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+=encoding utf8
+
+=head1 NAME
+
+perl5140delta - what is new for perl v5.14.0
+
+=head1 DESCRIPTION
+
+This document describes differences between the 5.12.0 release and
+the 5.14.0 release.
+
+If you are upgrading from an earlier release such as 5.10.0, first read
+L<perl5120delta>, which describes differences between 5.10.0 and
+5.12.0.
+
+Some of the bug fixes in this release have been backported to subsequent
+releases of 5.12.x. Those are indicated with the 5.12.x version in
+parentheses.
+
+=head1 Notice
+
+As described in L<perlpolicy>, the release of Perl 5.14.0 marks the
+official end of support for Perl 5.10. Users of Perl 5.10 or earlier
+should consider upgrading to a more recent release of Perl.
+
+=head1 Core Enhancements
+
+=head2 Unicode
+
+=head3 Unicode Version 6.0 is now supported (mostly)
+
+Perl comes with the Unicode 6.0 data base updated with
+L<Corrigendum #8|http://www.unicode.org/versions/corrigendum8.html>,
+with one exception noted below.
+See L<http://unicode.org/versions/Unicode6.0.0/> for details on the new
+release. Perl does not support any Unicode provisional properties,
+including the new ones for this release.
+
+Unicode 6.0 has chosen to use the name C<BELL> for the character at U+1F514,
+which is a symbol that looks like a bell, and is used in Japanese cell
+phones. This conflicts with the long-standing Perl usage of having
+C<BELL> mean the ASCII C<BEL> character, U+0007. In Perl 5.14,
+C<\N{BELL}> continues to mean U+0007, but its use generates a
+deprecation warning message unless such warnings are turned off. The
+new name for U+0007 in Perl is C<ALERT>, which corresponds nicely
+with the existing shorthand sequence for it, C<"\a">. C<\N{BEL}>
+means U+0007, with no warning given. The character at U+1F514 has no
+name in 5.14, but can be referred to by C<\N{U+1F514}>.
+In Perl 5.16, C<\N{BELL}> will refer to U+1F514; all code
+that uses C<\N{BELL}> should be converted to use C<\N{ALERT}>,
+C<\N{BEL}>, or C<"\a"> before upgrading.
+
+=head3 Full functionality for C<use feature 'unicode_strings'>
+
+This release provides full functionality for C<use feature
+'unicode_strings'>. Under its scope, all string operations executed and
+regular expressions compiled (even if executed outside its scope) have
+Unicode semantics. See L<feature/"the 'unicode_strings' feature">.
+However, see L</Inverted bracketed character classes and multi-character folds>,
+below.
+
+This feature avoids most forms of the "Unicode Bug" (see
+L<perlunicode/The "Unicode Bug"> for details). If there is any
+possibility that your code will process Unicode strings, you are
+I<strongly> encouraged to use this subpragma to avoid nasty surprises.
+
+=head3 C<\N{I<NAME>}> and C<charnames> enhancements
+
+=over
+
+=item *
+
+C<\N{I<NAME>}> and C<charnames::vianame> now know about the abbreviated
+character names listed by Unicode, such as NBSP, SHY, LRO, ZWJ, etc.; all
+customary abbreviations for the C0 and C1 control characters (such as
+ACK, BEL, CAN, etc.); and a few new variants of some C1 full names that
+are in common usage.
+
+=item *
+
+Unicode has several I<named character sequences>, in which particular sequences
+of code points are given names. C<\N{I<NAME>}> now recognizes these.
+
+=item *
+
+C<\N{I<NAME>}>, C<charnames::vianame>, and C<charnames::viacode>
+now know about every character in Unicode. In earlier releases of
+Perl, they didn't know about the Hangul syllables nor several
+CJK (Chinese/Japanese/Korean) characters.
+
+=item *
+
+It is now possible to override Perl's abbreviations with your own custom aliases.
+
+=item *
+
+You can now create a custom alias of the ordinal of a
+character, known by C<\N{I<NAME>}>, C<charnames::vianame()>, and
+C<charnames::viacode()>. Previously, aliases had to be to official
+Unicode character names. This made it impossible to create an alias for
+unnamed code points, such as those reserved for private
+use.
+
+=item *
+
+The new function charnames::string_vianame() is a run-time version
+of C<\N{I<NAME>}}>, returning the string of characters whose Unicode
+name is its parameter. It can handle Unicode named character
+sequences, whereas the pre-existing charnames::vianame() cannot,
+as the latter returns a single code point.
+
+=back
+
+See L<charnames> for details on all these changes.
+
+=head3 New warnings categories for problematic (non-)Unicode code points.
+
+Three new warnings subcategories of "utf8" have been added. These
+allow you to turn off some "utf8" warnings, while allowing
+other warnings to remain on. The three categories are:
+C<surrogate> when UTF-16 surrogates are encountered;
+C<nonchar> when Unicode non-character code points are encountered;
+and C<non_unicode> when code points above the legal Unicode
+maximum of 0x10FFFF are encountered.
+
+=head3 Any unsigned value can be encoded as a character
+
+With this release, Perl is adopting a model that any unsigned value
+can be treated as a code point and encoded internally (as utf8)
+without warnings, not just the code points that are legal in Unicode.
+However, unless utf8 or the corresponding sub-category (see previous
+item) of lexical warnings have been explicitly turned off, outputting
+or executing a Unicode-defined operation such as upper-casing
+on such a code point generates a warning. Attempting to input these
+using strict rules (such as with the C<:encoding(UTF-8)> layer)
+will continue to fail. Prior to this release, handling was
+inconsistent and in places, incorrect.
+
+Unicode non-characters, some of which previously were erroneously
+considered illegal in places by Perl, contrary to the Unicode Standard,
+are now always legal internally. Inputting or outputting them
+works the same as with the non-legal Unicode code points, because the Unicode
+Standard says they are (only) illegal for "open interchange".
+
+=head3 Unicode database files not installed
+
+The Unicode database files are no longer installed with Perl. This
+doesn't affect any functionality in Perl and saves significant disk
+space. If you need these files, you can download them from
+L<http://www.unicode.org/Public/zipped/6.0.0/>.
+
+=head2 Regular Expressions
+
+=head3 C<(?^...)> construct signifies default modifiers
+
+An ASCII caret C<"^"> immediately following a C<"(?"> in a regular
+expression now means that the subexpression does not inherit surrounding
+modifiers such as C</i>, but reverts to the Perl defaults. Any modifiers
+following the caret override the defaults.
+
+Stringification of regular expressions now uses this notation.
+For example, C<qr/hlagh/i> would previously be stringified as
+C<(?i-xsm:hlagh)>, but now it's stringified as C<(?^i:hlagh)>.
+
+The main purpose of this change is to allow tests that rely on the
+stringification I<not> to have to change whenever new modifiers are added.
+See L<perlre/Extended Patterns>.
+
+This change is likely to break code that compares stringified regular
+expressions with fixed strings containing C<?-xism>.
+
+=head3 C</d>, C</l>, C</u>, and C</a> modifiers
+
+Four new regular expression modifiers have been added. These are mutually
+exclusive: one only can be turned on at a time.
+
+=over
+
+=item *
+
+The C</l> modifier says to compile the regular expression as if it were
+in the scope of C<use locale>, even if it is not.
+
+=item *
+
+The C</u> modifier says to compile the regular expression as if it were
+in the scope of a C<use feature 'unicode_strings'> pragma.
+
+=item *
+
+The C</d> (default) modifier is used to override any C<use locale> and
+C<use feature 'unicode_strings'> pragmas in effect at the time
+of compiling the regular expression.
+
+=item *
+
+The C</a> regular expression modifier restricts C<\s>, C<\d> and C<\w> and
+the POSIX (C<[[:posix:]]>) character classes to the ASCII range. Their
+complements and C<\b> and C<\B> are correspondingly
+affected. Otherwise, C</a> behaves like the C</u> modifier, in that
+case-insensitive matching uses Unicode semantics.
+
+If the C</a> modifier is repeated, then additionally in case-insensitive
+matching, no ASCII character can match a non-ASCII character.
+For example,
+
+ "k" =~ /\N{KELVIN SIGN}/ai
+ "\xDF" =~ /ss/ai
+
+match but
+
+ "k" =~ /\N{KELVIN SIGN}/aai
+ "\xDF" =~ /ss/aai
+
+do not match.
+
+=back
+
+See L<perlre/Modifiers> for more detail.
+
+=head3 Non-destructive substitution
+
+The substitution (C<s///>) and transliteration
+(C<y///>) operators now support an C</r> option that
+copies the input variable, carries out the substitution on
+the copy, and returns the result. The original remains unmodified.
+
+ my $old = "cat";
+ my $new = $old =~ s/cat/dog/r;
+ # $old is "cat" and $new is "dog"
+
+This is particularly useful with C<map>. See L<perlop> for more examples.
+
+=head3 Re-entrant regular expression engine
+
+It is now safe to use regular expressions within C<(?{...})> and
+C<(??{...})> code blocks inside regular expressions.
+
+These blocks are still experimental, however, and still have problems with
+lexical (C<my>) variables and abnormal exiting.
+
+=head3 C<use re '/flags'>
+
+The C<re> pragma now has the ability to turn on regular expression flags
+till the end of the lexical scope:
+
+ use re "/x";
+ "foo" =~ / (.+) /; # /x implied
+
+See L<re/"'/flags' mode"> for details.
+
+=head3 \o{...} for octals
+
+There is a new octal escape sequence, C<"\o">, in doublequote-like
+contexts. This construct allows large octal ordinals beyond the
+current max of 0777 to be represented. It also allows you to specify a
+character in octal which can safely be concatenated with other regex
+snippets and which won't be confused with being a backreference to
+a regex capture group. See L<perlre/Capture groups>.
+
+=head3 Add C<\p{Titlecase}> as a synonym for C<\p{Title}>
+
+This synonym is added for symmetry with the Unicode property names
+C<\p{Uppercase}> and C<\p{Lowercase}>.
+
+=head3 Regular expression debugging output improvement
+
+Regular expression debugging output (turned on by C<use re 'debug'>) now
+uses hexadecimal when escaping non-ASCII characters, instead of octal.
+
+=head3 Return value of C<delete $+{...}>
+
+Custom regular expression engines can now determine the return value of
+C<delete> on an entry of C<%+> or C<%->.
+
+=head2 Syntactical Enhancements
+
+=head3 Array and hash container functions accept references
+
+B<Warning:> This feature is considered experimental, as the exact behaviour
+may change in a future version of Perl.
+
+All builtin functions that operate directly on array or hash
+containers now also accept unblessed hard references to arrays
+or hashes:
+
+ |----------------------------+---------------------------|
+ | Traditional syntax | Terse syntax |
+ |----------------------------+---------------------------|
+ | push @$arrayref, @stuff | push $arrayref, @stuff |
+ | unshift @$arrayref, @stuff | unshift $arrayref, @stuff |
+ | pop @$arrayref | pop $arrayref |
+ | shift @$arrayref | shift $arrayref |
+ | splice @$arrayref, 0, 2 | splice $arrayref, 0, 2 |
+ | keys %$hashref | keys $hashref |
+ | keys @$arrayref | keys $arrayref |
+ | values %$hashref | values $hashref |
+ | values @$arrayref | values $arrayref |
+ | ($k,$v) = each %$hashref | ($k,$v) = each $hashref |
+ | ($k,$v) = each @$arrayref | ($k,$v) = each $arrayref |
+ |----------------------------+---------------------------|
+
+This allows these builtin functions to act on long dereferencing chains
+or on the return value of subroutines without needing to wrap them in
+C<@{}> or C<%{}>:
+
+ push @{$obj->tags}, $new_tag; # old way
+ push $obj->tags, $new_tag; # new way
+
+ for ( keys %{$hoh->{genres}{artists}} ) {...} # old way
+ for ( keys $hoh->{genres}{artists} ) {...} # new way
+
+=head3 Single term prototype
+
+The C<+> prototype is a special alternative to C<$> that acts like
+C<\[@%]> when given a literal array or hash variable, but will otherwise
+force scalar context on the argument. See L<perlsub/Prototypes>.
+
+=head3 C<package> block syntax
+
+A package declaration can now contain a code block, in which case the
+declaration is in scope inside that block only. So C<package Foo { ... }>
+is precisely equivalent to C<{ package Foo; ... }>. It also works with
+a version number in the declaration, as in C<package Foo 1.2 { ... }>,
+which is its most attractive feature. See L<perlfunc>.
+
+=head3 Statement labels can appear in more places
+
+Statement labels can now occur before any type of statement or declaration,
+such as C<package>.
+
+=head3 Stacked labels
+
+Multiple statement labels can now appear before a single statement.
+
+=head3 Uppercase X/B allowed in hexadecimal/binary literals
+
+Literals may now use either upper case C<0X...> or C<0B...> prefixes,
+in addition to the already supported C<0x...> and C<0b...>
+syntax [perl #76296].
+
+C, Ruby, Python, and PHP already support this syntax, and it makes
+Perl more internally consistent: a round-trip with C<eval sprintf
+"%#X", 0x10> now returns C<16>, just like C<eval sprintf "%#x", 0x10>.
+
+=head3 Overridable tie functions
+
+C<tie>, C<tied> and C<untie> can now be overridden [perl #75902].
+
+=head2 Exception Handling
+
+To make them more reliable and consistent, several changes have been made
+to how C<die>, C<warn>, and C<$@> behave.
+
+=over
+
+=item *
+
+When an exception is thrown inside an C<eval>, the exception is no
+longer at risk of being clobbered by destructor code running during unwinding.
+Previously, the exception was written into C<$@>
+early in the throwing process, and would be overwritten if C<eval> was
+used internally in the destructor for an object that had to be freed
+while exiting from the outer C<eval>. Now the exception is written
+into C<$@> last thing before exiting the outer C<eval>, so the code
+running immediately thereafter can rely on the value in C<$@> correctly
+corresponding to that C<eval>. (C<$@> is still also set before exiting the
+C<eval>, for the sake of destructors that rely on this.)
+
+Likewise, a C<local $@> inside an C<eval> no longer clobbers any
+exception thrown in its scope. Previously, the restoration of C<$@> upon
+unwinding would overwrite any exception being thrown. Now the exception
+gets to the C<eval> anyway. So C<local $@> is safe before a C<die>.
+
+Exceptions thrown from object destructors no longer modify the C<$@>
+of the surrounding context. (If the surrounding context was exception
+unwinding, this used to be another way to clobber the exception being
+thrown.) Previously such an exception was
+sometimes emitted as a warning, and then either was
+string-appended to the surrounding C<$@> or completely replaced the
+surrounding C<$@>, depending on whether that exception and the surrounding
+C<$@> were strings or objects. Now, an exception in this situation is
+always emitted as a warning, leaving the surrounding C<$@> untouched.
+In addition to object destructors, this also affects any function call
+run by XS code using the C<G_KEEPERR> flag.
+
+=item *
+
+Warnings for C<warn> can now be objects in the same way as exceptions
+for C<die>. If an object-based warning gets the default handling
+of writing to standard error, it is stringified as before with the
+filename and line number appended. But a C<$SIG{__WARN__}> handler now
+receives an object-based warning as an object, where previously it
+was passed the result of stringifying the object.
+
+=back
+
+=head2 Other Enhancements
+
+=head3 Assignment to C<$0> sets the legacy process name with prctl() on Linux
+
+On Linux the legacy process name is now set with L<prctl(2)>, in
+addition to altering the POSIX name via C<argv[0]>, as Perl has done
+since version 4.000. Now system utilities that read the legacy process
+name such as I<ps>, I<top>, and I<killall> recognize the name you set when
+assigning to C<$0>. The string you supply is truncated at 16 bytes;
+this limitation is imposed by Linux.
+
+=head3 srand() now returns the seed
+
+This allows programs that need to have repeatable results not to have to come
+up with their own seed-generating mechanism. Instead, they can use srand()
+and stash the return value for future use. One example is a test program with
+too many combinations to test comprehensively in the time available for
+each run. It can test a random subset each time and, should there be a failure,
+log the seed used for that run so this can later be used to produce the same results.
+
+=head3 printf-like functions understand post-1980 size modifiers
+
+Perl's printf and sprintf operators, and Perl's internal printf replacement
+function, now understand the C90 size modifiers "hh" (C<char>), "z"
+(C<size_t>), and "t" (C<ptrdiff_t>). Also, when compiled with a C99
+compiler, Perl now understands the size modifier "j" (C<intmax_t>)
+(but this is not portable).
+
+So, for example, on any modern machine, C<sprintf("%hhd", 257)> returns "1".
+
+=head3 New global variable C<${^GLOBAL_PHASE}>
+
+A new global variable, C<${^GLOBAL_PHASE}>, has been added to allow
+introspection of the current phase of the Perl interpreter. It's explained in
+detail in L<perlvar/"${^GLOBAL_PHASE}"> and in
+L<perlmod/"BEGIN, UNITCHECK, CHECK, INIT and END">.
+
+=head3 C<-d:-foo> calls C<Devel::foo::unimport>
+
+The syntax B<-d:foo> was extended in 5.6.1 to make B<-d:foo=bar>
+equivalent to B<-MDevel::foo=bar>, which expands
+internally to C<use Devel::foo 'bar'>.
+Perl now allows prefixing the module name with B<->, with the same
+semantics as B<-M>; that is:
+
+=over 4
+
+=item C<-d:-foo>
+
+Equivalent to B<-M-Devel::foo>: expands to
+C<no Devel::foo> and calls C<< Devel::foo->unimport() >>
+if that method exists.
+
+=item C<-d:-foo=bar>
+
+Equivalent to B<-M-Devel::foo=bar>: expands to C<no Devel::foo 'bar'>,
+and calls C<< Devel::foo->unimport("bar") >> if that method exists.
+
+=back
+
+This is particularly useful for suppressing the default actions of a
+C<Devel::*> module's C<import> method whilst still loading it for debugging.
+
+=head3 Filehandle method calls load L<IO::File> on demand
+
+When a method call on a filehandle would die because the method cannot
+be resolved and L<IO::File> has not been loaded, Perl now loads L<IO::File>
+via C<require> and attempts method resolution again:
+
+ open my $fh, ">", $file;
+ $fh->binmode(":raw"); # loads IO::File and succeeds
+
+This also works for globs like C<STDOUT>, C<STDERR>, and C<STDIN>:
+
+ STDOUT->autoflush(1);
+
+Because this on-demand load happens only if method resolution fails, the
+legacy approach of manually loading an L<IO::File> parent class for partial
+method support still works as expected:
+
+ use IO::Handle;
+ open my $fh, ">", $file;
+ $fh->autoflush(1); # IO::File not loaded
+
+=head3 Improved IPv6 support
+
+The C<Socket> module provides new affordances for IPv6,
+including implementations of the C<Socket::getaddrinfo()> and
+C<Socket::getnameinfo()> functions, along with related constants and a
+handful of new functions. See L<Socket>.
