=head1 NAME
-perldelta - what is new for perl v5.14.0
+[ this is a template for a new perldelta file. Any text flagged as
+XXX needs to be processed before release. ]
-=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
-
-XXX Any important notices here
-
-=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}> will continue to mean U+0007, but its use will generate a
-deprecated 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 will not
-have a name in 5.14, but can be referred to by C<\N{U+1F514}>. The plan
-is that in Perl 5.16, C<\N{BELL}> will refer to U+1F514, and so all code
-that uses C<\N{BELL}> should convert by then to using C<\N{ALERT}>,
-C<\N{BEL}>, or C<"\a"> instead.
-
-=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>.
-
-This feature avoids most forms of the "Unicode Bug" (See
-L<perlunicode/The "Unicode Bug"> for details.) If there is a
-possibility that your code will process Unicode strings, you are
-B<strongly> encouraged to use this subpragma to avoid nasty surprises.
-
-=head3 C<\N{I<name>}> and C<charnames> enhancements
-
-=over
-
-=item *
-
-C<\N{}> and C<charnames::vianame> now know about the abbreviated
-character names listed by Unicode, such as NBSP, SHY, LRO, ZWJ, etc., all
-the 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 a number of named character sequences, in which particular sequences
-of code points are given names. C<\N{...}> now recognizes these.
-
-=item *
-
-C<\N{}>, C<charnames::vianame>, C<charnames::viacode> now know about every
-character in Unicode. Previously, they didn't know about the Hangul syllables
-nor a number of CJK (Chinese/Japanese/Korean) characters.
-
-=item *
-
-In the past, it was ineffective to override one of Perl's abbreviations
-with your own custom alias. Now it works.
-
-=item *
-
-You can also create a custom alias of the ordinal of a
-character, known by C<\N{...}>, C<charnames::vianame()>, and
-C<charnames::viacode()>. Previously, an alias had to be to an official
-Unicode character name. This made it impossible to create an alias for
-a code point that had no name, such as those reserved for private
-use.
-
-=item *
-
-A new function, C<charnames::string_vianame()>, has been added.
-This function is a run-time version of C<\N{...}>, returning the string
-of characters whose Unicode name is its parameter. It can handle
-Unicode named character sequences, whereas the pre-existing
-C<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
-others 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 that are 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) warnings have been
-explicitly lexically turned off, outputting or performing a
-Unicode-defined operation (such as upper-casing) on such a code point
-will generate 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 the handling was very inconsistent, and incorrect
-in places. Also, the 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. But inputting or outputting
-them will work the same as for the non-legal Unicode code points, as the
-Unicode standard says they are 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 previously were explicitly opening and reading those
-files, you can download them from
-L<http://www.unicode.org/Public/zipped/6.0.0/>.
-
-=head2 Regular Expressions
-
-=head3 C<(?^...)> construct to signify default modifiers
-
-An ASCII caret (also called a "circumflex accent") C<"^">
-immediately following a C<"(?"> in a regular expression
-now means that the subexpression does not inherit the
-surrounding modifiers such as C</i>, but reverts to the
-Perl defaults. Any modifiers following the caret override the defaults.
-
-The stringification of regular expressions now uses this
-notation. E.g., before, C<qr/hlagh/i> would be stringified as
-C<(?i-xsm:hlagh)>, but now it's stringified as C<(?^i:hlagh)>.
-
-The main purpose of this is to allow tests that rely on the
-stringification not to have to change when new modifiers are added.
-See L<perlre/Extended Patterns>.
-
-=head3 C</d>, C</l>, C</u>, C</a>, and C</aa> modifiers
-
-Four new regular expression modifiers have been added. These are mutually
-exclusive; one only can be turned on at a time.
-
-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.
-
-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.
-
-The C</d> (default) modifier is used to override any C<use locale> and
-C<use feature "unicode_strings"> pragmas that are in effect at the time
-of compiling the regular expression.
-
-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.
-
-The C</aa> modifier is like C</a>, except that, in case-insensitive matching, no ASCII character will match a
-non-ASCII character. For example,
-
- 'k' =~ /\N{KELVIN SIGN}/ai
-
-will match; it won't under C</aa>.
