<$hash{$key}>) have
+long had the internal hash value computed at compile time, to speed up
+lookup.  This optimisation has only now been applied to hash slices as
+well.
 
 =back
 
@@ -125,6 +140,35 @@ chr 256 remains chr 256, instead of turning into "\xc4\x80".  This allows
 L<B::Deparse> to deparse Unicode regular expression correctly.
 [perl #120182]
 
+C<< B::HV->ARRAY >> now preserves the UTF8 flag on returned hash keys.
+[perl #120535]
+
+=item *
+
+L<B::Concise> has been upgraded from version 0.99 to 0.991.
+
+B<-debug> output now includes C<op_other> pointers.
+
+=item *
+
+L<B::Deparse> has been upgraded from version 1.23 to 1.24.
+
+C<s//\(3)/e> is now deparsed in a way that does not issue warnings when
+parsed again.  [perl #119807]
+
+C<glob(my $x)> is now deparsed correctly, rather than as C<< <my $x> >> or
+similar.
+
+C<CORE::glob> is now deparsed correctly with the CORE:: prefix when there
+is a subroutine named "glob".
+
+=item *
+
+L<IO::Select> has been upgraded from version 1.21 to 1.22.
+
+Removing a closed file handle from an IO::Select object now correctly
+updates its internal state and returns the correct value.  [perl #75156]
+
 =item *
 
 L<Module::CoreList> has been upgraded from version 3.00 to 3.01.
@@ -133,6 +177,14 @@ The list of Perl versions covered has been updated.
 
 =item *
 
+L<PerlIO::scalar> has been upgraded from version 0.17 to 0.18.
+
+A bug fix in 0.17 caused references to be stringified as soon as a handle
+to it was opened, even if it was opened only for reading.  It also croaked
+on read-only references.  This has been fixed.  [perl #119529]
+
+=item *
+
 L<Tie::StdHandle> has been upgraded from version 4.3 to 4.4.
 
 It no longer prints C<$\> twice.  [perl #120202]
@@ -222,7 +274,11 @@ XXX Changes (i.e. rewording) of diagnostic messages go here
 
 =item *
 
-XXX Describe change here
+L<%%s[%s] in scalar context better written as $%s[%s]|perldiag/"%%s[%s] in scalar context better written as $%s[%s]">:
+
+This warning now occurs for any C<%array[$index]> or C<%hash{key}> known to
+be in scalar context at compile time.  Previously it was worded "Scalar
+value %%s[%s] better written as $%s[%s]".
 
 =back
 
@@ -276,7 +332,9 @@ that they represent may be covered elsewhere.
 
 =item *
 
-XXX
+F<ext/File-Find/t/find.t> has been converted from manual C<print>
+statements to Test::More functions.  Each test now has a description.
+[perl #120503]
 
 =back
 
@@ -344,7 +402,9 @@ well.
 
 =item *
 
-XXX
+Compiling with C<-Accflags=-PERL_BOOL_AS_CHAR> now allows C99 and C++
+compilers to emulate the aliasing of C<bool> to C<char> that perl does for
+C89 compilers.  [perl #120314]
 
 =back
 
@@ -359,7 +419,8 @@ files in F<ext/> and F<lib/> are best summarized in L</Modules and Pragmata>.
 
 =item *
 
-XXX
+Perl 5.18.0 accidentally disallowed C<-bareword> under C<use strict> and
+C<use integer>.  This has been fixed.  [perl #120288]
 
 =item *
 
@@ -367,6 +428,161 @@ C<-a> at the start of a line (or a hyphen with any single letter that is
 not a filetest operator) no longer produces an erroneous 'Use of "-a"
 without parentheses is ambiguous' warning.  [perl #120288]
 