+
+=head3 DTrace probes now include package name
+
+The C<DTrace> probes now include an additional argument, C<arg3>, which contains
+the package the subroutine being entered or left was compiled in.
+
+For example, using the following DTrace script:
+
+ perl$target:::sub-entry
+ {
+ printf("%s::%s\n", copyinstr(arg0), copyinstr(arg3));
+ }
+
+and then running:
+
+ $ perl -e 'sub test { }; test'
+
+C<DTrace> will print:
+
+ main::test
+
+=head2 New C APIs
+
+See L</Internal Changes>.
+
+=head1 Security
+
+=head2 User-defined regular expression properties
+
+L<perlunicode/"User-Defined Character Properties"> documented that you can
+create custom properties by defining subroutines whose names begin with
+"In" or "Is". However, Perl did not actually enforce that naming
+restriction, so C<\p{foo::bar}> could call foo::bar() if it existed. The documented
+convention is now enforced.
+
+Also, Perl no longer allows tainted regular expressions to invoke a
+user-defined property. It simply dies instead [perl #82616].
+
+=head1 Incompatible Changes
+
+Perl 5.14.0 is not binary-compatible with any previous stable release.
+
+In addition to the sections that follow, see L</C API Changes>.
+
+=head2 Regular Expressions and String Escapes
+
+=head3 Inverted bracketed character classes and multi-character folds
+
+Some characters match a sequence of two or three characters in C</i>
+regular expression matching under Unicode rules. One example is
+C<LATIN SMALL LETTER SHARP S> which matches the sequence C<ss>.
+
+ 'ss' =~ /\A[\N{LATIN SMALL LETTER SHARP S}]\z/i # Matches
+
+This, however, can lead to very counter-intuitive results, especially
+when inverted. Because of this, Perl 5.14 does not use multi-character C</i>
+matching in inverted character classes.
+
+ 'ss' =~ /\A[^\N{LATIN SMALL LETTER SHARP S}]+\z/i # ???
+
+This should match any sequences of characters that aren't the C<SHARP S>
+nor what C<SHARP S> matches under C</i>. C<"s"> isn't C<SHARP S>, but
+Unicode says that C<"ss"> is what C<SHARP S> matches under C</i>. So
+which one "wins"? Do you fail the match because the string has C<ss> or
+accept it because it has an C<s> followed by another C<s>?
+
+Earlier releases of Perl did allow this multi-character matching,
+but due to bugs, it mostly did not work.
+
+=head3 \400-\777
+
+In certain circumstances, C<\400>-C<\777> in regexes have behaved
+differently than they behave in all other doublequote-like contexts.
+Since 5.10.1, Perl has issued a deprecation warning when this happens.
+Now, these literals behave the same in all doublequote-like contexts,
+namely to be equivalent to C<\x{100}>-C<\x{1FF}>, with no deprecation
+warning.
+
+Use of C<\400>-C<\777> in the command-line option B<-0> retain their
+conventional meaning. They slurp whole input files; previously, this
+was documented only for B<-0777>.
+
+Because of various ambiguities, you should use the new
+C<\o{...}> construct to represent characters in octal instead.
+
+=head3 Most C<\p{}> properties are now immune to case-insensitive matching
+
+For most Unicode properties, it doesn't make sense to have them match
+differently under C</i> case-insensitive matching. Doing so can lead
+to unexpected results and potential security holes. For example
+
+ m/\p{ASCII_Hex_Digit}+/i
+
+could previously match non-ASCII characters because of the Unicode
+matching rules (although there were several bugs with this). Now
+matching under C</i> gives the same results as non-C</i> matching except
+for those few properties where people have come to expect differences,
+namely the ones where casing is an integral part of their meaning, such
+as C<m/\p{Uppercase}/i> and C<m/\p{Lowercase}/i>, both of which match
+the same code points as matched by C<m/\p{Cased}/i>.
+Details are in L<perlrecharclass/Unicode Properties>.
+
+User-defined property handlers that need to match differently under C</i>
+must be changed to read the new boolean parameter passed to them, which
+is non-zero if case-insensitive matching is in effect and 0 otherwise.
+See L<perlunicode/User-Defined Character Properties>.
+
+=head3 \p{} implies Unicode semantics
+
+Specifying a Unicode property in the pattern indicates
+that the pattern is meant for matching according to Unicode rules, the way
+C<\N{I<NAME>}> does.
+
+=head3 Regular expressions retain their localeness when interpolated
+
+Regular expressions compiled under C<use locale> now retain this when
+interpolated into a new regular expression compiled outside a
+C<use locale>, and vice-versa.
+
+Previously, one regular expression interpolated into another inherited
+the localeness of the surrounding regex, losing whatever state it
+originally had. This is considered a bug fix, but may trip up code that
+has come to rely on the incorrect behaviour.
+
+=head3 Stringification of regexes has changed
+
+Default regular expression modifiers are now notated using
+C<(?^...)>. Code relying on the old stringification will fail.
+This is so that when new modifiers are added, such code won't
+have to keep changing each time this happens, because the stringification
+will automatically incorporate the new modifiers.
+
+Code that needs to work properly with both old- and new-style regexes
+can avoid the whole issue by using (for perls since 5.9.5; see L<re>):
+
+ use re qw(regexp_pattern);
+ my ($pat, $mods) = regexp_pattern($re_ref);
+
+If the actual stringification is important or older Perls need to be
+supported, you can use something like the following:
+
+ # Accept both old and new-style stringification
+ my $modifiers = (qr/foobar/ =~ /\Q(?^/) ? "^" : "-xism";
+
+And then use C<$modifiers> instead of C<-xism>.
+
+=head3 Run-time code blocks in regular expressions inherit pragmata
+
+Code blocks in regular expressions (C<(?{...})> and C<(??{...})>) previously
+did not inherit pragmata (strict, warnings, etc.) if the regular expression
+was compiled at run time as happens in cases like these two:
+
+ use re "eval";
+ $foo =~ $bar; # when $bar contains (?{...})
+ $foo =~ /$bar(?{ $finished = 1 })/;
+
+This bug has now been fixed, but code that relied on the buggy behaviour
+may need to be fixed to account for the correct behaviour.
+
+=head2 Stashes and Package Variables
+
+=head3 Localised tied hashes and arrays are no longed tied
+
+In the following:
+
+ tie @a, ...;
+ {
+ local @a;
+ # here, @a is a now a new, untied array
+ }
+ # here, @a refers again to the old, tied array
+
+Earlier versions of Perl incorrectly tied the new local array. This has
+now been fixed. This fix could however potentially cause a change in
+behaviour of some code.
+
+=head3 Stashes are now always defined
+
+C<defined %Foo::> now always returns true, even when no symbols have yet been
+defined in that package.
+
+This is a side-effect of removing a special-case kludge in the tokeniser,
+added for 5.10.0, to hide side-effects of changes to the internal storage of
+hashes. The fix drastically reduces hashes' memory overhead.
+
+Calling defined on a stash has been deprecated since 5.6.0, warned on
+lexicals since 5.6.0, and warned for stashes and other package
+variables since 5.12.0. C<defined %hash> has always exposed an
+implementation detail: emptying a hash by deleting all entries from it does
+not make C<defined %hash> false. Hence C<defined %hash> is not valid code to
+determine whether an arbitrary hash is empty. Instead, use the behaviour
+of an empty C<%hash> always returning false in scalar context.
+
+=head3 Clearing stashes
+
+Stash list assignment C<%foo:: = ()> used to make the stash temporarily
+anonymous while it was being emptied. Consequently, any of its
+subroutines referenced elsewhere would become anonymous, showing up as
+"(unknown)" in C<caller>. They now retain their package names such that
+C<caller> returns the original sub name if there is still a reference
+to its typeglob and "foo::__ANON__" otherwise [perl #79208].
+
+=head3 Dereferencing typeglobs
+
+If you assign a typeglob to a scalar variable:
+
+ $glob = *foo;
+
+the glob that is copied to C<$glob> is marked with a special flag
+indicating that the glob is just a copy. This allows subsequent
+assignments to C<$glob> to overwrite the glob. The original glob,
+however, is immutable.
+
+Some Perl operators did not distinguish between these two types of globs.
+This would result in strange behaviour in edge cases: C<untie $scalar>
+would not untie the scalar if the last thing assigned to it was a glob
+(because it treated it as C<untie *$scalar>, which unties a handle).
+Assignment to a glob slot (such as C<*$glob = \@some_array>) would simply
+assign C<\@some_array> to C<$glob>.
+
+To fix this, the C<*{}> operator (including its C<*foo> and C<*$foo> forms)
+has been modified to make a new immutable glob if its operand is a glob
+copy. This allows operators that make a distinction between globs and
+scalars to be modified to treat only immutable globs as globs. (C<tie>,
+C<tied> and C<untie> have been left as they are for compatibility's sake,
+but will warn. See L</Deprecations>.)
+
+This causes an incompatible change in code that assigns a glob to the
+return value of C<*{}> when that operator was passed a glob copy. Take the
+following code, for instance:
+
+ $glob = *foo;
+ *$glob = *bar;
+
+The C<*$glob> on the second line returns a new immutable glob. That new
+glob is made an alias to C<*bar>. Then it is discarded. So the second
+assignment has no effect.
+
+See L<http://rt.perl.org/rt3/Public/Bug/Display.html?id=77810> for
+more detail.
+
+=head3 Magic variables outside the main package
+
+In previous versions of Perl, magic variables like C<$!>, C<%SIG>, etc. would
+"leak" into other packages. So C<%foo::SIG> could be used to access signals,
+C<${"foo::!"}> (with strict mode off) to access C's C<errno>, etc.
+
+This was a bug, or an "unintentional" feature, which caused various ill effects,
+such as signal handlers being wiped when modules were loaded, etc.
+
+This has been fixed (or the feature has been removed, depending on how you see
+it).
+
+=head3 local($_) strips all magic from $_
+
+local() on scalar variables gives them a new value but keeps all
+their magic intact. This has proven problematic for the default
+scalar variable $_, where L<perlsub> recommends that any subroutine
+that assigns to $_ should first localize it. This would throw an
+exception if $_ is aliased to a read-only variable, and could in general have
+various unintentional side-effects.
+
+Therefore, as an exception to the general rule, local($_) will not
+only assign a new value to $_, but also remove all existing magic from
+it as well.
+
+=head3 Parsing of package and variable names
+
+Parsing the names of packages and package variables has changed:
+multiple adjacent pairs of colons, as in C<foo::::bar>, are now all
+treated as package separators.
+
+Regardless of this change, the exact parsing of package separators has
+never been guaranteed and is subject to change in future Perl versions.
+
+=head2 Changes to Syntax or to Perl Operators
+
+=head3 C<given> return values
+
+C<given> blocks now return the last evaluated
+expression, or an empty list if the block was exited by C<break>. Thus you
+can now write:
+
+ my $type = do {
+ given ($num) {
+ break when undef;
+ "integer" when /^[+-]?[0-9]+$/;
+ "float" when /^[+-]?[0-9]+(?:\.[0-9]+)?$/;
+ "unknown";
+ }
+ };
+
+See L<perlsyn/Return value> for details.
+
+=head3 Change in parsing of certain prototypes
+
+Functions declared with the following prototypes now behave correctly as unary
+functions:
+
+ *
+ \$ \% \@ \* \&
+ \[...]
+ ;$ ;*
+ ;\$ ;\% etc.
+ ;\[...]
+
+Due to this bug fix [perl #75904], functions
+using the C<(*)>, C<(;$)> and C<(;*)> prototypes
+are parsed with higher precedence than before. So
+in the following example:
+
+ sub foo(;$);
+ foo $a < $b;
+
+the second line is now parsed correctly as C<< foo($a) < $b >>, rather than
+C<< foo($a < $b) >>. This happens when one of these operators is used in
+an unparenthesised argument:
+
+ < > <= >= lt gt le ge
+ == != <=> eq ne cmp ~~
+ &
+ | ^
+ &&
+ || //
+ .. ...
+ ?:
+ = += -= *= etc.
+ , =>
+
+=head3 Smart-matching against array slices
+
+Previously, the following code resulted in a successful match:
+
+ my @a = qw(a y0 z);
+ my @b = qw(a x0 z);
+ @a[0 .. $#b] ~~ @b;
+
+This odd behaviour has now been fixed [perl #77468].
+
+=head3 Negation treats strings differently from before
+
+The unary negation operator, C<->, now treats strings that look like numbers
+as numbers [perl #57706].
+
+=head3 Negative zero
+
+Negative zero (-0.0), when converted to a string, now becomes "0" on all
+platforms. It used to become "-0" on some, but "0" on others.
+
+If you still need to determine whether a zero is negative, use
+C<sprintf("%g", $zero) =~ /^-/> or the L<Data::Float> module on CPAN.
+
+=head3 C<:=> is now a syntax error
+
+Previously C<my $pi := 4> was exactly equivalent to C<my $pi : = 4>,
+with the C<:> being treated as the start of an attribute list, ending before
+the C<=>. The use of C<:=> to mean C<: => was deprecated in 5.12.0, and is
+now a syntax error. This allows future use of C<:=> as a new token.
+
+Outside the core's tests for it, we find no Perl 5 code on CPAN
+using this construction, so we believe that this change will have
+little impact on real-world codebases.
+
+If it is absolutely necessary to have empty attribute lists (for example,
+because of a code generator), simply avoid the error by adding a space before
+the C<=>.
+
+=head3 Change in the parsing of identifiers
+
+Characters outside the Unicode "XIDStart" set are no longer allowed at the
+beginning of an identifier. This means that certain accents and marks
+that normally follow an alphabetic character may no longer be the first
+character of an identifier.
+
+=head2 Threads and Processes
+
+=head3 Directory handles not copied to threads
+
+On systems other than Windows that do not have
+a C<fchdir> function, newly-created threads no
+longer inherit directory handles from their parent threads. Such programs
+would usually have crashed anyway [perl #75154].
+
+=head3 C<close> on shared pipes
+
+To avoid deadlocks, the C<close> function no longer waits for the
+child process to exit if the underlying file descriptor is still
+in use by another thread. It returns true in such cases.
+
+=head3 fork() emulation will not wait for signalled children
+
+On Windows parent processes would not terminate until all forked
+children had terminated first. However, C<kill("KILL", ...)> is
+inherently unstable on pseudo-processes, and C<kill("TERM", ...)>
+might not get delivered if the child is blocked in a system call.
+
+To avoid the deadlock and still provide a safe mechanism to terminate
+the hosting process, Perl now no longer waits for children that
+have been sent a SIGTERM signal. It is up to the parent process to
+waitpid() for these children if child-cleanup processing must be
+allowed to finish. However, it is also then the responsibility of the
+parent to avoid the deadlock by making sure the child process
+can't be blocked on I/O.
+
+See L<perlfork> for more information about the fork() emulation on
+Windows.
+
+=head2 Configuration
+
+=head3 Naming fixes in Policy_sh.SH may invalidate Policy.sh
+
+Several long-standing typos and naming confusions in F<Policy_sh.SH> have
+been fixed, standardizing on the variable names used in F<config.sh>.
+
+This will change the behaviour of F<Policy.sh> if you happen to have been
+accidentally relying on its incorrect behaviour.
+
+=head3 Perl source code is read in text mode on Windows
+
+Perl scripts used to be read in binary mode on Windows for the benefit
+of the L<ByteLoader> module (which is no longer part of core Perl). This
+had the side-effect of breaking various operations on the C<DATA> filehandle,
+including seek()/tell(), and even simply reading from C<DATA> after filehandles
+have been flushed by a call to system(), backticks, fork() etc.
+
+The default build options for Windows have been changed to read Perl source
+code on Windows in text mode now. L<ByteLoader> will (hopefully) be updated on
+CPAN to automatically handle this situation [perl #28106].
+
+=head1 Deprecations
+
+See also L</Deprecated C APIs>.
+
+=head2 Omitting a space between a regular expression and subsequent word
+
+Omitting the space between a regular expression operator or
+its modifiers and the following word is deprecated. For
+example, C<< m/foo/sand $bar >> is for now still parsed
+as C<< m/foo/s and $bar >>, but will now issue a warning.
+
+=head2 C<\cI<X>>
+
+The backslash-c construct was designed as a way of specifying
+non-printable characters, but there were no restrictions (on ASCII
+platforms) on what the character following the C<c> could be. Now,
+a deprecation warning is raised if that character isn't an ASCII character.
+Also, a deprecation warning is raised for C<"\c{"> (which is the same
+as simply saying C<";">).
+
+=head2 C<"\b{"> and C<"\B{">
+
+In regular expressions, a literal C<"{"> immediately following a C<"\b">
+(not in a bracketed character class) or a C<"\B{"> is now deprecated
+to allow for its future use by Perl itself.
+
+=head2 Perl 4-era .pl libraries
+
+Perl bundles a handful of library files that predate Perl 5.
+This bundling is now deprecated for most of these files, which are now
+available from CPAN. The affected files now warn when run, if they were
+installed as part of the core.
+
+This is a mandatory warning, not obeying B<-X> or lexical warning bits.
+The warning is modelled on that supplied by F<deprecate.pm> for
+deprecated-in-core F<.pm> libraries. It points to the specific CPAN
+distribution that contains the F<.pl> libraries. The CPAN versions, of
+course, do not generate the warning.
+
+=head2 List assignment to C<$[>
+
+Assignment to C<$[> was deprecated and started to give warnings in
+Perl version 5.12.0. This version of Perl (5.14) now also emits a warning
+when assigning to C<$[> in list context. This fixes an oversight in 5.12.0.
+
+=head2 Use of qw(...) as parentheses
+
+Historically the parser fooled itself into thinking that C<qw(...)> literals
+were always enclosed in parentheses, and as a result you could sometimes omit
+parentheses around them:
+
+ for $x qw(a b c) { ... }
+
+The parser no longer lies to itself in this way. Wrap the list literal in
+parentheses like this:
+
+ for $x (qw(a b c)) { ... }
+
+This is being deprecated because the parentheses in C<for $i (1,2,3) { ... }>
+are not part of expression syntax. They are part of the statement
+syntax, with the C<for> statement wanting literal parentheses.
+The synthetic parentheses that a C<qw> expression acquired were only
+intended to be treated as part of expression syntax.
+
+Note that this does not change the behaviour of cases like:
+
+ use POSIX qw(setlocale localeconv);
+ our @EXPORT = qw(foo bar baz);
+
+where parentheses were never required around the expression.
+
+=head2 C<\N{BELL}>
+
+This is because Unicode is using that name for a different character.
+See L</Unicode Version 6.0 is now supported (mostly)> for more
+explanation.
+
+=head2 C<?PATTERN?>
+
+C<?PATTERN?> (without the initial C<m>) has been deprecated and now produces
+a warning. This is to allow future use of C<?> in new operators.
+The match-once functionality is still available as C<m?PATTERN?>.
+
+=head2 Tie functions on scalars holding typeglobs
+
+Calling a tie function (C<tie>, C<tied>, C<untie>) with a scalar argument
+acts on a filehandle if the scalar happens to hold a typeglob.