-
-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 Reentrant regular expression engine
-
-It is now safe to use regular expressions within C<(?{...})> and
-C<(??{...})> code blocks inside regular expressions.
-
-These block 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 double-quote-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 $+{...}>
-
-Custom regular expression engines can now determine the return value of
-C<delete> on an entry of C<%+> or C<%->.
-
-=head2 Syntactical Enhancements
-
-=head3 Array and hash container functions accept references
-
-All built-in functions that operate directly on array or hash
-containers now also accept hard references to arrays or hashes:
-
- |----------------------------+---------------------------|
- | Traditional syntax | Terse syntax |
- |----------------------------+---------------------------|
- | push @$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 $arrayref |
- |----------------------------+---------------------------|
-
-This allows these built-in functions to act on long dereferencing chains
-or on the return value of subroutines without needing to wrap them in
-C<@{}> or C<%{}>:
-
- push @{$obj->tags}, $new_tag; # old way
- push $obj->tags, $new_tag; # new way
-
- for ( keys %{$hoh->{genres}{artists}} ) {...} # old way
- for ( keys $hoh->{genres}{artists} ) {...} # new way
-
-For C<push>, C<unshift> and C<splice>, the reference will auto-vivify
-if it is not defined, just as if it were wrapped with C<@{}>.
-
-For C<keys>, C<values>, C<each>, when overloaded dereferencing is
-present, the overloaded dereference is used instead of dereferencing the
-underlying reftype. Warnings are issued about assumptions made in
-ambiguous cases.
-
-=head3 Single term prototype
-
-The C<+> prototype is a special alternative to C<$> that will act 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 only inside that block. 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 { ... }>.
-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 supported this syntax, and it makes
-Perl more internally consistent. A round-trip with C<eval sprintf
-"%#X", 0x10> now returns C<16>, the way C<eval sprintf "%#x", 0x10> does.
-
-=head3 Overridable tie functions
-
-C<tie>, C<tied> and C<untie> can now be overridden [perl #75902].
-
-=head2 Exception Handling
-
-Several changes have been made to the way C<die>, C<warn>, and C<$@>
-behave, in order to make them more reliable and consistent.
-
-When an exception is thrown inside an C<eval>, the exception is no
-longer at risk of being clobbered by code running during unwinding
-(e.g., destructors). Previously, the exception was written into C<$@>
-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 $@> inside an C<eval> will no longer clobber any
-exception thrown in its scope. Previously, the restoration of C<$@> 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
-performed by XS code using the C<G_KEEPERR> flag.
-
-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 file and line number appended. But
-a C<$SIG{__WARN__}> handler will now receive an
-object-based warning as an object, where previously it was passed the
-result of stringifying the object.
-
-=head2 Other Enhancements
-
-=head3 Assignment to C<$0> sets the legacy process name with C<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 ps, top and killall will recognize the name you set when
-assigning to C<$0>. The string you supply will be cut off at 16 bytes;
-this is a limitation imposed by Linux.
-
-=head3 C<srand()> now returns the seed
-
-This allows programs that need to have repeatable results not to have to come
-up with their own seed-generating mechanism. Instead, they can use C<srand()>
-and stash the return value for future use. Typical is a test program which
-has too many combinations to test comprehensively in the time available to it
-each run. It can test a random subset each time and, should there be a failure,
-log the seed used for that run so that it can later be used to reproduce the
-same results.
-
-=head3 printf-like functions understand post-1980 size modifiers
-
-Perl's printf and sprintf operators, and Perl's internal printf replacement
-function, now understand the C90 size modifiers "hh" (C<char>), "z"
-(C<size_t>), and "t" (C<ptrdiff_t>). Also, when compiled with a C99
-compiler, Perl now understands the size modifier "j" (C<intmax_t>).
-
-So, for example, on any modern machine, C<sprintf('%hhd', 257)> returns '1'.
-
-=head3 New global variable C<${^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
-L<perlmod/"BEGIN, UNITCHECK, CHECK, INIT and END">.
-
-=head3 C<-d:-foo> calls C<Devel::foo::unimport>
-
-The syntax C<-dI<B<:>foo>> was extended in 5.6.1 to make C<-dI<:fooB<=bar>>>
-equivalent to C<-MDevel::foo=bar>, which expands
-internally to C<use Devel::foo 'bar';>.