+=item *
+
+Lvalue context is now properly propagated into bare blocks and C<if> and
+C<else> blocks in lvalue subroutines.  Previously, arrays and hashes would
+sometimes incorrectly be flattened when returned in lvalue list context, or
+"Bizarre copy" errors could occur.  [perl #119797]
+
+=item *
+
+Lvalue context is now propagated to the branches of C<||> and C<&&> (and
+their alphabetic equivalents, C<or> and C<and>).  This means
+C<foreach (pos $x || pos $y) {...}> now allows C<pos> to be modified
+through $_.
+
+=item *
+
+C<*DB::DB = sub {} if 0> no longer stops Perl's debugging mode from finding
+C<DB::DB> subs declared thereafter.
+
+=item *
+
+C<stat> and C<readline> remember the last handle used; the former
+for the special C<_> filehandle, the latter for C<${^LAST_FH}>.
+C<eval "*foo if 0"> where *foo was the last handle passed to C<stat>
+or C<readline> could cause that handle to be forgotten if the
+handle were not opened yet.  This has been fixed.
+
+=item *
+
+Various cases of C<delete $::{a}>, C<delete $::{ENV}> etc. causing a crash
+have been fixed.  [perl #54044]
+
+=item *
+
+Assigning another typeglob to C<*^R> no longer makes the regular expression
+engine crash.
+
+=item *
+
+C<%{'_<...'}> hashes now set breakpoints on the corresponding C<@{'_<...'}>
+rather than whichever array C<@DB::dbline> is aliased to.  [perl #119799]
+
+=item *
+
+Setting C<$!> to EACCESS before calling C<require> could affect
+C<require>'s behaviour.  This has been fixed.
+
+=item *
+
+The "Can't use \1 to mean $1 in expression" warning message now only occurs
+on the right-hand (replacement) part of a substitution.  Formerly it could
+happen in code embedded in the left-hand side, or in any other quote-like
+operator.
+
+=item *
+
+The C<\N> regular expression escape, when used without the curly braces (to
+mean C<[^\n]>), was ignoring a following C<*> if followed by whitespace
+under /x.  It had been this way since C<\N> to mean C<[^\n]> was introduced
+in 5.12.0.
+
+=item *
+
+Blessing into a reference (C<bless $thisref, $thatref>) has long been
+disallowed, but magical scalars for the second like C<$/> and those tied
+were exempt.  They no longer are.  [perl #119809]
+
+=item *
+
+Blessing into a reference was accidentally allowed in 5.18 if the class
+argument were a blessed reference with stale method caches (i.e., whose
+class had had subs defined since the last method call).  They are
+disallowed once more, as in 5.16.
+
+=item *
+
+An undefined lexical sub used as an inherited method no longer crashes.
+
+=item *
+
+C<< $x->{key} >> where $x was declared as C<my Class $x> no longer crashes
+if a Class::FIELDS subroutine stub has been declared.
+
+=item *
+
+C<@$obj{'key'}> and C<${$obj}{key}> used to be exempt from compile-time
+field checking ("No such class field"; see L<fields>) but no longer are.
+
+=item *
+
+That compile-time field checking also applies now to the C<%$obj{'key'}>
+syntax, added recently in Perl 5.19.4.
+
+=item *
+
+A nonexistent array element with a large index passed to a subroutine that
+ties the array and then tries to access the element no longer results in a
+crash.
+
+=item *
+
+Declaring a subroutine stub named NEGATIVE_INDICES no longer makes negative
+array indices crash when the current package is a tied array class.
+
+=item *
+
+Declaring a C<require>, C<glob>, or C<do> subroutine stub in the
+CORE::GLOBAL:: package no longer makes compilation of calls to the
+corresponding functions crash.
+
+=item *
+
+Aliasing CORE::GLOBAL:: functions to constants stopped working in Perl 5.10
+but has now been fixed.
+
+=item *
+
+When C<`...`> or C<qx/.../> calls a C<readpipe> override, double-quotish
+interpolation now happens, as is the case when there is no override.
+Previously, the presence of an override would make these quote-like
+operators act like C<q{}>, suppressing interpolation.  [perl #115330]
+
+=item *
+
+C<<<`...`> here-docs (with backticks as the delimiters) now call
+C<readpipe> overrides.  [perl #119827]
+
+=item *
+
+The presence of a lexical sub named "CORE" no longer stops the CORE::
+prefix from working.
+
+=item *
+
+C<&CORE::exit()> and C<&CORE::die()> now respect L<vmsish> hints.
+
+=item *
+
+Undefining a glob that triggers a DESTROY method that undefines the same
+glob is now safe.  It used to produce "Attempt to free unreferenced glob
+pointer" warnings and leak memory.
+
+=item *
+
+If subroutine redefinition (C<eval 'sub foo{}'> or C<newXS> for XS code)
+triggers a DESTROY method on the sub that is being redefined, and that
+method assigns a subroutine to the same slot (C<*foo = sub {}>), C<$_[0]>
+is no longer left pointing to a freed scalar.  Now DESTROY is delayed until
+the new subroutine has been installed.
+
+=item *
+
+C<s///>, C<tr///> and C<y///> now work when a wide character is used as the
+delimiter.  [perl #120463]
+
 =back
 
 =head1 Known Problems
@@ -381,8 +597,10 @@ platform specific bugs also go here.
 
 =item *
 
-Perl 5.18.0 accidentally disallowed C<-bareword> under C<use strict> and
-C<use integer>.  This has been fixed.  [perl #120288]
+C<do CORE()> used to call a sub named "CORE" and treat its return value as
+a file name to execute.  A bug fix inadvertently caused it to be
+interpreted as the deprecated "do-SUB" construct.  (Yes, C<do
+I<bareword>()> is inconsistent.)  This will likely be changed back.
 
 =back