+
+This is a long-standing bug that will be removed in Perl 5.16, as
+there is currently no way to tie the scalar itself when it holds
+a typeglob, and no way to untie a scalar that has had a typeglob
+assigned to it.
+
+Now there is a deprecation warning whenever a tie
+function is used on a handle without an explicit C<*>.
+
+=head2 User-defined case-mapping
+
+This feature is being deprecated due to its many issues, as documented in
+L<perlunicode/User-Defined Case Mappings (for serious hackers only)>.
+This feature will be removed in Perl 5.16. Instead use the CPAN module
+L<Unicode::Casing>, which provides improved functionality.
+
+=head2 Deprecated modules
+
+The following module will be removed from the core distribution in a
+future release, and should be installed from CPAN instead. Distributions
+on CPAN that require this should add it to their prerequisites. The
+core version of these module now issues a deprecation warning.
+
+If you ship a packaged version of Perl, either alone or as part of a
+larger system, then you should carefully consider the repercussions of
+core module deprecations. You may want to consider shipping your default
+build of Perl with a package for the deprecated module that
+installs into C<vendor> or C<site> Perl library directories. This will
+inhibit the deprecation warnings.
+
+Alternatively, you may want to consider patching F<lib/deprecate.pm>
+to provide deprecation warnings specific to your packaging system
+or distribution of Perl, consistent with how your packaging system
+or distribution manages a staged transition from a release where the
+installation of a single package provides the given functionality, to
+a later release where the system administrator needs to know to install
+multiple packages to get that same functionality.
+
+You can silence these deprecation warnings by installing the module
+in question from CPAN. To install the latest version of it by role
+rather than by name, just install C<Task::Deprecations::5_14>.
+
+=over
+
+=item L<Devel::DProf>
+
+We strongly recommend that you install and use L<Devel::NYTProf> instead
+of L<Devel::DProf>, as L<Devel::NYTProf> offers significantly
+improved profiling and reporting.
+
+=back
+
+=head1 Performance Enhancements
+
+=head2 "Safe signals" optimisation
+
+Signal dispatch has been moved from the runloop into control ops.
+This should give a few percent speed increase, and eliminates nearly
+all the speed penalty caused by the introduction of "safe signals"
+in 5.8.0. Signals should still be dispatched within the same
+statement as they were previously. If this does I<not> happen, or
+if you find it possible to create uninterruptible loops, this is a
+bug, and reports are encouraged of how to recreate such issues.
+
+=head2 Optimisation of shift() and pop() calls without arguments
+
+Two fewer OPs are used for shift() and pop() calls with no argument (with
+implicit C<@_>). This change makes shift() 5% faster than C<shift @_>
+on non-threaded perls, and 25% faster on threaded ones.
+
+=head2 Optimisation of regexp engine string comparison work
+
+The C<foldEQ_utf8> API function for case-insensitive comparison of strings (which
+is used heavily by the regexp engine) was substantially refactored and
+optimised -- and its documentation much improved as a free bonus.
+
+=head2 Regular expression compilation speed-up
+
+Compiling regular expressions has been made faster when upgrading
+the regex to utf8 is necessary but this isn't known when the compilation begins.
+
+=head2 String appending is 100 times faster
+
+When doing a lot of string appending, perls built to use the system's
+C<malloc> could end up allocating a lot more memory than needed in a
+inefficient way.
+
+C<sv_grow>, the function used to allocate more memory if necessary
+when appending to a string, has been taught to round up the memory
+it requests to a certain geometric progression, making it much faster on
+certain platforms and configurations. On Win32, it's now about 100 times
+faster.
+
+=head2 Eliminate C<PL_*> accessor functions under ithreads
+
+When C<MULTIPLICITY> was first developed, and interpreter state moved into
+an interpreter struct, thread- and interpreter-local C<PL_*> variables
+were defined as macros that called accessor functions (returning the
+address of the value) outside the Perl core. The intent was to allow
+members within the interpreter struct to change size without breaking
+binary compatibility, so that bug fixes could be merged to a maintenance
+branch that necessitated such a size change. This mechanism was redundant
+and penalised well-behaved code. It has been removed.
+
+=head2 Freeing weak references
+
+When there are many weak references to an object, freeing that object
+can under some circumstances take O(I<NE<0xB2>>) time to free, where
+I<N> is the number of references. The circumstances in which this can happen
+have been reduced [perl #75254]
+
+=head2 Lexical array and hash assignments
+
+An earlier optimisation to speed up C<my @array = ...> and
+C<my %hash = ...> assignments caused a bug and was disabled in Perl 5.12.0.
+
+Now we have found another way to speed up these assignments [perl #82110].
+
+=head2 C<@_> uses less memory
+
+Previously, C<@_> was allocated for every subroutine at compile time with
+enough space for four entries. Now this allocation is done on demand when
+the subroutine is called [perl #72416].
+
+=head2 Size optimisations to SV and HV structures
+
+C<xhv_fill> has been eliminated from C<struct xpvhv>, saving 1 IV per hash and
+on some systems will cause C<struct xpvhv> to become cache-aligned. To avoid
+this memory saving causing a slowdown elsewhere, boolean use of C<HvFILL>
+now calls C<HvTOTALKEYS> instead (which is equivalent), so while the fill
+data when actually required are now calculated on demand, cases when
+this needs to be done should be rare.
+
+The order of structure elements in SV bodies has changed. Effectively,
+the NV slot has swapped location with STASH and MAGIC. As all access to
+SV members is via macros, this should be completely transparent. This
+change allows the space saving for PVHVs documented above, and may reduce
+the memory allocation needed for PVIVs on some architectures.
+
+C<XPV>, C<XPVIV>, and C<XPVNV> now allocate only the parts of the C<SV> body
+they actually use, saving some space.
+
+Scalars containing regular expressions now allocate only the part of the C<SV>
+body they actually use, saving some space.
+
+=head2 Memory consumption improvements to Exporter
+
+The C<@EXPORT_FAIL> AV is no longer created unless needed, hence neither is
+the typeglob backing it. This saves about 200 bytes for every package that
+uses Exporter but doesn't use this functionality.
+
+=head2 Memory savings for weak references
+
+For weak references, the common case of just a single weak reference
+per referent has been optimised to reduce the storage required. In this
+case it saves the equivalent of one small Perl array per referent.
+
+=head2 C<%+> and C<%-> use less memory
+
+The bulk of the C<Tie::Hash::NamedCapture> module used to be in the Perl
+core. It has now been moved to an XS module to reduce overhead for
+programs that do not use C<%+> or C<%->.
+
+=head2 Multiple small improvements to threads
+
+The internal structures of threading now make fewer API calls and fewer
+allocations, resulting in noticeably smaller object code. Additionally,
+many thread context checks have been deferred so they're done only
+as needed (although this is only possible for non-debugging builds).
+
+=head2 Adjacent pairs of nextstate opcodes are now optimized away
+
+Previously, in code such as
+
+ use constant DEBUG => 0;
+
+ sub GAK {
+ warn if DEBUG;
+ print "stuff\n";
+ }
+
+the ops for C<warn if DEBUG> would be folded to a C<null> op (C<ex-const>), but
+the C<nextstate> op would remain, resulting in a runtime op dispatch of
+C<nextstate>, C<nextstate>, etc.
+
+The execution of a sequence of C<nextstate> ops is indistinguishable from just
+the last C<nextstate> op so the peephole optimizer now eliminates the first of
+a pair of C<nextstate> ops except when the first carries a label, since labels
+must not be eliminated by the optimizer, and label usage isn't conclusively known
+at compile time.
+
+=head1 Modules and Pragmata
+
+=head2 New Modules and Pragmata
+
+=over 4
+
+=item *
+
+L<CPAN::Meta::YAML> 0.003 has been added as a dual-life module. It supports a
+subset of YAML sufficient for reading and writing F<META.yml> and F<MYMETA.yml> files
+included with CPAN distributions or generated by the module installation
+toolchain. It should not be used for any other general YAML parsing or
+generation task.
+
+=item *
+
+L<CPAN::Meta> version 2.110440 has been added as a dual-life module. It
+provides a standard library to read, interpret and write CPAN distribution
+metadata files (like F<META.json> and F<META.yml)> that describe a
+distribution, its contents, and the requirements for building it and
+installing it. The latest CPAN distribution metadata specification is
+included as L<CPAN::Meta::Spec> and notes on changes in the specification
+over time are given in L<CPAN::Meta::History>.
+
+=item *
+
+L<HTTP::Tiny> 0.012 has been added as a dual-life module. It is a very
+small, simple HTTP/1.1 client designed for simple GET requests and file
+mirroring. It has been added so that F<CPAN.pm> and L<CPANPLUS> can
+"bootstrap" HTTP access to CPAN using pure Perl without relying on external
+binaries like L<curl(1)> or L<wget(1)>.
+
+=item *
+
+L<JSON::PP> 2.27105 has been added as a dual-life module to allow CPAN
+clients to read F<META.json> files in CPAN distributions.
+
+=item *
+
+L<Module::Metadata> 1.000004 has been added as a dual-life module. It gathers
+package and POD information from Perl module files. It is a standalone module
+based on L<Module::Build::ModuleInfo> for use by other module installation
+toolchain components. L<Module::Build::ModuleInfo> has been deprecated in
+favor of this module instead.
+
+=item *
+
+L<Perl::OSType> 1.002 has been added as a dual-life module. It maps Perl
+operating system names (like "dragonfly" or "MSWin32") to more generic types
+with standardized names (like "Unix" or "Windows"). It has been refactored
+out of L<Module::Build> and L<ExtUtils::CBuilder> and consolidates such mappings into
+a single location for easier maintenance.
+
+=item *
+
+The following modules were added by the L<Unicode::Collate>
+upgrade. See below for details.
+
+L<Unicode::Collate::CJK::Big5>
+
+L<Unicode::Collate::CJK::GB2312>
+
+L<Unicode::Collate::CJK::JISX0208>
+
+L<Unicode::Collate::CJK::Korean>
+
+L<Unicode::Collate::CJK::Pinyin>
+
+L<Unicode::Collate::CJK::Stroke>
+
+=item *
+
+L<Version::Requirements> version 0.101020 has been added as a dual-life
+module. It provides a standard library to model and manipulates module
+prerequisites and version constraints defined in L<CPAN::Meta::Spec>.
+
+=back
+
+=head2 Updated Modules and Pragma
+
+=over 4
+
+=item *
+
+L<attributes> has been upgraded from version 0.12 to 0.14.
+
+=item *
+
+L<Archive::Extract> has been upgraded from version 0.38 to 0.48.
+
+Updates since 0.38 include: a safe print method that guards
+L<Archive::Extract> from changes to C<$\>; a fix to the tests when run in core
+Perl; support for TZ files; a modification for the lzma
+logic to favour L<IO::Uncompress::Unlzma>; and a fix
+for an issue with NetBSD-current and its new L<unzip(1)>
+executable.
+
+=item *
+
+L<Archive::Tar> has been upgraded from version 1.54 to 1.76.
+
+Important changes since 1.54 include the following:
+
+=over
+
+=item *
+
+Compatibility with busybox implementations of L<tar(1)>.
+
+=item *
+
+A fix so that write() and create_archive()
+close only filehandles they themselves opened.
+
+=item *
+
+A bug was fixed regarding the exit code of extract_archive.
+
+=item *
+
+The L<ptar(1)> utility has a new option to allow safe creation of
+tarballs without world-writable files on Windows, allowing those
+archives to be uploaded to CPAN.
+
+=item *
+
+A new L<ptargrep(1)> utility for using regular expressions against
+the contents of files in a tar archive.
+
+=item *
+
+L<pax> extended headers are now skipped.
+
+=back
+
+=item *
+
+L<Attribute::Handlers> has been upgraded from version 0.87 to 0.89.
+
+=item *
+
+L<autodie> has been upgraded from version 2.06_01 to 2.1001.
+
+=item *
+
+L<AutoLoader> has been upgraded from version 5.70 to 5.71.
+
+=item *
+
+The L<B> module has been upgraded from version 1.23 to 1.29.
+
+It no longer crashes when taking apart a C<y///> containing characters
+outside the octet range or compiled in a C<use utf8> scope.
+
+The size of the shared object has been reduced by about 40%, with no
+reduction in functionality.
+
+=item *
+
+L<B::Concise> has been upgraded from version 0.78 to 0.83.
+
+L<B::Concise> marks rv2sv(), rv2av(), and rv2hv() ops with the new
+C<OPpDEREF> flag as "DREFed".
+
+It no longer produces mangled output with the B<-tree> option
+[perl #80632].
+
+=item *
+
+L<B::Debug> has been upgraded from version 1.12 to 1.16.
+
+=item *
+
+L<B::Deparse> has been upgraded from version 0.96 to 1.03.
+
+The deparsing of a C<nextstate> op has changed when it has both a
+change of package relative to the previous nextstate, or a change of
+C<%^H> or other state and a label. The label was previously emitted
+first, but is now emitted last (5.12.1).
+
+The C<no 5.13.2> or similar form is now correctly handled by L<B::Deparse>
+(5.12.3).
+
+L<B::Deparse> now properly handles the code that applies a conditional
+pattern match against implicit C<$_> as it was fixed in [perl #20444].
+
+Deparsing of C<our> followed by a variable with funny characters
+(as permitted under the C<use utf8> pragma) has also been fixed [perl #33752].
+
+=item *
+
+L<B::Lint> has been upgraded from version 1.11_01 to 1.13.
+
+=item *
+
+L<base> has been upgraded from version 2.15 to 2.16.
+
+=item *
+
+L<Benchmark> has been upgraded from version 1.11 to 1.12.
+
+=item *
+
+L<bignum> has been upgraded from version 0.23 to 0.27.
+
+=item *
+
+L<Carp> has been upgraded from version 1.15 to 1.20.
+
+L<Carp> now detects incomplete L<caller()|perlfunc/"caller EXPR">
+overrides and avoids using bogus C<@DB::args>. To provide backtraces,
+Carp relies on particular behaviour of the caller() builtin.
+L<Carp> now detects if other code has overridden this with an
+incomplete implementation, and modifies its backtrace accordingly.
+Previously incomplete overrides would cause incorrect values in
+backtraces (best case), or obscure fatal errors (worst case).
+
+This fixes certain cases of "Bizarre copy of ARRAY" caused by modules
+overriding caller() incorrectly (5.12.2).
+
+It now also avoids using regular expressions that cause Perl to
+load its Unicode tables, so as to avoid the "BEGIN not safe after
+errors" error that ensue if there has been a syntax error
+[perl #82854].
+
+=item *
+
+L<CGI> has been upgraded from version 3.48 to 3.52.
+
+This provides the following security fixes: the MIME boundary in
+multipart_init() is now random and the handling of
+newlines embedded in header values has been improved.
+
+=item *
+
+L<Compress::Raw::Bzip2> has been upgraded from version 2.024 to 2.033.
+
+It has been updated to use L<bzip2(1)> 1.0.6.
+
+=item *
+
+L<Compress::Raw::Zlib> has been upgraded from version 2.024 to 2.033.
+
+=item *
+
+L<constant> has been upgraded from version 1.20 to 1.21.
+
+Unicode constants work once more. They have been broken since Perl 5.10.0
+[CPAN RT #67525].
+
+=item *
+
+L<CPAN> has been upgraded from version 1.94_56 to 1.9600.
+
+Major highlights:
+
+=over 4
+
+=item * much less configuration dialog hassle
+
+=item * support for F<META/MYMETA.json>
+
+=item * support for L<local::lib>
+
+=item * support for L<HTTP::Tiny> to reduce the dependency on FTP sites
+
+=item * automatic mirror selection
+
+=item * iron out all known bugs in configure_requires
+
+=item * support for distributions compressed with L<bzip2(1)>
+
+=item * allow F<Foo/Bar.pm> on the command line to mean C<Foo::Bar>
+
+=back
+
+=item *
+
+L<CPANPLUS> has been upgraded from version 0.90 to 0.9103.
+
+A change to F<cpanp-run-perl>
+resolves L<RT #55964|http://rt.cpan.org/Public/Bug/Display.html?id=55964>
+and L<RT #57106|http://rt.cpan.org/Public/Bug/Display.html?id=57106>, both
+of which related to failures to install distributions that use
+C<Module::Install::DSL> (5.12.2).
+
+A dependency on L<Config> was not recognised as a
+core module dependency. This has been fixed.
+
+L<CPANPLUS> now includes support for F<META.json> and F<MYMETA.json>.
+
+=item *
+
+L<CPANPLUS::Dist::Build> has been upgraded from version 0.46 to 0.54.
+
+=item *
+
+L<Data::Dumper> has been upgraded from version 2.125 to 2.130_02.
+
+The indentation used to be off when C<$Data::Dumper::Terse> was set. This
+has been fixed [perl #73604].
+
+This upgrade also fixes a crash when using custom sort functions that might
+cause the stack to change [perl #74170].
+
+L<Dumpxs> no longer crashes with globs returned by C<*$io_ref>
+[perl #72332].
+
+=item *
+
+L<DB_File> has been upgraded from version 1.820 to 1.821.
+
+=item *
+
+L<DBM_Filter> has been upgraded from version 0.03 to 0.04.
+
+=item *
+
+L<Devel::DProf> has been upgraded from version 20080331.00 to 20110228.00.
+
+Merely loading L<Devel::DProf> now no longer triggers profiling to start.
+Both C<use Devel::DProf> and C<perl -d:DProf ...> behave as before and start
+the profiler.
+
+B<NOTE>: L<Devel::DProf> is deprecated and will be removed from a future
+version of Perl. We strongly recommend that you install and use
+L<Devel::NYTProf> instead, as it offers significantly improved
+profiling and reporting.
+
+=item *
+
+L<Devel::Peek> has been upgraded from version 1.04 to 1.07.
+
+=item *
+
+L<Devel::SelfStubber> has been upgraded from version 1.03 to 1.05.
+
+=item *
+
+L<diagnostics> has been upgraded from version 1.19 to 1.22.
+
+It now renders pod links slightly better, and has been taught to find
+descriptions for messages that share their descriptions with other
+messages.
+
+=item *
+
+L<Digest::MD5> has been upgraded from version 2.39 to 2.51.
+
+It is now safe to use this module in combination with threads.
+
+=item *
+
+L<Digest::SHA> has been upgraded from version 5.47 to 5.61.
+
+L<shasum> now more closely mimics L<sha1sum(1)>/L<md5sum(1)>.
+
+L<Addfile> accepts all POSIX filenames.
+
+New SHA-512/224 and SHA-512/256 transforms (ref. NIST Draft FIPS 180-4
+[February 2011])
+
+=item *
+
+L<DirHandle> has been upgraded from version 1.03 to 1.04.
+
+=item *
+
+L<Dumpvalue> has been upgraded from version 1.13 to 1.16.