-F<perl> now allows prefixing the module name with C<->, with the same
-semantics as C<-M>, I<i.e.>
-
-=over 4
-
-=item C<-d:-foo>
-
-Equivalent to C<-M-Devel::foo>, expands to
-C<no Devel::foo;>, calls C<< Devel::foo->unimport() >>
-if the method exists.
-
-=item C<-d:-foo=bar>
-
-Equivalent to C<-M-Devel::foo=bar>, expands to C<no Devel::foo 'bar';>,
-calls C<< Devel::foo->unimport('bar') >> if the 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 STDOUT, STDERR and STDIN:
-
- STDOUT->autoflush(1);
-
-Because this on-demand load only happens 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;
- $fh->autoflush(1); # IO::File not loaded
-
-=head3 IPv6 support
-
-The C<Socket> module provides new affordances for IPv6,
-including implementations of the C<Socket::getaddrinfo()> and
-C<Socket::getnameinfo()> functions, along with related constants, and a
-handful of new functions. See L<Socket>.
-
-=head3 DTrace probes now include package name
-
-The DTrace probes now include an additional argument (C<arg3>) which contains
-the package the subroutine being entered or left was compiled in.
-
-For example using the following DTrace script:
-
- perl$target:::sub-entry
- {
- printf("%s::%s\n", copyinstr(arg0), copyinstr(arg3));
- }
-
-and then running:
-
- perl -e'sub test { }; test'
-
-DTrace will print:
-
- main::test
-
-=head2 New C APIs
-
-See L</Internal Changes>.
-
-=head1 Security
-
-=head2 User-defined regular expression properties
-
-In L<perlunicode/"User-Defined Character Properties">, it says 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 \p{foo::bar} could call foo::bar() if it existed. Now this
-convention has been enforced.
-
-Also, Perl no longer allows a tainted regular expression 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 \400-\777
-
-Use of C<\400>-C<\777> in regexes in certain circumstances has given
-different, anomalous behavior than their use in all other
-double-quote-like contexts. Since 5.10.1, a deprecated warning message
-has been raised when this happens. Now, all double-quote-like contexts
-have the same behavior, namely to be equivalent to C<\x{100}> -
-C<\x{1FF}>, with no deprecation warning. Use of these values in the
-command line option C<"-0"> retains the current meaning to slurp input
-files whole; previously, this was documented only for C<"-0777">. It is
-recommended, however, because of various ambiguities, to use the new
-C<\o{...}> construct to represent characters in octal.
-
-=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 than not. And doing
-so leads 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 a number of 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 exact same code points, namely those 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 change to read the new boolean parameter passed to them which is
-non-zero if case-insensitive matching is in effect or 0 otherwise. See
-L<perluniprops/User-Defined Character Properties>.
-
-=head3 \p{} implies Unicode semantics
-
-Now, a Unicode property match specified in the pattern will indicate
-that the pattern is meant for matching according to Unicode rules, the way
-C<\N{}> 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, a regular expression interpolated into another one inherited
-the localeness of the surrounding one, 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 behavior.
-
-=head3 Stringification of regexes has changed
-
-Default regular expression modifiers are now notated by using
-C<(?^...)>. Code relying on the old stringification will fail. The
-purpose of this is so that when new modifiers are added, such code will
-not have to change (after this one time), as 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<(??{...})>) used not
-to inherit any 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 was a bug, which has now been fixed. But
-it has the potential to break
-any code that was relying on it.
-
-=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
-
-The new local array used to be made tied too, which was fairly pointless,
-and 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 that drastically reduce their memory usage 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
-that an empty C<%hash> always returns false in a scalar context.
-
-=head3 Clearing stashes
-
-Stash list assignment C<%foo:: = ()> used to make the stash anonymous
-temporarily while it was being emptied. Consequently, any of its
-subroutines referenced elsewhere would become anonymous (showing up as
-"(unknown)" in C<caller>). Now they retain their package names, such that
-C<caller> will return the original sub name if there is still a reference
-to its typeglob, or "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 (e.g., C<*$glob = \@some_array>) would simply
-assign C<\@some_array> to C<$glob>.
-
-To fix this, the C<*{}> operator (including the 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<*$glob> on the second line returns a new immutable glob. That new
-glob is made an alias to C<*bar>. Then it is discarded. So the second
-assignment has no effect.
-
-See L<http://rt.perl.org/rt3/Public/Bug/Display.html?id=77810> for even
-more detail.
-
-=head3 Magic variables outside the main package
-
-In previous versions of Perl, magic variables like C<$!>, 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).
-
-=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 the 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 will allow the future use of C<:=> as a new
-token.
-
-We find no Perl 5 code on CPAN using this construction, outside the core's
-tests for it, so we believe that this change will have very little impact on
-real-world codebases.
-
-If it is absolutely necessary to have empty attribute lists (for example,
-because of a code generator) then avoid the error by adding a space before
-the C<=>.
-
-=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
-
-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, to avoid
-deadlocks. 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
-childred 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 will now no longer wait for children that
-have been sent a SIGTERM signal. It is up to the parent process to
-waitpid() for these children if child clean-up processing must be
-allowed to finish. However, it is also the responsibility of the
-parent then to avoid the deadlock by making sure the child process
-can't be blocked on I/O either.
-
-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 Policy_sh.SH have
-been fixed, standardizing on the variable names used in config.sh.
-
-This will change the behavior of Policy.sh if you happen to have been
-accidentally relying on its incorrect behavior.
-
-=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 ByteLoader module (which is no longer part of core Perl). This
-had the side effect of breaking various operations on the DATA filehandle,
-including seek()/tell(), and even simply reading from DATA after file handles
-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. Hopefully ByteLoader will 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 a space between a regular expression operator or
-its modifiers and the following word is deprecated. For
-example, C<< m/foo/sand $bar >> will still be parsed
-as C<< m/foo/s and $bar >> but will issue a warning.
-
-=head2 C<\cI<X>>
-
-The backslash-c construct was designed as a way of specifying
-non-printable characters, but there were no restrictions (on ASCII
-platforms) on what the character following the C<c> could be. Now,
-a deprecation warning is raised if that character isn't an ASCII character.
-Also, a deprecation warning is raised for C<"\c{"> (which is the same
-as simply saying C<";">).
-
-=head2 C<"\b{"> and C<"\B{">
-
-In regular expressions, a literal C<"{"> immediately following a C<"\b">
-(not in a bracketed character class) or a C<"\B{"> is now deprecated
-to allow for its future use by Perl itself.
-
-=head2 Deprecation warning added for deprecated-in-core .pl libs
-
-This is a mandatory warning, not obeying -X or lexical warning bits.
-The warning is modelled on that supplied by deprecate.pm for
-deprecated-in-core .pm libraries. It points to the specific CPAN
-distribution that contains the .pl libraries. The CPAN version, of
-course, does not generate the warning.
-
-=head2 List assignment to C<$[>
-
-Assignment to C<$[> was deprecated and started to give warnings in
-Perl version 5.12.0. This version of perl also starts to emit a warning when
-assigning to C<$[> 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)) { ... }
-
-=head2 C<\N{BELL}> is deprecated
-
-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?> is deprecated
-
-C<?PATTERN?> (without the initial 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 in the form of 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 file handle 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)>.
-It is planned to remove this feature in Perl 5.16. Instead use the CPAN module
-L<Unicode::Casing>, which provides improved functionality.
-
-=head2 Deprecated modules
-
-The following modules will be removed from the core distribution in a
-future release, and should be installed from CPAN instead. Distributions
-on CPAN which require these should add them to their prerequisites. The
-core versions of these modules will issue 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 packages for some or all deprecated modules which
-install 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 modules
-in question from CPAN. To install the latest version of all of them,
-just install C<Task::Deprecations::5_14>.
-
-=over
-
-=item L<Devel::DProf>
-
-We strongly recommend that you install and used L<Devel::NYTProf> in
-preference, as it 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 almost all of
-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 is not the case, or it is 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 C<shift;> 5% faster than C<shift @_;>
-on non-threaded perls and 25% faster on threaded.
-
-=head2 Optimisation of regexp engine string comparison work
-
-The 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 gift.
-
-=head2 Regular expression compilation speed-up
-
-Compiling regular expressions has been made faster for the case where upgrading
-the regex to utf8 is necessary but that isn't known when the compilation begins.