+
+=item *
+
+L<DynaLoader> has been upgraded from version 1.10 to 1.13.
+
+It fixes a buffer overflow when passed a very long file name.
+
+It no longer inherits from L<AutoLoader>; hence it no longer
+produces weird error messages for unsuccessful method calls on classes that
+inherit from L<DynaLoader> [perl #84358].
+
+=item *
+
+L<Encode> has been upgraded from version 2.39 to 2.42.
+
+Now, all 66 Unicode non-characters are treated the same way U+FFFF has
+always been treated: in cases when it was disallowed, all 66 are
+disallowed, and in cases where it warned, all 66 warn.
+
+=item *
+
+L<Env> has been upgraded from version 1.01 to 1.02.
+
+=item *
+
+L<Errno> has been upgraded from version 1.11 to 1.13.
+
+The implementation of L<Errno> has been refactored to use about 55% less memory.
+
+On some platforms with unusual header files, like Win32 L<gcc(1)> using C<mingw64>
+headers, some constants that weren't actually error numbers have been exposed
+by L<Errno>. This has been fixed [perl #77416].
+
+=item *
+
+L<Exporter> has been upgraded from version 5.64_01 to 5.64_03.
+
+Exporter no longer overrides C<$SIG{__WARN__}> [perl #74472]
+
+=item *
+
+L<ExtUtils::CBuilder> has been upgraded from version 0.27 to 0.280203.
+
+=item *
+
+L<ExtUtils::Command> has been upgraded from version 1.16 to 1.17.
+
+=item *
+
+L<ExtUtils::Constant> has been upgraded from 0.22 to 0.23.
+
+The L<AUTOLOAD> helper code generated by C<ExtUtils::Constant::ProxySubs>
+can now croak() for missing constants, or generate a complete C<AUTOLOAD>
+subroutine in XS, allowing simplification of many modules that use it
+(L<Fcntl>, L<File::Glob>, L<GDBM_File>, L<I18N::Langinfo>, L<POSIX>,
+L<Socket>).
+
+L<ExtUtils::Constant::ProxySubs> can now optionally push the names of all
+constants onto the package's C<@EXPORT_OK>.
+
+=item *
+
+L<ExtUtils::Install> has been upgraded from version 1.55 to 1.56.
+
+=item *
+
+L<ExtUtils::MakeMaker> has been upgraded from version 6.56 to 6.57_05.
+
+=item *
+
+L<ExtUtils::Manifest> has been upgraded from version 1.57 to 1.58.
+
+=item *
+
+L<ExtUtils::ParseXS> has been upgraded from version 2.21 to 2.2210.
+
+=item *
+
+L<Fcntl> has been upgraded from version 1.06 to 1.11.
+
+=item *
+
+L<File::Basename> has been upgraded from version 2.78 to 2.82.
+
+=item *
+
+L<File::CheckTree> has been upgraded from version 4.4 to 4.41.
+
+=item *
+
+L<File::Copy> has been upgraded from version 2.17 to 2.21.
+
+=item *
+
+L<File::DosGlob> has been upgraded from version 1.01 to 1.04.
+
+It allows patterns containing literal parentheses: they no longer need to
+be escaped. On Windows, it no longer
+adds an extra F<./> to file names
+returned when the pattern is a relative glob with a drive specification,
+like F<C:*.pl> [perl #71712].
+
+=item *
+
+L<File::Fetch> has been upgraded from version 0.24 to 0.32.
+
+L<HTTP::Lite> is now supported for the "http" scheme.
+
+The L<fetch(1)> utility is supported on FreeBSD, NetBSD, and
+Dragonfly BSD for the C<http> and C<ftp> schemes.
+
+=item *
+
+L<File::Find> has been upgraded from version 1.15 to 1.19.
+
+It improves handling of backslashes on Windows, so that paths like
+F<C:\dir\/file> are no longer generated [perl #71710].
+
+=item *
+
+L<File::Glob> has been upgraded from version 1.07 to 1.12.
+
+=item *
+
+L<File::Spec> has been upgraded from version 3.31 to 3.33.
+
+Several portability fixes were made in L<File::Spec::VMS>: a colon is now
+recognized as a delimiter in native filespecs; caret-escaped delimiters are
+recognized for better handling of extended filespecs; catpath() returns
+an empty directory rather than the current directory if the input directory
+name is empty; and abs2rel() properly handles Unix-style input (5.12.2).
+
+=item *
+
+L<File::stat> has been upgraded from 1.02 to 1.05.
+
+The C<-x> and C<-X> file test operators now work correctly when run
+by the superuser.
+
+=item *
+
+L<Filter::Simple> has been upgraded from version 0.84 to 0.86.
+
+=item *
+
+L<GDBM_File> has been upgraded from 1.10 to 1.14.
+
+This fixes a memory leak when DBM filters are used.
+
+=item *
+
+L<Hash::Util> has been upgraded from 0.07 to 0.11.
+
+L<Hash::Util> no longer emits spurious "uninitialized" warnings when
+recursively locking hashes that have undefined values [perl #74280].
+
+=item *
+
+L<Hash::Util::FieldHash> has been upgraded from version 1.04 to 1.09.
+
+=item *
+
+L<I18N::Collate> has been upgraded from version 1.01 to 1.02.
+
+=item *
+
+L<I18N::Langinfo> has been upgraded from version 0.03 to 0.08.
+
+langinfo() now defaults to using C<$_> if there is no argument given, just
+as the documentation has always claimed.
+
+=item *
+
+L<I18N::LangTags> has been upgraded from version 0.35 to 0.35_01.
+
+=item *
+
+L<if> has been upgraded from version 0.05 to 0.0601.
+
+=item *
+
+L<IO> has been upgraded from version 1.25_02 to 1.25_04.
+
+This version of L<IO> includes a new L<IO::Select>, which now allows L<IO::Handle>
+objects (and objects in derived classes) to be removed from an L<IO::Select> set
+even if the underlying file descriptor is closed or invalid.
+
+=item *
+
+L<IPC::Cmd> has been upgraded from version 0.54 to 0.70.
+
+Resolves an issue with splitting Win32 command lines. An argument
+consisting of the single character "0" used to be omitted (CPAN RT #62961).
+
+=item *
+
+L<IPC::Open3> has been upgraded from 1.05 to 1.09.
+
+open3() now produces an error if the C<exec> call fails, allowing this
+condition to be distinguished from a child process that exited with a
+non-zero status [perl #72016].
+
+The internal xclose() routine now knows how to handle file descriptors as
+documented, so duplicating C<STDIN> in a child process using its file
+descriptor now works [perl #76474].
+
+=item *
+
+L<IPC::SysV> has been upgraded from version 2.01 to 2.03.
+
+=item *
+
+L<lib> has been upgraded from version 0.62 to 0.63.
+
+=item *
+
+L<Locale::Maketext> has been upgraded from version 1.14 to 1.19.
+
+L<Locale::Maketext> now supports external caches.
+
+This upgrade also fixes an infinite loop in
+C<Locale::Maketext::Guts::_compile()> when
+working with tainted values (CPAN RT #40727).
+
+C<< ->maketext >> calls now back up and restore C<$@> so error
+messages are not suppressed (CPAN RT #34182).
+
+=item *
+
+L<Log::Message> has been upgraded from version 0.02 to 0.04.
+
+=item *
+
+L<Log::Message::Simple> has been upgraded from version 0.06 to 0.08.
+
+=item *
+
+L<Math::BigInt> has been upgraded from version 1.89_01 to 1.994.
+
+This fixes, among other things, incorrect results when computing binomial
+coefficients [perl #77640].
+
+It also prevents C<sqrt($int)> from crashing under C<use bigrat>.
+[perl #73534].
+
+=item *
+
+L<Math::BigInt::FastCalc> has been upgraded from version 0.19 to 0.28.
+
+=item *
+
+L<Math::BigRat> has been upgraded from version 0.24 to 0.26_02.
+
+=item *
+
+L<Memoize> has been upgraded from version 1.01_03 to 1.02.
+
+=item *
+
+L<MIME::Base64> has been upgraded from 3.08 to 3.13.
+
+Includes new functions to calculate the length of encoded and decoded
+base64 strings.
+
+Now provides encode_base64url() and decode_base64url() functions to process
+the base64 scheme for "URL applications".
+
+=item *
+
+L<Module::Build> has been upgraded from version 0.3603 to 0.3800.
+
+A notable change is the deprecation of several modules.
+L<Module::Build::Version> has been deprecated and L<Module::Build> now
+relies on the L<version> pragma directly. L<Module::Build::ModuleInfo> has
+been deprecated in favor of a standalone copy called L<Module::Metadata>.
+L<Module::Build::YAML> has been deprecated in favor of L<CPAN::Meta::YAML>.
+
+L<Module::Build> now also generates F<META.json> and F<MYMETA.json> files
+in accordance with version 2 of the CPAN distribution metadata specification,
+L<CPAN::Meta::Spec>. The older format F<META.yml> and F<MYMETA.yml> files are
+still generated.
+
+=item *
+
+L<Module::CoreList> has been upgraded from version 2.29 to 2.47.
+
+Besides listing the updated core modules of this release, it also stops listing
+the C<Filespec> module. That module never existed in core. The scripts
+generating L<Module::CoreList> confused it with L<VMS::Filespec>, which actually
+is a core module as of Perl 5.8.7.
+
+=item *
+
+L<Module::Load> has been upgraded from version 0.16 to 0.18.
+
+=item *
+
+L<Module::Load::Conditional> has been upgraded from version 0.34 to 0.44.
+
+=item *
+
+The L<mro> pragma has been upgraded from version 1.02 to 1.07.
+
+=item *
+
+L<NDBM_File> has been upgraded from version 1.08 to 1.12.
+
+This fixes a memory leak when DBM filters are used.
+
+=item *
+
+L<Net::Ping> has been upgraded from version 2.36 to 2.38.
+
+=item *
+
+L<NEXT> has been upgraded from version 0.64 to 0.65.
+
+=item *
+
+L<Object::Accessor> has been upgraded from version 0.36 to 0.38.
+
+=item *
+
+L<ODBM_File> has been upgraded from version 1.07 to 1.10.
+
+This fixes a memory leak when DBM filters are used.
+
+=item *
+
+L<Opcode> has been upgraded from version 1.15 to 1.18.
+
+=item *
+
+The L<overload> pragma has been upgraded from 1.10 to 1.13.
+
+C<overload::Method> can now handle subroutines that are themselves blessed
+into overloaded classes [perl #71998].
+
+The documentation has greatly improved. See L</Documentation> below.
+
+=item *
+
+L<Params::Check> has been upgraded from version 0.26 to 0.28.
+
+=item *
+
+The L<parent> pragma has been upgraded from version 0.223 to 0.225.
+
+=item *
+
+L<Parse::CPAN::Meta> has been upgraded from version 1.40 to 1.4401.
+
+The latest Parse::CPAN::Meta can now read YAML and JSON files using
+L<CPAN::Meta::YAML> and L<JSON::PP>, which are now part of the Perl core.
+
+=item *
+
+L<PerlIO::encoding> has been upgraded from version 0.12 to 0.14.
+
+=item *
+
+L<PerlIO::scalar> has been upgraded from 0.07 to 0.11.
+
+A read() after a seek() beyond the end of the string no longer thinks it
+has data to read [perl #78716].
+
+=item *
+
+L<PerlIO::via> has been upgraded from version 0.09 to 0.11.
+
+=item *
+
+L<Pod::Html> has been upgraded from version 1.09 to 1.11.
+
+=item *
+
+L<Pod::LaTeX> has been upgraded from version 0.58 to 0.59.
+
+=item *
+
+L<Pod::Perldoc> has been upgraded from version 3.15_02 to 3.15_03.
+
+=item *
+
+L<Pod::Simple> has been upgraded from version 3.13 to 3.16.
+
+=item *
+
+L<POSIX> has been upgraded from 1.19 to 1.24.
+
+It now includes constants for POSIX signal constants.
+
+=item *
+
+The L<re> pragma has been upgraded from version 0.11 to 0.18.
+
+The C<use re '/flags'> subpragma is new.
+
+The regmust() function used to crash when called on a regular expression
+belonging to a pluggable engine. Now it croaks instead.
+
+regmust() no longer leaks memory.
+
+=item *
+
+L<Safe> has been upgraded from version 2.25 to 2.29.
+
+Coderefs returned by reval() and rdo() are now wrapped via
+wrap_code_refs() (5.12.1).
+
+This fixes a possible infinite loop when looking for coderefs.
+
+It adds several C<version::vxs::*> routines to the default share.
+
+=item *
+
+L<SDBM_File> has been upgraded from version 1.06 to 1.09.
+
+=item *
+
+L<SelfLoader> has been upgraded from 1.17 to 1.18.
+
+It now works in taint mode [perl #72062].
+
+=item *
+
+The L<sigtrap> pragma has been upgraded from version 1.04 to 1.05.
+
+It no longer tries to modify read-only arguments when generating a
+backtrace [perl #72340].
+
+=item *
+
+L<Socket> has been upgraded from version 1.87 to 1.94.
+
+See L</Improved IPv6 support> above.
+
+=item *
+
+L<Storable> has been upgraded from version 2.22 to 2.27.
+
+Includes performance improvement for overloaded classes.
+
+This adds support for serialising code references that contain UTF-8 strings
+correctly. The L<Storable> minor version
+number changed as a result, meaning that
+L<Storable> users who set C<$Storable::accept_future_minor> to a C<FALSE> value
+will see errors (see L<Storable/FORWARD COMPATIBILITY> for more details).
+
+Freezing no longer gets confused if the Perl stack gets reallocated
+during freezing [perl #80074].
+
+=item *
+
+L<Sys::Hostname> has been upgraded from version 1.11 to 1.16.
+
+=item *
+
+L<Term::ANSIColor> has been upgraded from version 2.02 to 3.00.
+
+=item *
+
+L<Term::UI> has been upgraded from version 0.20 to 0.26.
+
+=item *
+
+L<Test::Harness> has been upgraded from version 3.17 to 3.23.
+
+=item *
+
+L<Test::Simple> has been upgraded from version 0.94 to 0.98.
+
+Among many other things, subtests without a C<plan> or C<no_plan> now have an
+implicit done_testing() added to them.
+
+=item *
+
+L<Thread::Semaphore> has been upgraded from version 2.09 to 2.12.
+
+It provides two new methods that give more control over the decrementing of
+semaphores: C<down_nb> and C<down_force>.
+
+=item *
+
+L<Thread::Queue> has been upgraded from version 2.11 to 2.12.
+
+=item *
+
+The L<threads> pragma has been upgraded from version 1.75 to 1.83.
+
+=item *
+
+The L<threads::shared> pragma has been upgraded from version 1.32 to 1.37.
+
+=item *
+
+L<Tie::Hash> has been upgraded from version 1.03 to 1.04.
+
+Calling C<< Tie::Hash->TIEHASH() >> used to loop forever. Now it C<croak>s.
+
+=item *
+
+L<Tie::Hash::NamedCapture> has been upgraded from version 0.06 to 0.08.
+
+=item *
+
+L<Tie::RefHash> has been upgraded from version 1.38 to 1.39.
+
+=item *
+
+L<Time::HiRes> has been upgraded from version 1.9719 to 1.9721_01.
+
+=item *
+
+L<Time::Local> has been upgraded from version 1.1901_01 to 1.2000.
+
+=item *
+
+L<Time::Piece> has been upgraded from version 1.15_01 to 1.20_01.
+
+=item *
+
+L<Unicode::Collate> has been upgraded from version 0.52_01 to 0.73.
+
+L<Unicode::Collate> has been updated to use Unicode 6.0.0.
+
+L<Unicode::Collate::Locale> now supports a plethora of new locales: I<ar, be,
+bg, de__phonebook, hu, hy, kk, mk, nso, om, tn, vi, hr, ig, ja, ko, ru, sq,
+se, sr, to, uk, zh, zh__big5han, zh__gb2312han, zh__pinyin>, and I<zh__stroke>.
+
+The following modules have been added:
+
+L<Unicode::Collate::CJK::Big5> for C<zh__big5han> which makes
+tailoring of CJK Unified Ideographs in the order of CLDR's big5han ordering.
+
+L<Unicode::Collate::CJK::GB2312> for C<zh__gb2312han> which makes
+tailoring of CJK Unified Ideographs in the order of CLDR's gb2312han ordering.
+
+L<Unicode::Collate::CJK::JISX0208> which makes tailoring of 6355 kanji
+(CJK Unified Ideographs) in the JIS X 0208 order.
+
+L<Unicode::Collate::CJK::Korean> which makes tailoring of CJK Unified Ideographs
+in the order of CLDR's Korean ordering.
+
+L<Unicode::Collate::CJK::Pinyin> for C<zh__pinyin> which makes
+tailoring of CJK Unified Ideographs in the order of CLDR's pinyin ordering.
+
+L<Unicode::Collate::CJK::Stroke> for C<zh__stroke> which makes
+tailoring of CJK Unified Ideographs in the order of CLDR's stroke ordering.
+
+This also sees the switch from using the pure-Perl version of this
+module to the XS version.
+
+=item *
+
+L<Unicode::Normalize> has been upgraded from version 1.03 to 1.10.
+
+=item *
+
+L<Unicode::UCD> has been upgraded from version 0.27 to 0.32.
+
+A new function, Unicode::UCD::num(), has been added. This function
+returns the numeric value of the string passed it or C<undef> if the string
+in its entirety has no "safe" numeric value. (For more detail, and for the
+definition of "safe", see L<Unicode::UCD/num>.)
+
+This upgrade also includes several bug fixes:
+
+=over 4
+
+=item charinfo()
+
+=over 4
+
+=item *
+
+It is now updated to Unicode Version 6.0.0 with I<Corrigendum #8>,
+excepting that, just as with Perl 5.14, the code point at U+1F514 has no name.
+
+=item *
+
+Hangul syllable code points have the correct names, and their
+decompositions are always output without requiring L<Lingua::KO::Hangul::Util>
+to be installed.
+
+=item *
+
+CJK (Chinese-Japanese-Korean) code points U+2A700 to U+2B734
+and U+2B740 to U+2B81D are now properly handled.
+
+=item *
+
+Numeric values are now output for those CJK code points that have them.
+
+=item *
+
+Names output for code points with multiple aliases are now the
+corrected ones.
+
+=back
+
+=item charscript()
+
+This now correctly returns "Unknown" instead of C<undef> for the script
+of a code point that hasn't been assigned another one.
+
+=item charblock()
+
+This now correctly returns "No_Block" instead of C<undef> for the block
+of a code point that hasn't been assigned to another one.
+
+=back
+
+=item *
+
+The L<version> pragma has been upgraded from 0.82 to 0.88.
+
+Because of a bug, now fixed, the is_strict() and is_lax() functions did not
+work when exported (5.12.1).
+
+=item *
+
+The L<warnings> pragma has been upgraded from version 1.09 to 1.12.
+
+Calling C<use warnings> without arguments is now significantly more efficient.