-
-=head2 String appending is 100 times faster
-
-When doing a lot of string appending, perl could end up allocating a lot more
-memory than needed in a very inefficient way, if perl was configured to use the
-system's C<malloc> implementation instead of its own.
-
-C<sv_grow>, which is what's being used to allocate more memory if necessary
-when appending to a string, has now been taught how 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 of 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.
-
-However, some non-core code defines C<PERL_CORE>, sometimes intentionally
-to bypass this mechanism for speed reasons, sometimes for other reasons but
-with the inadvertent side effect of bypassing this mechanism. As some of
-this code is widespread in production use, the result is that the core
-I<can't> change the size of members of the interpreter struct, as it will
-break such modules compiled against a previous release on that maintenance
-branch. The upshot is that this mechanism is redundant, and well-behaved
-code is penalised by it. Hence it can and should be removed (and has
-been).
-
-=head2 Freeing weak references
-
-When an object has many weak references to it, freeing that object
-can under some some circumstances take O(N^2) time to free (where N is the
-number of references). The number of circumstances has 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
-
-xhv_fill has been eliminated from struct xpvhv, saving 1 IV per hash and
-on some systems will cause struct xpvhv to become cache-aligned. To avoid
-this memory saving causing a slowdown elsewhere, boolean use of HvFILL
-now calls HvTOTALKEYS instead (which is equivalent) - so while the fill
-data when actually required are now calculated on demand, the cases when
-this needs to be done should be few and far between.
-
-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 only allocate the parts of the C<SV> body
-they actually use, saving some space.
-
-Scalars containing regular expressions now only allocate the part of the C<SV>
-body they actually use, saving some space.
-
-=head2 Memory consumption improvements to Exporter
-
-The @EXPORT_FAIL AV is no longer created unless required, 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 the 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 that they're only done
-when required (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>, ....
-
-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 where 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 *
-
-C<CPAN::Meta::YAML> 0.003 has been added as a dual-life module. It supports a
-subset of YAML sufficient for reading and writing META.yml and 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 *
-
-C<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 (e.g. META.json and META.yml) which describes a
-distribution, its contents, and the requirements for building it and
-installing it. The latest CPAN distribution metadata specification is
-included as C<CPAN::Meta::Spec> and notes on changes in the specification
-over time are given in C<CPAN::Meta::History>.
-
-=item *
-
-C<HTTP::Tiny> 0.011 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 has been added to enable CPAN.pm and CPANPLUS to
-"bootstrap" HTTP access to CPAN using pure Perl without relying on external
-binaries like F<curl> or F<wget>.
-
-=item *
-
-C<JSON::PP> 2.27105 has been added as a dual-life module, for the sake of
-reading F<META.json> files in CPAN distributions.
-
-=item *
-
-C<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 Module::Build::ModuleInfo for use by other module installation
-toolchain components. Module::Build::ModuleInfo has been deprecated in
-favor of this module instead.
-
-=item *
-
-C<Perl::OSType> 1.002 has been added as a dual-life module. It maps Perl
-operating system names (e.g. 'dragonfly' or 'MSWin32') to more generic types
-with standardized names (e.g. "Unix" or "Windows"). It has been refactored
-out of Module::Build and ExtUtils::CBuilder and consolidates such mappings into
-a single location for easier maintenance.
-
-=item *
-
-The following modules were added by the C<Unicode::Collate>
-upgrade. See below for details.
-
-C<Unicode::Collate::CJK::Big5>
-
-C<Unicode::Collate::CJK::GB2312>
-
-C<Unicode::Collate::CJK::JISX0208>
-
-C<Unicode::Collate::CJK::Korean>
-
-C<Unicode::Collate::CJK::Pinyin>
-
-C<Unicode::Collate::CJK::Stroke>
-
-=item *
-
-C<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 as defined in the L<CPAN::Meta::Spec>.
-
-=back
-
-=head2 Updated Modules and Pragma
-
-=over 4
-
-=item *
-
-C<attributes> has been upgraded from version 0.12 to 0.14.
-
-=item *
-
-C<Archive::Extract> has been upgraded from version 0.38 to 0.48.