+
+=item *
+
+The L<warnings::register> pragma has been upgraded from version 1.01 to 1.02.
+
+It is now possible to register warning categories other than the names of
+packages using L<warnings::register>. See L<perllexwarn(1)> for more information.
+
+=item *
+
+L<XSLoader> has been upgraded from version 0.10 to 0.13.
+
+=item *
+
+L<VMS::DCLsym> has been upgraded from version 1.03 to 1.05.
+
+Two bugs have been fixed [perl #84086]:
+
+The symbol table name was lost when tying a hash, due to a thinko in
+C<TIEHASH>. The result was that all tied hashes interacted with the
+local symbol table.
+
+Unless a symbol table name had been explicitly specified in the call
+to the constructor, querying the special key C<:LOCAL> failed to
+identify objects connected to the local symbol table.
+
+=item *
+
+The L<Win32> module has been upgraded from version 0.39 to 0.44.
+
+This release has several new functions: Win32::GetSystemMetrics(),
+Win32::GetProductInfo(), Win32::GetOSDisplayName().
+
+The names returned by Win32::GetOSName() and Win32::GetOSDisplayName()
+have been corrected.
+
+=item *
+
+L<XS::Typemap> has been upgraded from version 0.03 to 0.05.
+
+=back
+
+=head2 Removed Modules and Pragmata
+
+As promised in Perl 5.12.0's release notes, the following modules have
+been removed from the core distribution, and if needed should be installed
+from CPAN instead.
+
+=over
+
+=item *
+
+L<Class::ISA> has been removed from the Perl core. Prior version was 0.36.
+
+=item *
+
+L<Pod::Plainer> has been removed from the Perl core. Prior version was 1.02.
+
+=item *
+
+L<Switch> has been removed from the Perl core. Prior version was 2.16.
+
+=back
+
+The removal of L<Shell> has been deferred until after 5.14, as the
+implementation of L<Shell> shipped with 5.12.0 did not correctly issue the
+warning that it was to be removed from core.
+
+=head1 Documentation
+
+=head2 New Documentation
+
+=head3 L<perlgpl>
+
+L<perlgpl> has been updated to contain GPL version 1, as is included in the
+F<README> distributed with Perl (5.12.1).
+
+=head3 Perl 5.12.x delta files
+
+The perldelta files for Perl 5.12.1 to 5.12.3 have been added from the
+maintenance branch: L<perl5121delta>, L<perl5122delta>, L<perl5123delta>.
+
+=head3 L<perlpodstyle>
+
+New style guide for POD documentation,
+split mostly from the NOTES section of the L<pod2man(1)> manpage.
+
+=head3 L<perlsource>, L<perlinterp>, L<perlhacktut>, and L<perlhacktips>
+
+See L</perlhack and perlrepository revamp>, below.
+
+=head2 Changes to Existing Documentation
+
+=head3 L<perlmodlib> is now complete
+
+The L<perlmodlib> manpage that came with Perl 5.12.0 was missing several
+modules due to a bug in the script that generates the list. This has been
+fixed [perl #74332] (5.12.1).
+
+=head3 Replace incorrect tr/// table in L<perlebcdic>
+
+L<perlebcdic> contains a helpful table to use in C<tr///> to convert
+between EBCDIC and Latin1/ASCII. The table was the inverse of the one
+it describes, though the code that used the table worked correctly for
+the specific example given.
+
+The table has been corrected and the sample code changed to correspond.
+
+The table has also been changed to hex from octal, and the recipes in the
+pod have been altered to print out leading zeros to make all values
+the same length.
+
+=head3 Tricks for user-defined casing
+
+L<perlunicode> now contains an explanation of how to override, mangle
+and otherwise tweak the way Perl handles upper-, lower- and other-case
+conversions on Unicode data, and how to provide scoped changes to alter
+one's own code's behaviour without stomping on anybody else's.
+
+=head3 INSTALL explicitly states that Perl requires a C89 compiler
+
+This was already true, but it's now Officially Stated For The Record
+(5.12.2).
+
+=head3 Explanation of C<\xI<HH>> and C<\oI<OOO>> escapes
+
+L<perlop> has been updated with more detailed explanation of these two
+character escapes.
+
+=head3 B<-0I<NNN>> switch
+
+In L<perlrun>, the behaviour of the B<-0NNN> switch for B<-0400> or higher
+has been clarified (5.12.2).
+
+=head3 Maintenance policy
+
+L<perlpolicy> now contains the policy on what patches are acceptable for
+maintenance branches (5.12.1).
+
+=head3 Deprecation policy
+
+L<perlpolicy> now contains the policy on compatibility and deprecation
+along with definitions of terms like "deprecation" (5.12.2).
+
+=head3 New descriptions in L<perldiag>
+
+The following existing diagnostics are now documented:
+
+=over 4
+
+=item *
+
+L<Ambiguous use of %c resolved as operator %c|perldiag/"Ambiguous use of %c resolved as operator %c">
+
+=item *
+
+L<Ambiguous use of %c{%s} resolved to %c%s|perldiag/"Ambiguous use of %c{%s} resolved to %c%s">
+
+=item *
+
+L<Ambiguous use of %c{%s[...]} resolved to %c%s[...]|perldiag/"Ambiguous use of %c{%s[...]} resolved to %c%s[...]">
+
+=item *
+
+L<Ambiguous use of %c{%s{...}} resolved to %c%s{...}|perldiag/"Ambiguous use of %c{%s{...}} resolved to %c%s{...}">
+
+=item *
+
+L<Ambiguous use of -%s resolved as -&%s()|perldiag/"Ambiguous use of -%s resolved as -&%s()">
+
+=item *
+
+L<Invalid strict version format (%s)|perldiag/"Invalid strict version format (%s)">
+
+=item *
+
+L<Invalid version format (%s)|perldiag/"Invalid version format (%s)">
+
+=item *
+
+L<Invalid version object|perldiag/"Invalid version object">
+
+=back
+
+=head3 L<perlbook>
+
+L<perlbook> has been expanded to cover many more popular books.
+
+=head3 C<SvTRUE> macro
+
+The documentation for the C<SvTRUE> macro in
+L<perlapi> was simply wrong in stating that
+get-magic is not processed. It has been corrected.
+
+=head3 op manipulation functions
+
+Several API functions that process optrees have been newly documented.
+
+=head3 L<perlvar> revamp
+
+L<perlvar> reorders the variables and groups them by topic. Each variable
+introduced after Perl 5.000 notes the first version in which it is
+available. L<perlvar> also has a new section for deprecated variables to
+note when they were removed.
+
+=head3 Array and hash slices in scalar context
+
+These are now documented in L<perldata>.
+
+=head3 C<use locale> and formats
+
+L<perlform> and L<perllocale> have been corrected to state that
+C<use locale> affects formats.
+
+=head3 L<overload>
+
+L<overload>'s documentation has practically undergone a rewrite. It
+is now much more straightforward and clear.
+
+=head3 perlhack and perlrepository revamp
+
+The L<perlhack> document is now much shorter, and focuses on the Perl 5
+development process and submitting patches to Perl. The technical content
+has been moved to several new documents, L<perlsource>, L<perlinterp>,
+L<perlhacktut>, and L<perlhacktips>. This technical content has
+been only lightly edited.
+
+The perlrepository document has been renamed to L<perlgit>. This new
+document is just a how-to on using git with the Perl source code.
+Any other content that used to be in perlrepository has been moved
+to L<perlhack>.
+
+=head3 Time::Piece examples
+
+Examples in L<perlfaq4> have been updated to show the use of
+L<Time::Piece>.
+
+=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
+
+=item Closure prototype called
+
+This error occurs when a subroutine reference passed to an attribute
+handler is called, if the subroutine is a closure [perl #68560].
+
+=item Insecure user-defined property %s
+
+Perl detected tainted data when trying to compile a regular
+expression that contains a call to a user-defined character property
+function, meaning C<\p{IsFoo}> or C<\p{InFoo}>.
+See L<perlunicode/User-Defined Character Properties> and L<perlsec>.
+
+=item panic: gp_free failed to free glob pointer - something is repeatedly re-creating entries
+
+This new error is triggered if a destructor called on an object in a
+typeglob that is being freed creates a new typeglob entry containing an
+object with a destructor that creates a new entry containing an object etc.
+
+=item Parsing code internal error (%s)
+
+This new fatal error is produced when parsing
+code supplied by an extension violates the
+parser's API in a detectable way.
+
+=item refcnt: fd %d%s
+
+This new error only occurs if a internal consistency check fails when a
+pipe is about to be closed.
+
+=item Regexp modifier "/%c" may not appear twice
+
+The regular expression pattern has one of the
+mutually exclusive modifiers repeated.
+
+=item Regexp modifiers "/%c" and "/%c" are mutually exclusive
+
+The regular expression pattern has more than one of the mutually
+exclusive modifiers.
+
+=item Using !~ with %s doesn't make sense
+
+This error occurs when C<!~> is used with C<s///r> or C<y///r>.
+
+=back
+
+=head3 New Warnings
+
+=over
+
+=item "\b{" is deprecated; use "\b\{" instead
+
+=item "\B{" is deprecated; use "\B\{" instead
+
+Use of an unescaped "{" immediately following a C<\b> or C<\B> is now
+deprecated in order to reserve its use for Perl itself in a future release.
+
+=item Operation "%s" returns its argument for ...
+
+Performing an operation requiring Unicode semantics (such as case-folding)
+on a Unicode surrogate or a non-Unicode character now triggers this
+warning.
+
+=item Use of qw(...) as parentheses is deprecated
+
+See L</"Use of qw(...) as parentheses">, above, for details.
+
+=back
+
+=head2 Changes to Existing Diagnostics
+
+=over 4
+
+=item *
+
+The "Variable $foo is not imported" warning that precedes a
+C<strict 'vars'> error has now been assigned the "misc" category, so that
+C<no warnings> will suppress it [perl #73712].
+
+=item *
+
+warn() and die() now produce "Wide character" warnings when fed a
+character outside the byte range if C<STDERR> is a byte-sized handle.
+
+=item *
+
+The "Layer does not match this perl" error message has been replaced with
+these more helpful messages [perl #73754]:
+
+=over 4
+
+=item *
+
+PerlIO layer function table size (%d) does not match size expected by this
+perl (%d)
+
+=item *
+
+PerlIO layer instance size (%d) does not match size expected by this perl
+(%d)
+
+=back
+
+=item *
+
+The "Found = in conditional" warning that is emitted when a constant is
+assigned to a variable in a condition is now withheld if the constant is
+actually a subroutine or one generated by C<use constant>, since the value
+of the constant may not be known at the time the program is written
+[perl #77762].
+
+=item *
+
+Previously, if none of the gethostbyaddr(), gethostbyname() and
+gethostent() functions were implemented on a given platform, they would
+all die with the message "Unsupported socket function 'gethostent' called",
+with analogous messages for getnet*() and getserv*(). This has been
+corrected.
+
+=item *
+
+The warning message about unrecognized regular expression escapes passed
+through has been changed to include any literal "{" following the
+two-character escape. For example, "\q{" is now emitted instead of "\q".
+
+=back
+
+=head1 Utility Changes
+
+=head3 L<perlbug(1)>
+
+=over 4
+
+=item *
+
+L<perlbug> now looks in the EMAIL environment variable for a return address
+if the REPLY-TO and REPLYTO variables are empty.
+
+=item *
+
+L<perlbug> did not previously generate a "From:" header, potentially
+resulting in dropped mail; it now includes that header.
+
+=item *
+
+The user's address is now used as the Return-Path.
+
+Many systems these days don't have a valid Internet domain name, and
+perlbug@perl.org does not accept email with a return-path that does
+not resolve. So the user's address is now passed to sendmail so it's
+less likely to get stuck in a mail queue somewhere [perl #82996].
+
+=item *
+
+L<perlbug> now always gives the reporter a chance to change the email
+address it guesses for them (5.12.2).
+
+=item *
+
+L<perlbug> should no longer warn about uninitialized values when using the B<-d>
+and B<-v> options (5.12.2).
+
+=back
+
+=head3 L<perl5db.pl>
+
+=over
+
+=item *
+
+The remote terminal works after forking and spawns new sessions, one
+per forked process.
+
+=back
+
+=head3 L<ptargrep>
+
+=over 4
+
+=item *
+
+L<ptargrep> is a new utility to apply pattern matching to the contents of
+files in a tar archive. It comes with C<Archive::Tar>.
+
+=back
+
+=head1 Configuration and Compilation
+
+See also L</"Naming fixes in Policy_sh.SH may invalidate Policy.sh">,
+above.
+
+=over 4
+
+=item *
+
+CCINCDIR and CCLIBDIR for the mingw64 cross-compiler are now correctly
+under F<$(CCHOME)\mingw\include> and F<\lib> rather than immediately below
+F<$(CCHOME)>.
+
+This means the "incpath", "libpth", "ldflags", "lddlflags" and
+"ldflags_nolargefiles" values in F<Config.pm> and F<Config_heavy.pl> are now
+set correctly.
+
+=item *
+
+C<make test.valgrind> has been adjusted to account for F<cpan/dist/ext>
+separation.
+
+=item *
+
+On compilers that support it, B<-Wwrite-strings> is now added to cflags by
+default.
+
+=item *
+
+The L<Encode> module can now (once again) be included in a static Perl
+build. The special-case handling for this situation got broken in Perl
+5.11.0, and has now been repaired.
+
+=item *
+
+The previous default size of a PerlIO buffer (4096 bytes) has been increased
+to the larger of 8192 bytes and your local BUFSIZ. Benchmarks show that doubling
+this decade-old default increases read and write performance by around
+25% to 50% when using the default layers of perlio on top of unix. To choose
+a non-default size, such as to get back the old value or to obtain an even
+larger value, configure with:
+
+ ./Configure -Accflags=-DPERLIOBUF_DEFAULT_BUFSIZ=N
+
+where N is the desired size in bytes; it should probably be a multiple of
+your page size.
+
+=item *
+
+An "incompatible operand types" error in ternary expressions when building
+with C<clang> has been fixed (5.12.2).
+
+=item *
+
+Perl now skips setuid L<File::Copy> tests on partitions it detects mounted
+as C<nosuid> (5.12.2).
+
+=back
+
+=head1 Platform Support
+
+=head2 New Platforms
+
+=over 4
+
+=item AIX
+
+Perl now builds on AIX 4.2 (5.12.1).
+
+=back
+
+=head2 Discontinued Platforms
+
+=over 4
+
+=item Apollo DomainOS
+
+The last vestiges of support for this platform have been excised from
+the Perl distribution. It was officially discontinued in version 5.12.0.
+It had not worked for years before that.
+
+=item MacOS Classic
+
+The last vestiges of support for this platform have been excised from the
+Perl distribution. It was officially discontinued in an earlier version.
+
+=back
+
+=head2 Platform-Specific Notes
+
+=head3 AIX
+
+=over
+
+=item *
+
+F<README.aix> has been updated with information about the XL C/C++ V11 compiler
+suite (5.12.2).
+
+=back
+
+=head3 ARM
+
+=over
+
+=item *
+
+The C<d_u32align> configuration probe on ARM has been fixed (5.12.2).
+
+=back
+
+=head3 Cygwin
+
+=over 4
+
+=item *
+
+L<MakeMaker> has been updated to build manpages on cygwin.
+
+=item *
+
+Improved rebase behaviour
+
+If a DLL is updated on cygwin the old imagebase address is reused.
+This solves most rebase errors, especially when updating on core DLL's.
+See L<http://www.tishler.net/jason/software/rebase/rebase-2.4.2.README>
+for more information.
+
+=item *
+
+Support for the standard cygwin dll prefix (needed for FFIs)
+
+=item *
+
+Updated build hints file
+
+=back
+
+=head3 FreeBSD 7
+
+=over
+
+=item *
+
+FreeBSD 7 no longer contains F</usr/bin/objformat>. At build time,
+Perl now skips the F<objformat> check for versions 7 and higher and
+assumes ELF (5.12.1).
+
+=back
+
+=head3 HP-UX
+
+=over
+
+=item *
+
+Perl now allows B<-Duse64bitint> without promoting to C<use64bitall> on HP-UX
+(5.12.1).
+
+=back
+
+=head3 IRIX
+
+=over
+
+=item *
+
+Conversion of strings to floating-point numbers is now more accurate on
+IRIX systems [perl #32380].
+
+=back
+
+=head3 Mac OS X
+
+=over
+
+=item *
+
+Early versions of Mac OS X (Darwin) had buggy implementations of the
+setregid(), setreuid(), setrgid(,) and setruid() functions, so Perl
+would pretend they did not exist.
+
+These functions are now recognised on Mac OS 10.5 (Leopard; Darwin 9) and
+higher, as they have been fixed [perl #72990].
+
+=back
+
+=head3 MirBSD
+
+=over
+
+=item *
+
+Previously if you built Perl with a shared F<libperl.so> on MirBSD (the
+default config), it would work up to the installation; however, once
+installed, it would be unable to find F<libperl>. Path handling is now
+treated as in the other BSD dialects.
+
+=back
+
+=head3 NetBSD
+
+=over
+
+=item *
+
+The NetBSD hints file has been changed to make the system malloc the
+default.
+
+=back
+
+=head3 OpenBSD
+
+=over
+
+=item *
+
+OpenBSD E<gt> 3.7 has a new malloc implementation which is I<mmap>-based,
+and as such can release memory back to the OS; however, Perl's use of
+this malloc causes a substantial slowdown, so we now default to using
+Perl's malloc instead [perl #75742].
+
+=back
+
+=head3 OpenVOS
+
+=over
+
+=item *
+
+Perl now builds again with OpenVOS (formerly known as Stratus VOS)
+[perl #78132] (5.12.3).
+
+=back
+
+=head3 Solaris
+
+=over
+
+=item *
+
+DTrace is now supported on Solaris. There used to be build failures, but
+these have been fixed [perl #73630] (5.12.3).
+
+=back
+
+=head3 VMS
+
+=over
+
+=item *
+
+Extension building on older (pre 7.3-2) VMS systems was broken because
+configure.com hit the DCL symbol length limit of 1K. We now work within
+this limit when assembling the list of extensions in the core build (5.12.1).
+
+=item *
+
+We fixed configuring and building Perl with B<-Uuseperlio> (5.12.1).
+
+=item *
+
+C<PerlIOUnix_open> now honours the default permissions on VMS.
+
+When C<perlio> became the default and C<unix> became the default bottom layer,
+the most common path for creating files from Perl became C<PerlIOUnix_open>,
+which has always explicitly used C<0666> as the permission mask. This prevents
+inheriting permissions from RMS defaults and ACLs, so to avoid that problem,
+we now pass C<0777> to open(). In theVMS CRTL, C<0777> has a special
+meaning over and above intersecting with the current umask; specifically, it
+allows Unix syscalls to preserve native default permissions (5.12.3).