-
-Updates since 0.38 include: a safe print method that guards
-Archive::Extract from changes to $\; a fix to the tests when run in core
-perl; support for TZ files; a modification for the lzma
-logic to favour IO::Uncompress::Unlzma; and a fix
-for an issue with NetBSD-current and its new unzip
-executable.
-
-=item *
-
-C<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 tar
-
-=item *
-
-A fix so that C<write()> and C<create_archive()>
-close only handles they opened
-
-=item *
-
-A bug was fixed regarding the exit code of extract_archive.
-
-=item *
-
-The C<ptar> 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 ptargrep utility for using regular expressions against
-the contents of files in a tar archive.
-
-=item *
-
-Pax extended headers are now skipped.
-
-=back
-
-=item *
-
-C<Attribute::Handlers> has been upgraded from version 0.87 to 0.89.
-
-=item *
-
-C<autodie> has been upgraded from version 2.06_01 to 2.1001.
-
-=item *
-
-C<AutoLoader> has been upgraded from version 5.70 to 5.71.
-
-=item *
-
-C<B> 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 *
-
-C<B::Concise> has been upgraded from version 0.78 to 0.83.
-
-B::Concise marks rv2sv, rv2av and rv2hv ops with the new OPpDEREF flag
-as "DREFed".
-
-It no longer produces mangled output with the C<-tree> option
-[perl #80632].
-
-=item *
-
-C<B::Debug> has been upgraded from version 1.12 to 1.16.
-
-=item *
-
-C<B::Deparse> has been upgraded from version 0.96 to 1.03.
-
-The deparsing of a 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. Previously the label was emitted
-first, but now the label is emitted last (5.12.1).
-
-The C<no 5.13.2> or similar form is now correctly handled by B::Deparse
-(5.12.3).
-
-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<utf8> pragma) has also been fixed [perl #33752].
-
-=item *
-
-C<B::Lint> has been upgraded from version 1.11_01 to 1.13.
-
-=item *
-
-C<base> has been upgraded from version 2.15 to 2.16.
-
-=item *
-
-C<Benchmark> has been upgraded from version 1.11 to 1.12.
-
-=item *
-
-C<bignum> has been upgraded from version 0.23 to 0.26.
-
-=item *
-
-C<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 C<caller>
-built-in. 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 C<Bizarre copy of ARRAY> caused by modules
-overriding C<caller()> incorrectly (5.12.2).
-
-It now also avoids using regular expressions that cause perl to
-load its Unicode tables, in order to avoid the 'BEGIN not safe after
-errors' error that will ensue if there has been a syntax error
-[perl #82854].
-
-=item *
-
-C<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 *
-
-C<Compress::Raw::Bzip2> has been upgraded from version 2.024 to 2.033.
-
-It has been updated to use bzip2 1.0.6.
-
-=item *
-
-C<Compress::Raw::Zlib> has been upgraded from version 2.024 to 2.033.
-
-=item *
-
-C<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 META/MYMETA.json
-
-=item * support for local::lib
-
-=item * support for 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 bzip2
-
-=item * allow Foo/Bar.pm on the commandline to mean Foo::Bar
-
-=back
-
-=item *
-
-C<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 Config was not recognised as a
-core module dependency. This has been fixed.
-
-CPANPLUS now includes support for META.json and MYMETA.json.
-
-=item *
-
-C<CPANPLUS::Dist::Build> has been upgraded from version 0.46 to 0.54.
-
-=item *
-
-C<Data::Dumper> has been upgraded from version 2.125 to 2.130_02.
-
-The indentation used to be off when C<$Data::Dumper::Terse> was set. This
-has been fixed [perl #73604].
-
-This upgrade also fixes a crash when using custom sort functions that might
-cause the stack to change [perl #74170].
-
-C<Dumpxs> no longer crashes with globs returned by C<*$io_ref>
-[perl #72332].
-
-=item *
-
-C<DB_File> has been upgraded from version 1.820 to 1.821.
-
-=item *
-
-C<DBM_Filter> has been upgraded from version 0.03 to 0.04.
-
-=item *
-
-C<Devel::DProf> has been upgraded from version 20080331.00 to 20110228.00.
-
-Merely loading C<Devel::DProf> now no longer triggers profiling to start.
-C<use Devel::DProf> and C<perl -d:DProf ...> still behave as before and start
-the profiler.