+
+=item *
+
+The shortening of symbols longer than 31 characters in the core C sources
+and in extensions is now by default done by the C compiler rather than by
+xsubpp (which could only do so for generated symbols in XS code). You can
+reenable xsubpp's symbol shortening by configuring with -Uuseshortenedsymbols,
+but you'll have some work to do to get the core sources to compile.
+
+=item *
+
+Record-oriented files (record format variable or variable with fixed control)
+opened for write by the C<perlio> layer will now be line-buffered to prevent the
+introduction of spurious line breaks whenever the perlio buffer fills up.
+
+=item *
+
+F<git_version.h> is now installed on VMS. This was an oversight in v5.12.0 which
+caused some extensions to fail to build (5.12.2).
+
+=item *
+
+Several memory leaks in L<stat()|perlfunc/"stat FILEHANDLE"> have been fixed (5.12.2).
+
+=item *
+
+A memory leak in Perl_rename() due to a double allocation has been
+fixed (5.12.2).
+
+=item *
+
+A memory leak in vms_fid_to_name() (used by realpath() and
+realname()> has been fixed (5.12.2).
+
+=back
+
+=head3 Windows
+
+See also L</"fork() emulation will not wait for signalled children"> and
+L</"Perl source code is read in text mode on Windows">, above.
+
+=over 4
+
+=item *
+
+Fixed build process for SDK2003SP1 compilers.
+
+=item *
+
+Compilation with Visual Studio 2010 is now supported.
+
+=item *
+
+When using old 32-bit compilers, the define C<_USE_32BIT_TIME_T> is now
+set in C<$Config{ccflags}>. This improves portability when compiling
+XS extensions using new compilers, but for a Perl compiled with old 32-bit
+compilers.
+
+=item *
+
+C<$Config{gccversion}> is now set correctly when Perl is built using the
+mingw64 compiler from L<http://mingw64.org> [perl #73754].
+
+=item *
+
+When building Perl with the mingw64 x64 cross-compiler C<incpath>,
+C<libpth>, C<ldflags>, C<lddlflags> and C<ldflags_nolargefiles> values
+in F<Config.pm> and F<Config_heavy.pl> were not previously being set
+correctly because, with that compiler, the include and lib directories
+are not immediately below C<$(CCHOME)> (5.12.2).
+
+=item *
+
+The build process proceeds more smoothly with mingw and dmake when
+F<C:\MSYS\bin> is in the PATH, due to a C<Cwd> fix.
+
+=item *
+
+Support for building with Visual C++ 2010 is now underway, but is not yet
+complete. See F<README.win32> or L<perlwin32> for more details.
+
+=item *
+
+The option to use an externally-supplied crypt(), or to build with no
+crypt() at all, has been removed. Perl supplies its own crypt()
+implementation for Windows, and the political situation that required
+this part of the distribution to sometimes be omitted is long gone.
+
+=back
+
+=head1 Internal Changes
+
+=head2 New APIs
+
+=head3 CLONE_PARAMS structure added to ease correct thread creation
+
+Modules that create threads should now create C<CLONE_PARAMS> structures
+by calling the new function Perl_clone_params_new(), and free them with
+Perl_clone_params_del(). This will ensure compatibility with any future
+changes to the internals of the C<CLONE_PARAMS> structure layout, and that
+it is correctly allocated and initialised.
+
+=head3 New parsing functions
+
+Several functions have been added for parsing Perl statements and
+expressions. These functions are meant to be used by XS code invoked
+during Perl parsing, in a recursive-descent manner, to allow modules to
+augment the standard Perl syntax.
+
+=over
+
+=item *
+
+L<parse_stmtseq()|perlapi/parse_stmtseq>
+parses a sequence of statements, up to closing brace or EOF.
+
+=item *
+
+L<parse_fullstmt()|perlapi/parse_fullstmt>
+parses a complete Perl statement, including optional label.
+
+=item *
+
+L<parse_barestmt()|perlapi/parse_barestmt>
+parses a statement without a label.
+
+=item *
+
+L<parse_block()|perlapi/parse_block>
+parses a code block.
+
+=item *
+
+L<parse_label()|perlapi/parse_label>
+parses a statement label, separate from statements.
+
+=item *
+
+L<C<parse_fullexpr()>|perlapi/parse_fullexpr>,
+L<C<parse_listexpr()>|perlapi/parse_listexpr>,
+L<C<parse_termexpr()>|perlapi/parse_termexpr>, and
+L<C<parse_arithexpr()>|perlapi/parse_arithexpr>
+parse expressions at various precedence levels.
+
+=back
+
+=head3 Hints hash API
+
+A new C API for introspecting the hinthash C<%^H> at runtime has been
+added. See C<cop_hints_2hv>, C<cop_hints_fetchpvn>, C<cop_hints_fetchpvs>,
+C<cop_hints_fetchsv>, and C<hv_copy_hints_hv> in L<perlapi> for details.
+
+A new, experimental API has been added for accessing the internal
+structure that Perl uses for C<%^H>. See the functions beginning with
+C<cophh_> in L<perlapi>.
+
+=head3 C interface to caller()
+
+The C<caller_cx> function has been added as an XSUB-writer's equivalent of
+caller(). See L<perlapi> for details.
+
+=head3 Custom per-subroutine check hooks
+
+XS code in an extension module can now annotate a subroutine (whether
+implemented in XS or in Perl) so that nominated XS code will be called
+at compile time (specifically as part of op checking) to change the op
+tree of that subroutine. The compile-time check function (supplied by
+the extension module) can implement argument processing that can't be
+expressed as a prototype, generate customised compile-time warnings,
+perform constant folding for a pure function, inline a subroutine
+consisting of sufficiently simple ops, replace the whole call with a
+custom op, and so on. This was previously all possible by hooking the
+C<entersub> op checker, but the new mechanism makes it easy to tie the
+hook to a specific subroutine. See L<perlapi/cv_set_call_checker>.
+
+To help in writing custom check hooks, several subtasks within standard
+C<entersub> op checking have been separated out and exposed in the API.
+
+=head3 Improved support for custom OPs
+
+Custom ops can now be registered with the new C<custom_op_register> C
+function and the C<XOP> structure. This will make it easier to add new
+properties of custom ops in the future. Two new properties have been added
+already, C<xop_class> and C<xop_peep>.
+
+C<xop_class> is one of the OA_*OP constants. It allows L<B> and other
+introspection mechanisms to work with custom ops
+that aren't BASEOPs. C<xop_peep> is a pointer to
+a function that will be called for ops of this
+type from C<Perl_rpeep>.
+
+See L<perlguts/Custom Operators> and L<perlapi/Custom Operators> for more
+detail.
+
+The old C<PL_custom_op_names>/C<PL_custom_op_descs> interface is still
+supported but discouraged.
+
+=head3 Scope hooks
+
+It is now possible for XS code to hook into Perl's lexical scope
+mechanism at compile time, using the new C<Perl_blockhook_register>
+function. See L<perlguts/"Compile-time scope hooks">.
+
+=head3 The recursive part of the peephole optimizer is now hookable
+
+In addition to C<PL_peepp>, for hooking into the toplevel peephole optimizer, a
+C<PL_rpeepp> is now available to hook into the optimizer recursing into
+side-chains of the optree.
+
+=head3 New non-magical variants of existing functions
+
+The following functions/macros have been added to the API. The C<*_nomg>
+macros are equivalent to their non-C<_nomg> variants, except that they ignore
+get-magic. Those ending in C<_flags> allow one to specify whether
+get-magic is processed.
+
+ sv_2bool_flags
+ SvTRUE_nomg
+ sv_2nv_flags
+ SvNV_nomg
+ sv_cmp_flags
+ sv_cmp_locale_flags
+ sv_eq_flags
+ sv_collxfrm_flags
+
+In some of these cases, the non-C<_flags> functions have
+been replaced with wrappers around the new functions.
+
+=head3 pv/pvs/sv versions of existing functions
+
+Many functions ending with pvn now have equivalent C<pv/pvs/sv> versions.
+
+=head3 List op-building functions
+
+List op-building functions have been added to the
+API. See L<op_append_elem|perlapi/op_append_elem>,
+L<op_append_list|perlapi/op_append_list>, and
+L<op_prepend_elem|perlapi/op_prepend_elem> in L<perlapi>.
+
+=head3 C<LINKLIST>
+
+The L<LINKLIST|perlapi/LINKLIST> macro, part of op building that
+constructs the execution-order op chain, has been added to the API.
+
+=head3 Localisation functions
+
+The C<save_freeop>, C<save_op>, C<save_pushi32ptr> and C<save_pushptrptr>
+functions have been added to the API.
+
+=head3 Stash names
+
+A stash can now have a list of effective names in addition to its usual
+name. The first effective name can be accessed via the C<HvENAME> macro,
+which is now the recommended name to use in MRO linearisations (C<HvNAME>
+being a fallback if there is no C<HvENAME>).
+
+These names are added and deleted via C<hv_ename_add> and
+C<hv_ename_delete>. These two functions are I<not> part of the API.
+
+=head3 New functions for finding and removing magic
+
+The L<C<mg_findext()>|perlapi/mg_findext> and
+L<C<sv_unmagicext()>|perlapi/sv_unmagicext>
+functions have been added to the API.
+They allow extension authors to find and remove magic attached to
+scalars based on both the magic type and the magic virtual table, similar to how
+sv_magicext() attaches magic of a certain type and with a given virtual table
+to a scalar. This eliminates the need for extensions to walk the list of
+C<MAGIC> pointers of an C<SV> to find the magic that belongs to them.
+
+=head3 C<find_rundefsv>
+
+This function returns the SV representing C<$_>, whether it's lexical
+or dynamic.
+
+=head3 C<Perl_croak_no_modify>
+
+Perl_croak_no_modify() is short-hand for
+C<Perl_croak("%s", PL_no_modify)>.
+
+=head3 C<PERL_STATIC_INLINE> define
+
+The C<PERL_STATIC_INLINE> define has been added to provide the best-guess
+incantation to use for static inline functions, if the C compiler supports
+C99-style static inline. If it doesn't, it'll give a plain C<static>.
+
+C<HAS_STATIC_INLINE> can be used to check if the compiler actually supports
+inline functions.
+
+=head3 New C<pv_escape> option for hexadecimal escapes
+
+A new option, C<PERL_PV_ESCAPE_NONASCII>, has been added to C<pv_escape> to
+dump all characters above ASCII in hexadecimal. Before, one could get all
+characters as hexadecimal or the Latin1 non-ASCII as octal.
+
+=head3 C<lex_start>
+
+C<lex_start> has been added to the API, but is considered experimental.
+
+=head3 op_scope() and op_lvalue()
+
+The op_scope() and op_lvalue() functions have been added to the API,
+but are considered experimental.
+
+=head2 C API Changes
+
+=head3 C<PERL_POLLUTE> has been removed
+
+The option to define C<PERL_POLLUTE> to expose older 5.005 symbols for
+backwards compatibility has been removed. Its use was always discouraged,
+and MakeMaker contains a more specific escape hatch:
+
+ perl Makefile.PL POLLUTE=1
+
+This can be used for modules that have not been upgraded to 5.6 naming
+conventions (and really should be completely obsolete by now).
+
+=head3 Check API compatibility when loading XS modules
+
+When Perl's API changes in incompatible ways (which usually happens between
+major releases), XS modules compiled for previous versions of Perl will no
+longer work. They need to be recompiled against the new Perl.
+
+The C<XS_APIVERSION_BOOTCHECK> macro has been added to ensure that modules
+are recompiled and to prevent users from accidentally loading modules
+compiled for old perls into newer perls. That macro, which is called when
+loading every newly compiled extension, compares the API version of the
+running perl with the version a module has been compiled for and raises an
+exception if they don't match.
+
+=head3 Perl_fetch_cop_label
+
+The first argument of the C API function C<Perl_fetch_cop_label> has changed
+from C<struct refcounted_he *> to C<COP *>, to insulate the user from
+implementation details.
+
+This API function was marked as "may change", and likely isn't in use outside
+the core. (Neither an unpacked CPAN nor Google's codesearch finds any other
+references to it.)
+
+=head3 GvCV() and GvGP() are no longer lvalues
+
+The new GvCV_set() and GvGP_set() macros are now provided to replace
+assignment to those two macros.
+
+This allows a future commit to eliminate some backref magic between GV
+and CVs, which will require complete control over assignment to the
+C<gp_cv> slot.
+
+=head3 CvGV() is no longer an lvalue
+
+Under some circumstances, the CvGV() field of a CV is now
+reference-counted. To ensure consistent behaviour, direct assignment to
+it, for example C<CvGV(cv) = gv> is now a compile-time error. A new macro,
+C<CvGV_set(cv,gv)> has been introduced to run this operation
+safely. Note that modification of this field is not part of the public
+API, regardless of this new macro (and despite its being listed in this section).
+
+=head3 CvSTASH() is no longer an lvalue
+
+The CvSTASH() macro can now only be used as an rvalue. CvSTASH_set()
+has been added to replace assignment to CvSTASH(). This is to ensure
+that backreferences are handled properly. These macros are not part of the
+API.
+
+=head3 Calling conventions for C<newFOROP> and C<newWHILEOP>
+
+The way the parser handles labels has been cleaned up and refactored. As a
+result, the newFOROP() constructor function no longer takes a parameter
+stating what label is to go in the state op.
+
+The newWHILEOP() and newFOROP() functions no longer accept a line
+number as a parameter.
+
+=head3 Flags passed to C<uvuni_to_utf8_flags> and C<utf8n_to_uvuni>
+
+Some of the flags parameters to uvuni_to_utf8_flags() and
+utf8n_to_uvuni() have changed. This is a result of Perl's now allowing
+internal storage and manipulation of code points that are problematic
+in some situations. Hence, the default actions for these functions has
+been complemented to allow these code points. The new flags are
+documented in L<perlapi>. Code that requires the problematic code
+points to be rejected needs to change to use the new flags. Some flag
+names are retained for backward source compatibility, though they do
+nothing, as they are now the default. However the flags
+C<UNICODE_ALLOW_FDD0>, C<UNICODE_ALLOW_FFFF>, C<UNICODE_ILLEGAL>, and
+C<UNICODE_IS_ILLEGAL> have been removed, as they stem from a
+fundamentally broken model of how the Unicode non-character code points
+should be handled, which is now described in
+L<perlunicode/Non-character code points>. See also the Unicode section
+under L</Selected Bug Fixes>.
+
+=head2 Deprecated C APIs
+
+=over
+
+=item C<Perl_ptr_table_clear>
+
+C<Perl_ptr_table_clear> is no longer part of Perl's public API. Calling it
+now generates a deprecation warning, and it will be removed in a future
+release.
+
+=item C<sv_compile_2op>
+
+The sv_compile_2op() API function is now deprecated. Searches suggest
+that nothing on CPAN is using it, so this should have zero impact.
+
+It attempted to provide an API to compile code down to an optree, but failed
+to bind correctly to lexicals in the enclosing scope. It's not possible to
+fix this problem within the constraints of its parameters and return value.
+
+=item C<find_rundefsvoffset>
+
+The C<find_rundefsvoffset> function has been deprecated. It appeared that
+its design was insufficient for reliably getting the lexical C<$_> at
+run-time.
+
+Use the new C<find_rundefsv> function or the C<UNDERBAR> macro
+instead. They directly return the right SV
+representing C<$_>, whether it's
+lexical or dynamic.
+
+=item C<CALL_FPTR> and C<CPERLscope>
+
+Those are left from an old implementation of C<MULTIPLICITY> using C++ objects,
+which was removed in Perl 5.8. Nowadays these macros do exactly nothing, so
+they shouldn't be used anymore.
+
+For compatibility, they are still defined for external C<XS> code. Only
+extensions defining C<PERL_CORE> must be updated now.
+
+=back
+
+=head2 Other Internal Changes
+
+=head3 Stack unwinding
+
+The protocol for unwinding the C stack at the last stage of a C<die>
+has changed how it identifies the target stack frame. This now uses
+a separate variable C<PL_restartjmpenv>, where previously it relied on
+the C<blk_eval.cur_top_env> pointer in the C<eval> context frame that
+has nominally just been discarded. This change means that code running
+during various stages of Perl-level unwinding no longer needs to take
+care to avoid destroying the ghost frame.
+
+=head3 Scope stack entries
+
+The format of entries on the scope stack has been changed, resulting in a
+reduction of memory usage of about 10%. In particular, the memory used by
+the scope stack to record each active lexical variable has been halved.
+
+=head3 Memory allocation for pointer tables
+
+Memory allocation for pointer tables has been changed. Previously
+C<Perl_ptr_table_store> allocated memory from the same arena system as
+C<SV> bodies and C<HE>s, with freed memory remaining bound to those arenas
+until interpreter exit. Now it allocates memory from arenas private to the
+specific pointer table, and that memory is returned to the system when
+C<Perl_ptr_table_free> is called. Additionally, allocation and release are
+both less CPU intensive.
+
+=head3 C<UNDERBAR>
+
+The C<UNDERBAR> macro now calls C<find_rundefsv>. C<dUNDERBAR> is now a
+noop but should still be used to ensure past and future compatibility.
+
+=head3 String comparison routines renamed
+
+The C<ibcmp_*> functions have been renamed and are now called C<foldEQ>,
+C<foldEQ_locale>, and C<foldEQ_utf8>. The old names are still available as
+macros.
+
+=head3 C<chop> and C<chomp> implementations merged
+
+The opcode bodies for C<chop> and C<chomp> and for C<schop> and C<schomp>
+have been merged. The implementation functions Perl_do_chop() and
+Perl_do_chomp(), never part of the public API, have been merged and
+moved to a static function in F<pp.c>. This shrinks the Perl binary
+slightly, and should not affect any code outside the core (unless it is
+relying on the order of side-effects when C<chomp> is passed a I<list> of
+values).
+
+=head1 Selected Bug Fixes
+
+=head2 I/O
+
+=over 4
+
+=item *
+
+Perl no longer produces this warning:
+
+ $ perl -we 'open(my $f, ">", \my $x); binmode($f, "scalar")'
+ Use of uninitialized value in binmode at -e line 1.
+
+=item *
+
+Opening a glob reference via C<< open($fh, ">", \*glob) >> no longer
+causes the glob to be corrupted when the filehandle is printed to. This would
+cause Perl to crash whenever the glob's contents were accessed
+[perl #77492].
+
+=item *
+
+PerlIO no longer crashes when called recursively, such as from a signal
+handler. Now it just leaks memory [perl #75556].
+
+=item *
+
+Most I/O functions were not warning for unopened handles unless the
+"closed" and "unopened" warnings categories were both enabled. Now only
+C<use warnings 'unopened'> is necessary to trigger these warnings, as
+had always been the intention.
+
+=item *
+
+There have been several fixes to PerlIO layers:
+
+When C<binmode(FH, ":crlf")> pushes the C<:crlf> layer on top of the stack,
+it no longer enables crlf layers lower in the stack so as to avoid
+unexpected results [perl #38456].
+
+Opening a file in C<:raw> mode now does what it advertises to do (first
+open the file, then C<binmode> it), instead of simply leaving off the top
+layer [perl #80764].
+
+The three layers C<:pop>, C<:utf8>, and C<:bytes> didn't allow stacking when
+opening a file. For example
+this:
+
+ open(FH, ">:pop:perlio", "some.file") or die $!;
+
+would throw an "Invalid argument" error. This has been fixed in this
+release [perl #82484].
+
+=back
+
+=head2 Regular Expression Bug Fixes
+
+=over
+
+=item *
+
+The regular expression engine no longer loops when matching
+C<"\N{LATIN SMALL LIGATURE FF}" =~ /f+/i> and similar expressions
+[perl #72998] (5.12.1).
+
+=item *
+
+The trie runtime code should no longer allocate massive amounts of memory,
+fixing #74484.
+
+=item *
+
+Syntax errors in C<< (?{...}) >> blocks no longer cause panic messages
+[perl #2353].
+
+=item *
+
+A pattern like C<(?:(o){2})?> no longer causes a "panic" error
+[perl #39233].
+
+=item *
+
+A fatal error in regular expressions containing C<(.*?)> when processing
+UTF-8 data has been fixed [perl #75680] (5.12.2).
+
+=item *
+
+An erroneous regular expression engine optimisation that caused regex verbs like
+C<*COMMIT> sometimes to be ignored has been removed.
+
+=item *
+
+The regular expression bracketed character class C<[\8\9]> was effectively the
+same as C<[89\000]>, incorrectly matching a NULL character. It also gave
+incorrect warnings that the C<8> and C<9> were ignored. Now C<[\8\9]> is the
+same as C<[89]> and gives legitimate warnings that C<\8> and C<\9> are
+unrecognized escape sequences, passed-through.
+
+=item *
+
+A regular expression match in the right-hand side of a global substitution
+(C<s///g>) that is in the same scope will no longer cause match variables
+to have the wrong values on subsequent iterations. This can happen when an
+array or hash subscript is interpolated in the right-hand side, as in
+C<s|(.)|@a{ print($1), /./ }|g> [perl #19078].
+
+=item *
+
+Several cases in which characters in the Latin-1 non-ASCII range (0x80 to
+0xFF) used not to match themselves, or used to match both a character class
+and its complement, have been fixed. For instance, U+00E2 could match both
+C<\w> and C<\W> [perl #78464] [perl #18281] [perl #60156].
+
+=item *
+
+Matching a Unicode character against an alternation containing characters
+that happened to match continuation bytes in the former's UTF8
+representation (like C<qq{\x{30ab}} =~ /\xab|\xa9/>) would cause erroneous
+warnings [perl #70998].
+
+=item *
+
+The trie optimisation was not taking empty groups into account, preventing
+"foo" from matching C</\A(?:(?:)foo|bar|zot)\z/> [perl #78356].
+
+=item *
+
+A pattern containing a C<+> inside a lookahead would sometimes cause an
+incorrect match failure in a global match (for example, C</(?=(\S+))/g>)
+[perl #68564].
+
+=item *
+
+A regular expression optimisation would sometimes cause a match with a
+C<{n,m}> quantifier to fail when it should have matched [perl #79152].
+
+=item *
+
+Case-insensitive matching in regular expressions compiled under
+C<use locale> now works much more sanely when the pattern or target
+string is internally encoded in UTF8. Previously, under these
+conditions the localeness was completely lost. Now, code points
+above 255 are treated as Unicode, but code points between 0 and 255
+are treated using the current locale rules, regardless of whether
+the pattern or the string is encoded in UTF8. The few case-insensitive
+matches that cross the 255/256 boundary are not allowed. For
+example, 0xFF does not caselessly match the character at 0x178,
+LATIN CAPITAL LETTER Y WITH DIAERESIS, because 0xFF may not be LATIN
+SMALL LETTER Y in the current locale, and Perl has no way of knowing
+if that character even exists in the locale, much less what code
+point it is.
+
+=item *
+
+The C<(?|...)> regular expression construct no longer crashes if the final
+branch has more sets of capturing parentheses than any other branch. This
+was fixed in Perl 5.10.1 for the case of a single branch, but that fix did
+not take multiple branches into account [perl #84746].
+
+=item *
+
+A bug has been fixed in the implementation of C<{...}> quantifiers in
+regular expressions that prevented the code block in
+C</((\w+)(?{ print $2 })){2}/> from seeing the C<$2> sometimes
+[perl #84294].
+
+=back
+
+=head2 Syntax/Parsing Bugs
+
+=over
+
+=item *
+
+C<when (scalar) {...}> no longer crashes, but produces a syntax error
+[perl #74114] (5.12.1).
+
+=item *
+
+A label right before a string eval (C<foo: eval $string>) no longer causes
+the label to be associated also with the first statement inside the eval
+[perl #74290] (5.12.1).
+
+=item *
+
+The C<no 5.13.2> form of C<no> no longer tries to turn on features or
+pragmata (like L<strict>) [perl #70075] (5.12.2).
+
+=item *
+
+C<BEGIN {require 5.12.0}> now behaves as documented, rather than behaving
+identically to C<use 5.12.0>. Previously, C<require> in a C<BEGIN> block
+was erroneously executing the C<use feature ':5.12.0'> and
+C<use strict> behaviour, which only C<use> was documented to
+provide [perl #69050].
+
+=item *
+
+A regression introduced in Perl 5.12.0, making
+C<< my $x = 3; $x = length(undef) >> result in C<$x> set to C<3> has been
+fixed. C<$x> will now be C<undef> [perl #85508] (5.12.2).
+
+=item *
+
+When strict "refs" mode is off, C<%{...}> in rvalue context returns
+C<undef> if its argument is undefined. An optimisation introduced in Perl
+5.12.0 to make C<keys %{...}> faster when used as a boolean did not take
+this into account, causing C<keys %{+undef}> (and C<keys %$foo> when
+C<$foo> is undefined) to be an error, which it should be so in strict
+mode only [perl #81750].
+
+=item *
+
+Constant-folding used to cause
+
+ $text =~ ( 1 ? /phoo/ : /bear/)
+
+to turn into
+
+ $text =~ /phoo/
+
+at compile time. Now it correctly matches against C<$_> [perl #20444].
+
+=item *
+
+Parsing Perl code (either with string C<eval> or by loading modules) from
+within a C<UNITCHECK> block no longer causes the interpreter to crash
+[perl #70614].
+
+=item *
+
+String C<eval>s no longer fail after 2 billion scopes have been
+compiled [perl #83364].
+
+=item *
+
+The parser no longer hangs when encountering certain Unicode characters,
+such as U+387 [perl #74022].
+
+=item *
+
+Defining a constant with the same name as one of Perl's special blocks
+(like C<INIT>) stopped working in 5.12.0, but has now been fixed
+[perl #78634].
+
+=item *
+
+A reference to a literal value used as a hash key (C<$hash{\"foo"}>) used
+to be stringified, even if the hash was tied [perl #79178].
+
+=item *
+
+A closure containing an C<if> statement followed by a constant or variable
+is no longer treated as a constant [perl #63540].
+
+=item *
+
+C<state> can now be used with attributes. It
+used to mean the same thing as
+C<my> if any attributes were present [perl #68658].
+
+=item *
+
+Expressions like C<< @$a > 3 >> no longer cause C<$a> to be mentioned in
+the "Use of uninitialized value in numeric gt" warning when C<$a> is
+undefined (since it is not part of the C<< > >> expression, but the operand
+of the C<@>) [perl #72090].
+
+=item *
+
+Accessing an element of a package array with a hard-coded number (as
+opposed to an arbitrary expression) would crash if the array did not exist.
+Usually the array would be autovivified during compilation, but typeglob
+manipulation could remove it, as in these two cases which used to crash:
+
+ *d = *a; print $d[0];
+ undef *d; print $d[0];
+
+=item *
+
+The B<-C> command-line option, when used on the shebang line, can now be
+followed by other options [perl #72434].
+
+=item *
+
+The C<B> module was returning C<B::OP>s instead of C<B::LOGOP>s for
+C<entertry> [perl #80622]. This was due to a bug in the Perl core,
+not in C<B> itself.
+
+=back
+
+=head2 Stashes, Globs and Method Lookup
+
+Perl 5.10.0 introduced a new internal mechanism for caching MROs (method
+resolution orders, or lists of parent classes; aka "isa" caches) to make
+method lookup faster (so C<@ISA> arrays would not have to be searched
+repeatedly). Unfortunately, this brought with it quite a few bugs. Almost
+all of these have been fixed now, along with a few MRO-related bugs that
+existed before 5.10.0:
+
+=over
+
+=item *
+
+The following used to have erratic effects on method resolution, because
+the "isa" caches were not reset or otherwise ended up listing the wrong
+classes. These have been fixed.
+
+=over
+
+=item Aliasing packages by assigning to globs [perl #77358]
+
+=item Deleting packages by deleting their containing stash elements
+
+=item Undefining the glob containing a package (C<undef *Foo::>)
+
+=item Undefining an ISA glob (C<undef *Foo::ISA>)
+
+=item Deleting an ISA stash element (C<delete $Foo::{ISA}>)
+
+=item Sharing @ISA arrays between classes (via C<*Foo::ISA = \@Bar::ISA> or
+C<*Foo::ISA = *Bar::ISA>) [perl #77238]
+
+=back
+
+C<undef *Foo::ISA> would even stop a new C<@Foo::ISA> array from updating
+caches.
+
+=item *
+
+Typeglob assignments would crash if the glob's stash no longer existed, so
+long as the glob assigned to were named C<ISA> or the glob on either side of
+the assignment contained a subroutine.
+
+=item *
+
+C<PL_isarev>, which is accessible to Perl via C<mro::get_isarev> is now
+updated properly when packages are deleted or removed from the C<@ISA> of
+other classes. This allows many packages to be created and deleted without
+causing a memory leak [perl #75176].
+
+=back
+
+In addition, various other bugs related to typeglobs and stashes have been
+fixed:
+
+=over
+
+=item *
+
+Some work has been done on the internal pointers that link between symbol
+tables (stashes), typeglobs, and subroutines. This has the effect that
+various edge cases related to deleting stashes or stash entries (for example,
+<%FOO:: = ()>), and complex typeglob or code-reference aliasing, will no
+longer crash the interpreter.
+
+=item *
+
+Assigning a reference to a glob copy now assigns to a glob slot instead of
+overwriting the glob with a scalar [perl #1804] [perl #77508].
+
+=item *
+
+A bug when replacing the glob of a loop variable within the loop has been fixed
+[perl #21469]. This
+means the following code will no longer crash:
+
+ for $x (...) {
+ *x = *y;
+ }
+
+=item *
+
+Assigning a glob to a PVLV used to convert it to a plain string. Now it
+works correctly, and a PVLV can hold a glob. This would happen when a
+nonexistent hash or array element was passed to a subroutine:
+
+ sub { $_[0] = *foo }->($hash{key});
+ # $_[0] would have been the string "*main::foo"
+
+It also happened when a glob was assigned to, or returned from, an element
+of a tied array or hash [perl #36051].
+
+=item *
+
+When trying to report C<Use of uninitialized value $Foo::BAR>, crashes could
+occur if the glob holding the global variable in question had been detached
+from its original stash by, for example, C<delete $::{"Foo::"}>. This has
+been fixed by disabling the reporting of variable names in those
+cases.
+
+=item *
+
+During the restoration of a localised typeglob on scope exit, any
+destructors called as a result would be able to see the typeglob in an
+inconsistent state, containing freed entries, which could result in a
+crash. This would affect code like this:
+
+ local *@;
+ eval { die bless [] }; # puts an object in $@
+ sub DESTROY {
+ local $@; # boom
+ }
+
+Now the glob entries are cleared before any destructors are called. This
+also means that destructors can vivify entries in the glob. So Perl tries
+again and, if the entries are re-created too many times, dies with a
+"panic: gp_free ..." error message.
+
+=item *
+
+If a typeglob is freed while a subroutine attached to it is still
+referenced elsewhere, the subroutine is renamed to C<__ANON__> in the same
+package, unless the package has been undefined, in which case the C<__ANON__>
+package is used. This could cause packages to be sometimes autovivified,
+such as if the package had been deleted. Now this no longer occurs.
+The C<__ANON__> package is also now used when the original package is
+no longer attached to the symbol table. This avoids memory leaks in some
+cases [perl #87664].
+
+=item *
+
+Subroutines and package variables inside a package whose name ends with
+C<::> can now be accessed with a fully qualified name.
+
+=back
+
+=head2 Unicode
+
+=over
+
+=item *
+
+What has become known as "the Unicode Bug" is almost completely resolved in
+this release. Under C<use feature 'unicode_strings'> (which is
+automatically selected by C<use 5.012> and above), the internal
+storage format of a string no longer affects the external semantics.
+[perl #58182].
+
+There are two known exceptions:
+
+=over
+
+=item 1
+
+The now-deprecated, user-defined case-changing
+functions require utf8-encoded strings to operate. The CPAN module
+L<Unicode::Casing> has been written to replace this feature without its
+drawbacks, and the feature is scheduled to be removed in 5.16.
+
+=item 2
+
+quotemeta() (and its in-line equivalent C<\Q>) can also give different
+results depending on whether a string is encoded in UTF-8. See
+L<perlunicode/The "Unicode Bug">.
+
+=back
+
+=item *
+
+Handling of Unicode non-character code points has changed.
+Previously they were mostly considered illegal, except that in some
+place only one of the 66 of them was known. The Unicode Standard
+considers them all legal, but forbids their "open interchange".
+This is part of the change to allow internal use of any code
+point (see L</Core Enhancements>). Together, these changes resolve
+[perl #38722], [perl #51918], [perl #51936], and [perl #63446].
+
+=item *
+
+Case-insensitive C<"/i"> regular expression matching of Unicode
+characters that match multiple characters now works much more as
+intended. For example
+
+ "\N{LATIN SMALL LIGATURE FFI}" =~ /ffi/ui
+
+and
+
+ "ffi" =~ /\N{LATIN SMALL LIGATURE FFI}/ui
+
+are both true. Previously, there were many bugs with this feature.
+What hasn't been fixed are the places where the pattern contains the
+multiple characters, but the characters are split up by other things,
+such as in
+
+ "\N{LATIN SMALL LIGATURE FFI}" =~ /(f)(f)i/ui
+
+or
+
+ "\N{LATIN SMALL LIGATURE FFI}" =~ /ffi*/ui
+
+or
+
+ "\N{LATIN SMALL LIGATURE FFI}" =~ /[a-f][f-m][g-z]/ui
+
+None of these match.
+
+Also, this matching doesn't fully conform to the current Unicode
+Standard, which asks that the matching be made upon the NFD
+(Normalization Form Decomposed) of the text. However, as of this
+writing (April 2010), the Unicode Standard is currently in flux about
+what they will recommend doing with regard in such scenarios. It may be
+that they will throw out the whole concept of multi-character matches.
+[perl #71736].
+
+=item *
+
+Naming a deprecated character in C<\N{I<NAME>}> no longer leaks memory.
+
+=item *
+
+We fixed a bug that could cause C<\N{I<NAME>}> constructs followed by
+a single C<"."> to be parsed incorrectly [perl #74978] (5.12.1).
+
+=item *
+
+C<chop> now correctly handles characters above C<"\x{7fffffff}">
+[perl #73246].
+
+=item *
+
+Passing to C<index> an offset beyond the end of the string when the string
+is encoded internally in UTF8 no longer causes panics [perl #75898].
+
+=item *
+
+warn() and die() now respect utf8-encoded scalars [perl #45549].
+
+=item *
+
+Sometimes the UTF8 length cache would not be reset on a value
+returned by substr, causing C<length(substr($uni_string, ...))> to give
+wrong answers. With C<${^UTF8CACHE}> set to -1, it would also produce
+a "panic" error message [perl #77692].
+
+=back
+
+=head2 Ties, Overloading and Other Magic
+
+=over
+
+=item *
+
+Overloading now works properly in conjunction with tied
+variables. What formerly happened was that most ops checked their
+arguments for overloading I<before> checking for magic, so for example
+an overloaded object returned by a tied array access would usually be
+treated as not overloaded [RT #57012].
+
+=item *
+
+Various instances of magic (like tie methods) being called on tied variables
+too many or too few times have been fixed:
+
+=over
+
+=item *
+
+C<< $tied->() >> did not always call FETCH [perl #8438].
+
+=item *
+
+Filetest operators and C<y///> and C<tr///> were calling FETCH too
+many times.
+
+=item *
+
+The C<=> operator used to ignore magic on its right-hand side if the
+scalar happened to hold a typeglob (if a typeglob was the last thing
+returned from or assigned to a tied scalar) [perl #77498].
+
+=item *
+
+Dereference operators used to ignore magic if the argument was a
+reference already (such as from a previous FETCH) [perl #72144].
+
+=item *
+
+C<splice> now calls set-magic (so changes made
+by C<splice @ISA> are respected by method calls) [perl #78400].
+
+=item *
+
+In-memory files created by C<< open($fh, ">", \$buffer) >> were not calling
+FETCH/STORE at all [perl #43789] (5.12.2).
+
+=item *
+
+utf8::is_utf8() now respects get-magic (like C<$1>) (5.12.1).
+
+=back
+
+=item *
+
+Non-commutative binary operators used to swap their operands if the same
+tied scalar was used for both operands and returned a different value for
+each FETCH. For instance, if C<$t> returned 2 the first time and 3 the
+second, then C<$t/$t> would evaluate to 1.5. This has been fixed
+[perl #87708].
+
+=item *
+
+String C<eval> now detects taintedness of overloaded or tied
+arguments [perl #75716].
+
+=item *
+
+String C<eval> and regular expression matches against objects with string
+overloading no longer cause memory corruption or crashes [perl #77084].
+
+=item *
+
+L<readline|perlfunc/"readline EXPR"> now honors C<< <> >> overloading on tied
+arguments.
+
+=item *
+
+C<< <expr> >> always respects overloading now if the expression is
+overloaded.
+
+Because "S<< <> as >> glob" was parsed differently from
+"S<< <> as >> filehandle" from 5.6 onwards, something like C<< <$foo[0]> >> did
+not handle overloading, even if C<$foo[0]> was an overloaded object. This
+was contrary to the documentation for L<overload>, and meant that C<< <> >>
+could not be used as a general overloaded iterator operator.
+
+=item *
+
+The fallback behaviour of overloading on binary operators was asymmetric
+[perl #71286].
+
+=item *
+
+Magic applied to variables in the main package no longer affects other packages.
+See L</Magic variables outside the main package> above [perl #76138].
+
+=item *
+
+Sometimes magic (ties, taintedness, etc.) attached to variables could cause
+an object to last longer than it should, or cause a crash if a tied
+variable were freed from within a tie method. These have been fixed
+[perl #81230].
+
+=item *
+
+DESTROY methods of objects implementing ties are no longer able to crash by
+accessing the tied variable through a weak reference [perl #86328].