-
-NOTE: C<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 *
-
-C<Devel::Peek> has been upgraded from version 1.04 to 1.07.
-
-=item *
-
-C<Devel::SelfStubber> has been upgraded from version 1.03 to 1.05.
-
-=item *
-
-C<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 *
-
-C<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 *
-
-C<Digest::SHA> has been upgraded from version 5.47 to 5.61.
-
-C<shasum> now more closely mimics C<sha1sum>/C<md5sum>.
-
-C<Addfile> accepts all POSIX filenames.
-
-New SHA-512/224 and SHA-512/256 transforms (ref. NIST Draft FIPS 180-4
-[February 2011])
-
-=item *
-
-C<DirHandle> has been upgraded from version 1.03 to 1.04.
-
-=item *
-
-C<Dumpvalue> has been upgraded from version 1.13 to 1.16.
-
-=item *
-
-C<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 AutoLoader; hence it no longer
-produces weird error messages for unsuccessful method calls on classes that
-inherit from DynaLoader [perl #84358].
-
-=item *
-
-C<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; in those cases where it warned, all 66 warn.
-
-=item *
-
-C<Env> has been upgraded from version 1.01 to 1.02.
-
-=item *
-
-C<Errno> has been upgraded from version 1.11 to 1.13.
-
-The implementation of C<Errno> has been refactored to use about 55% less memory.
-
-On some platforms with unusual header files, like Win32/gcc using mingw64
-headers, some constants which weren't actually error numbers have been exposed
-by C<Errno>. This has been fixed [perl #77416].
-
-=item *
-
-C<Exporter> has been upgraded from version 5.64_01 to 5.64_03.
-
-Exporter no longer overrides C<$SIG{__WARN__}> [perl #74472]
-
-=item *
-
-C<ExtUtils::CBuilder> has been upgraded from version 0.27 to 0.280202.
-
-=item *
-
-C<ExtUtils::Command> has been upgraded from version 1.16 to 1.17.
-
-=item *
-
-C<ExtUtils::Constant> has been upgraded from 0.22 to 0.23.
-
-The C<AUTOLOAD> helper code generated by C<ExtUtils::Constant::ProxySubs>
-can now C<croak> for missing constants, or generate a complete C<AUTOLOAD>
-subroutine in XS, allowing simplification of many modules that use it
-(C<Fcntl>, C<File::Glob>, C<GDBM_File>, C<I18N::Langinfo>, C<POSIX>,
-C<Socket>).
-
-C<ExtUtils::Constant::ProxySubs> can now optionally push the names of all
-constants onto the package's C<@EXPORT_OK>.
-
-=item *
-
-C<ExtUtils::Install> has been upgraded from version 1.55 to 1.56.
-
-=item *
-
-C<ExtUtils::MakeMaker> has been upgraded from version 6.56 to 6.57_05.
-
-=item *
-
-C<ExtUtils::Manifest> has been upgraded from version 1.57 to 1.58.
-
-=item *
-
-C<ExtUtils::ParseXS> has been upgraded from version 2.21 to 2.2210.
-
-=item *
-
-C<Fcntl> has been upgraded from version 1.06 to 1.11.
-
-=item *
-
-C<File::Basename> has been upgraded from version 2.78 to 2.81.
-
-=item *
-
-C<File::CheckTree> has been upgraded from version 4.4 to 4.41.
-
-=item *
-
-C<File::Copy> has been upgraded from version 2.17 to 2.21.
-
-=item *
-
-C<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 the file names
-returned when the pattern is a relative glob with a drive specification,
-like F<c:*.pl> [perl #71712].
-
-=item *
-
-C<File::Fetch> has been upgraded from version 0.24 to 0.32.
-
-C<HTTP::Lite> is now supported for 'http' scheme.
-
-The C<fetch> utility is supported on FreeBSD, NetBSD and
-Dragonfly BSD for the C<http> and C<ftp> schemes.
-
-=item *
-
-C<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 *
-
-C<File::Glob> has been upgraded from version 1.07 to 1.12.
-
-=item *
-
-C<File::Spec> has been upgraded from version 3.31 to 3.33.