+
+=item *
+
+Fixed a regression of kill() when a match variable is used for the
+process ID to kill [perl #75812].
+
+=item *
+
+C<$AUTOLOAD> used to remain tainted forever if it ever became tainted. Now
+it is correctly untainted if an autoloaded method is called and the method
+name was not tainted.
+
+=item *
+
+C<sprintf> now dies when passed a tainted scalar for the format. It did
+already die for arbitrary expressions, but not for simple scalars
+[perl #82250].
+
+=item *
+
+C<lc>, C<uc>, C<lcfirst>, and C<ucfirst> no longer return untainted strings
+when the argument is tainted. This has been broken since perl 5.8.9
+[perl #87336].
+
+=back
+
+=head2 The Debugger
+
+=over
+
+=item *
+
+The Perl debugger now also works in taint mode [perl #76872].
+
+=item *
+
+Subroutine redefinition works once more in the debugger [perl #48332].
+
+=item *
+
+When B<-d> is used on the shebang (C<#!>) line, the debugger now has access
+to the lines of the main program. In the past, this sometimes worked and
+sometimes did not, depending on the order in which things happened to be
+arranged in memory [perl #71806].
+
+=item *
+
+A possible memory leak when using L<caller()|perlfunc/"caller EXPR"> to set
+C<@DB::args> has been fixed (5.12.2).
+
+=item *
+
+Perl no longer stomps on C<$DB::single>, C<$DB::trace>, and C<$DB::signal>
+if these variables already have values when C<$^P> is assigned to [perl #72422].
+
+=item *
+
+C<#line> directives in string evals were not properly updating the arrays
+of lines of code (C<< @{"_< ..."} >>) that the debugger (or any debugging or
+profiling module) uses. In threaded builds, they were not being updated at
+all. In non-threaded builds, the line number was ignored, so any change to
+the existing line number would cause the lines to be misnumbered
+[perl #79442].
+
+=back
+
+=head2 Threads
+
+=over
+
+=item *
+
+Perl no longer accidentally clones lexicals in scope within active stack
+frames in the parent when creating a child thread [perl #73086].
+
+=item *
+
+Several memory leaks in cloning and freeing threaded Perl interpreters have been
+fixed [perl #77352].
+
+=item *
+
+Creating a new thread when directory handles were open used to cause a
+crash, because the handles were not cloned, but simply passed to the new
+thread, resulting in a double free.
+
+Now directory handles are cloned properly on Windows
+and on systems that have a C<fchdir> function. On other
+systems, new threads simply do not inherit directory
+handles from their parent threads [perl #75154].
+
+=item *
+
+The typeglob C<*,>, which holds the scalar variable C<$,> (output field
+separator), had the wrong reference count in child threads.
+
+=item *
+
+[perl #78494] When pipes are shared between threads, the C<close> function
+(and any implicit close, such as on thread exit) no longer blocks.
+
+=item *
+
+Perl now does a timely cleanup of SVs that are cloned into a new
+thread but then discovered to be orphaned (that is, their owners
+are I<not> cloned). This eliminates several "scalars leaked"
+warnings when joining threads.
+
+=back
+
+=head2 Scoping and Subroutines
+
+=over
+
+=item *
+
+Lvalue subroutines are again able to return copy-on-write scalars. This
+had been broken since version 5.10.0 [perl #75656] (5.12.3).
+
+=item *
+
+C<require> no longer causes C<caller> to return the wrong file name for
+the scope that called C<require> and other scopes higher up that had the
+same file name [perl #68712].
+
+=item *
+
+C<sort> with a C<($$)>-prototyped comparison routine used to cause the value
+of C<@_> to leak out of the sort. Taking a reference to C<@_> within the
+sorting routine could cause a crash [perl #72334].
+
+=item *
+
+Match variables (like C<$1>) no longer persist between calls to a sort
+subroutine [perl #76026].
+
+=item *
+
+Iterating with C<foreach> over an array returned by an lvalue sub now works
+[perl #23790].
+
+=item *
+
+C<$@> is now localised during calls to C<binmode> to prevent action at a
+distance [perl #78844].
+
+=item *
+
+Calling a closure prototype (what is passed to an attribute handler for a
+closure) now results in a "Closure prototype called" error message instead
+of a crash [perl #68560].
+
+=item *
+
+Mentioning a read-only lexical variable from the enclosing scope in a
+string C<eval> no longer causes the variable to become writable
+[perl #19135].
+
+=back
+
+=head2 Signals
+
+=over
+
+=item *
+
+Within signal handlers, C<$!> is now implicitly localized.
+
+=item *
+
+CHLD signals are no longer unblocked after a signal handler is called if
+they were blocked before by C<POSIX::sigprocmask> [perl #82040].
+
+=item *
+
+A signal handler called within a signal handler could cause leaks or
+double-frees. Now fixed [perl #76248].
+
+=back
+
+=head2 Miscellaneous Memory Leaks
+
+=over
+
+=item *
+
+Several memory leaks when loading XS modules were fixed (5.12.2).
+
+=item *
+
+L<substr()|perlfunc/"substr EXPR,OFFSET,LENGTH,REPLACEMENT">,
+L<pos()|perlfunc/"index STR,SUBSTR,POSITION">, L<keys()|perlfunc/"keys HASH">,
+and L<vec()|perlfunc/"vec EXPR,OFFSET,BITS"> could, when used in combination
+with lvalues, result in leaking the scalar value they operate on, and cause its
+destruction to happen too late. This has now been fixed.
+
+=item *
+
+The postincrement and postdecrement operators, C<++> and C<-->, used to cause
+leaks when used on references. This has now been fixed.
+
+=item *
+
+Nested C<map> and C<grep> blocks no longer leak memory when processing
+large lists [perl #48004].
+
+=item *
+
+C<use I<VERSION>> and C<no I<VERSION>> no longer leak memory [perl #78436]
+[perl #69050].
+
+=item *
+
+C<.=> followed by C<< <> >> or C<readline> would leak memory if C<$/>
+contained characters beyond the octet range and the scalar assigned to
+happened to be encoded as UTF8 internally [perl #72246].
+
+=item *
+
+C<eval 'BEGIN{die}'> no longer leaks memory on non-threaded builds.
+
+=back
+
+=head2 Memory Corruption and Crashes
+
+=over
+
+=item *
+
+glob() no longer crashes when C<%File::Glob::> is empty and
+C<CORE::GLOBAL::glob> isn't present [perl #75464] (5.12.2).
+
+=item *
+
+readline() has been fixed when interrupted by signals so it no longer
+returns the "same thing" as before or random memory.
+
+=item *
+
+When assigning a list with duplicated keys to a hash, the assignment used to
+return garbage and/or freed values:
+
+ @a = %h = (list with some duplicate keys);
+
+This has now been fixed [perl #31865].
+
+=item *
+
+The mechanism for freeing objects in globs used to leave dangling
+pointers to freed SVs, meaning Perl users could see corrupted state
+during destruction.
+
+Perl now frees only the affected slots of the GV, rather than freeing
+the GV itself. This makes sure that there are no dangling refs or
+corrupted state during destruction.
+
+=item *
+
+The interpreter no longer crashes when freeing deeply-nested arrays of
+arrays. Hashes have not been fixed yet [perl #44225].
+
+=item *
+
+Concatenating long strings under C<use encoding> no longer causes Perl to
+crash [perl #78674].
+
+=item *
+
+Calling C<< ->import >> on a class lacking an import method could corrupt
+the stack, resulting in strange behaviour. For instance,
+
+ push @a, "foo", $b = bar->import;
+
+would assign "foo" to C<$b> [perl #63790].
+
+=item *
+
+The C<recv> function could crash when called with the MSG_TRUNC flag
+[perl #75082].
+
+=item *
+
+C<formline> no longer crashes when passed a tainted format picture. It also
+taints C<$^A> now if its arguments are tainted [perl #79138].
+
+=item *
+
+A bug in how we process filetest operations could cause a segfault.
+Filetests don't always expect an op on the stack, so we now use
+TOPs only if we're sure that we're not C<stat>ing the C<_> filehandle.
+This is indicated by C<OPf_KIDS> (as checked in ck_ftst) [perl #74542]
+(5.12.1).
+
+=item *
+
+unpack() now handles scalar context correctly for C<%32H> and C<%32u>,
+fixing a potential crash. split() would crash because the third item
+on the stack wasn't the regular expression it expected. C<unpack("%2H",
+...)> would return both the unpacked result and the checksum on the stack,
+as would C<unpack("%2u", ...)> [perl #73814] (5.12.2).
+
+=back
+
+=head2 Fixes to Various Perl Operators
+
+=over
+
+=item *
+
+The C<&>, C<|>, and C<^> bitwise operators no longer coerce read-only arguments
+[perl #20661].
+
+=item *
+
+Stringifying a scalar containing "-0.0" no longer has the effect of turning
+false into true [perl #45133].
+
+=item *
+
+Some numeric operators were converting integers to floating point,
+resulting in loss of precision on 64-bit platforms [perl #77456].
+
+=item *
+
+sprintf() was ignoring locales when called with constant arguments
+[perl #78632].
+
+=item *
+
+Combining the vector (C<%v>) flag and dynamic precision would
+cause C<sprintf> to confuse the order of its arguments, making it
+treat the string as the precision and vice-versa [perl #83194].
+
+=back
+
+=head2 Bugs Relating to the C API
+
+=over
+
+=item *
+
+The C-level C<lex_stuff_pvn> function would sometimes cause a spurious
+syntax error on the last line of the file if it lacked a final semicolon
+[perl #74006] (5.12.1).
+
+=item *
+
+The C<eval_sv> and C<eval_pv> C functions now set C<$@> correctly when
+there is a syntax error and no C<G_KEEPERR> flag, and never set it if the
+C<G_KEEPERR> flag is present [perl #3719].
+
+=item *
+
+The XS multicall API no longer causes subroutines to lose reference counts
+if called via the multicall interface from within those very subroutines.
+This affects modules like L<List::Util>. Calling one of its functions with an
+active subroutine as the first argument could cause a crash [perl #78070].
+
+=item *
+
+The C<SvPVbyte> function available to XS modules now calls magic before
+downgrading the SV, to avoid warnings about wide characters [perl #72398].
+
+=item *
+
+The ref types in the typemap for XS bindings now support magical variables
+[perl #72684].
+
+=item *
+
+C<sv_catsv_flags> no longer calls C<mg_get> on its second argument (the
+source string) if the flags passed to it do not include SV_GMAGIC. So it
+now matches the documentation.
+
+=item *
+
+C<my_strftime> no longer leaks memory. This fixes a memory leak in
+C<POSIX::strftime> [perl #73520].
+
+=item *
+
+F<XSUB.h> now correctly redefines fgets under PERL_IMPLICIT_SYS [perl #55049]
+(5.12.1).
+
+=item *
+
+XS code using fputc() or fputs() on Windows could cause an error
+due to their arguments being swapped [perl #72704] (5.12.1).
+
+=item *
+
+A possible segfault in the C<T_PTROBJ> default typemap has been fixed
+(5.12.2).
+
+=item *
+
+A bug that could cause "Unknown error" messages when
+C<call_sv(code, G_EVAL)> is called from an XS destructor has been fixed
+(5.12.2).
+
+=back
+
+=head1 Known Problems
+
+This is a list of significant unresolved issues which are regressions
+from earlier versions of Perl or which affect widely-used CPAN modules.
+
+=over 4
+
+=item *
+
+C<List::Util::first> misbehaves in the presence of a lexical C<$_>
+(typically introduced by C<my $_> or implicitly by C<given>). The variable
+that gets set for each iteration is the package variable C<$_>, not the
+lexical C<$_>.
+
+A similar issue may occur in other modules that provide functions which
+take a block as their first argument, like
+
+ foo { ... $_ ...} list
+
+See also: L<http://rt.perl.org/rt3/Public/Bug/Display.html?id=67694>
+
+=item *
+
+readline() returns an empty string instead of undef when it is
+interrupted by a signal.
+
+=item *
+
+The changes in prototype handling break L<Switch>. A patch has been sent
+upstream and will hopefully appear on CPAN soon.
+
+=item *
+
+The upgrade to F<ExtUtils-MakeMaker-6.57_05> has caused
+some tests in the F<Module-Install> distribution on CPAN to
+fail. (Specifically, F<02_mymeta.t> tests 5 and 21; F<18_all_from.t>
+tests 6 and 15; F<19_authors.t> tests 5, 13, 21, and 29; and
+F<20_authors_with_special_characters.t> tests 6, 15, and 23 in version
+1.00 of that distribution now fail.)
+
+=item *
+
+On VMS, C<Time::HiRes> tests will fail due to a bug in the CRTL's
+implementation of C<setitimer>: previous timer values would be cleared
+if a timer expired but not if the timer was reset before expiring. HP
+OpenVMS Engineering have corrected the problem and will release a patch
+in due course (Quix case # QXCM1001115136).
+
+=item *
+
+On VMS, there were a handful of C<Module::Build> test failures we didn't
+get to before the release; please watch CPAN for updates.
+
+=back
+
+=head1 Errata
+
+=head2 keys(), values(), and each() work on arrays
+
+You can now use the keys(), values(), and each() builtins on arrays;
+previously you could use them only on hashes. See L<perlfunc> for details.
+This is actually a change introduced in perl 5.12.0, but it was missed from
+that release's L<perl5120delta>.
+
+=head2 split() and C<@_>
+
+split() no longer modifies C<@_> when called in scalar or void context.
+In void context it now produces a "Useless use of split" warning.
+This was also a perl 5.12.0 change that missed the perldelta.
+
+=head1 Obituary
+
+Randy Kobes, creator of http://kobesearch.cpan.org/ and
+contributor/maintainer to several core Perl toolchain modules, passed
+away on September 18, 2010 after a battle with lung cancer. The community
+was richer for his involvement. He will be missed.
+
+=head1 Acknowledgements
+
+Perl 5.14.0 represents one year of development since
+Perl 5.12.0 and contains nearly 550,000 lines of changes across nearly
+3,000 files from 150 authors and committers.
+
+Perl continues to flourish into its third decade thanks to a vibrant
+community of users and developers. The following people are known to
+have contributed the improvements that became Perl 5.14.0:
+
+Aaron Crane, Abhijit Menon-Sen, Abigail, Ævar Arnfjörð Bjarmason,
+Alastair Douglas, Alexander Alekseev, Alexander Hartmaier, Alexandr
+Ciornii, Alex Davies, Alex Vandiver, Ali Polatel, Allen Smith, Andreas
+König, Andrew Rodland, Andy Armstrong, Andy Dougherty, Aristotle
+Pagaltzis, Arkturuz, Arvan, A. Sinan Unur, Ben Morrow, Bo Lindbergh,
+Boris Ratner, Brad Gilbert, Bram, brian d foy, Brian Phillips, Casey
+West, Charles Bailey, Chas. Owens, Chip Salzenberg, Chris 'BinGOs'
+Williams, chromatic, Craig A. Berry, Curtis Jewell, Dagfinn Ilmari
+Mannsåker, Dan Dascalescu, Dave Rolsky, David Caldwell, David Cantrell,
+David Golden, David Leadbeater, David Mitchell, David Wheeler, Eric
+Brine, Father Chrysostomos, Fingle Nark, Florian Ragwitz, Frank Wiegand,
+Franz Fasching, Gene Sullivan, George Greer, Gerard Goossen, Gisle Aas,
+Goro Fuji, Grant McLean, gregor herrmann, H.Merijn Brand, Hongwen Qiu,
+Hugo van der Sanden, Ian Goodacre, James E Keenan, James Mastros, Jan
+Dubois, Jay Hannah, Jerry D. Hedden, Jesse Vincent, Jim Cromie, Jirka
+Hruška, John Peacock, Joshua ben Jore, Joshua Pritikin, Karl Williamson,
+Kevin Ryde, kmx, Lars Dɪᴇᴄᴋᴏᴡ 迪拉斯, Larwan Berke, Leon Brocard, Leon
+Timmermans, Lubomir Rintel, Lukas Mai, Maik Hentsche, Marty Pauley,
+Marvin Humphrey, Matt Johnson, Matt S Trout, Max Maischein, Michael
+Breen, Michael Fig, Michael G Schwern, Michael Parker, Michael Stevens,
+Michael Witten, Mike Kelly, Moritz Lenz, Nicholas Clark, Nick Cleaton,
+Nick Johnston, Nicolas Kaiser, Niko Tyni, Noirin Shirley, Nuno Carvalho,
+Paul Evans, Paul Green, Paul Johnson, Paul Marquess, Peter J. Holzer,
+Peter John Acklam, Peter Martini, Philippe Bruhat (BooK), Piotr Fusik,
+Rafael Garcia-Suarez, Rainer Tammer, Reini Urban, Renee Baecker, Ricardo
+Signes, Richard Möhn, Richard Soderberg, Rob Hoelz, Robin Barker, Ruslan
+Zakirov, Salvador Fandiño, Salvador Ortiz Garcia, Shlomi Fish, Sinan
+Unur, Sisyphus, Slaven Rezic, Steffen Müller, Steve Hay, Steven
+Schubiger, Steve Peters, Sullivan Beck, Tatsuhiko Miyagawa, Tim Bunce,
+Todd Rinaldo, Tom Christiansen, Tom Hukins, Tony Cook, Tye McQueen,
+Vadim Konovalov, Vernon Lyon, Vincent Pit, Walt Mankowski, Wolfram
+Humann, Yves Orton, Zefram, and Zsbán Ambrus.
+
+This is woefully incomplete as it's automatically generated from version
+control history. In particular, it doesn't include the names of the
+(very much appreciated) contributors who reported issues in previous
+versions of Perl that helped make Perl 5.14.0 better. For a more complete
+list of all of Perl's historical contributors, please see the C<AUTHORS>
+file in the Perl 5.14.0 distribution.
+
+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.
+
+=head1 Reporting Bugs
+
+If you find what you think is a bug, you might check the articles
+recently posted to the comp.lang.perl.misc newsgroup and the Perl
+bug database at http://rt.perl.org/perlbug/ . There may also be
+information at http://www.perl.org/ , the Perl Home Page.
+
+If you believe you have an unreported bug, please run the L<perlbug>
+program included with your release. Be sure to trim your bug down
+to a tiny but sufficient test case. Your bug report, along with the
+output of C<perl -V>, will be sent off to perlbug@perl.org to be
+analysed by the Perl porting team.
+
+If the bug you are reporting has security implications, which make it
+inappropriate to send to a publicly archived mailing list, then please send
+it to perl5-security-report@perl.org. This points to a closed subscription
+unarchived mailing list, which includes all the core committers, who be able
+to help assess the impact of issues, figure out a resolution, and help
+co-ordinate the release of patches to mitigate or fix the problem across all
+platforms on which Perl is supported. Please use this address for
+security issues in the Perl core I<only>, not for modules independently
+distributed on CPAN.
+
+=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