-
-Several portability fixes were made in C<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; C<catpath()> returns
-an empty directory rather than the current directory if the input directory
-name is empty; C<abs2rel()> properly handles Unix-style input (5.12.2).
-
-=item *
-
-C<File::stat> has been upgraded from 1.02 to 1.05.
-
-The C<-x> and C<-X> file test operators now work correctly under the root
-user.
-
-=item *
-
-C<Filter::Simple> has been upgraded from version 0.84 to 0.86.
-
-=item *
-
-C<GDBM_File> has been upgraded from 1.10 to 1.14.
-
-This fixes a memory leak when DBM filters are used.
-
-=item *
-
-C<Hash::Util> has been upgraded from 0.07 to 0.11.
-
-Hash::Util no longer emits spurious "uninitialized" warnings when
-recursively locking hashes that have undefined values [perl #74280].
-
-=item *
-
-C<Hash::Util::FieldHash> has been upgraded from version 1.04 to 1.09.
-
-=item *
-
-C<I18N::Collate> has been upgraded from version 1.01 to 1.02.
-
-=item *
-
-C<I18N::Langinfo> has been upgraded from version 0.03 to 0.08.
-
-C<langinfo()> now defaults to using C<$_> if there is no argument given, just
-as the documentation has always claimed.
-
-=item *
-
-C<I18N::LangTags> has been upgraded from version 0.35 to 0.35_01.
-
-=item *
-
-C<if> has been upgraded from version 0.05 to 0.0601.
-
-=item *
-
-C<IO> has been upgraded from version 1.25_02 to 1.25_04.
-
-This version of C<IO> includes a new C<IO::Select>, which now allows IO::Handle
-objects (and objects in derived classes) to be removed from an IO::Select set
-even if the underlying file descriptor is closed or invalid.
-
-=item *
-
-C<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 *
-
-C<IPC::Open3> has been upgraded from 1.05 to 1.09.
-
-C<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 C<xclose> routine now knows how to handle file descriptors, as
-documented, so duplicating STDIN in a child process using its file
-descriptor now works [perl #76474].
-
-=item *
-
-C<IPC::SysV> has been upgraded from version 2.01 to 2.03.
-
-=item *
-
-C<lib> has been upgraded from version 0.62 to 0.63.
-
-=item *
-
-C<Locale::Maketext> has been upgraded from version 1.14 to 1.19.
-
-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 will now back up and restore C<$@> so that error
-messages are not suppressed (CPAN RT #34182).
-
-=item *
-
-C<Log::Message> has been upgraded from version 0.02 to 0.04.
-
-=item *
-
-C<Log::Message::Simple> has been upgraded from version 0.06 to 0.08.
-
-=item *
-
-C<Math::BigInt> has been upgraded from version 1.89_01 to 1.994.
-
-This fixes, among other things, incorrect results when computing binomial
-coefficients [perl #77640].
-
-It also prevents C<sqrt($int)> from crashing under C<use bigrat;>
-[perl #73534].
-
-=item *
-
-C<Math::BigInt::FastCalc> has been upgraded from version 0.19 to 0.28.
-
-=item *
-
-C<Math::BigRat> has been upgraded from version 0.24 to 0.26_02.
-
-=item *
-
-C<Memoize> has been upgraded from version 1.01_03 to 1.02.
-
-=item *
-
-C<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 C<encode_base64url> and C<decode_base64url> functions to process
-the base64 scheme for "URL applications".
-
-=item *
-
-C<Module::Build> has been upgraded from version 0.3603 to 0.3800.
-
-A notable change is the deprecation of several modules.
-Module::Build::Version has been deprecated and Module::Build now relies
-directly upon L<version>. Module::Build::ModuleInfo has been deprecated in
-favor of a standalone copy of it called L<Module::Metadata>.
-Module::Build::YAML has been deprecated in favor of L<CPAN::Meta::YAML>.
-
-Module::Build now also generates META.json and MYMETA.json files
-in accordance with version 2 of the CPAN distribution metadata specification,
-L<CPAN::Meta::Spec>. The older format META.yml and MYMETA.yml files are
-still generated, as well.
-
-=item *
-
-C<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 C<Module::CoreList> confused it with C<VMS::Filespec>, which actually
-is a core module as of perl 5.8.7.
-
-=item *
-
-C<Module::Load> has been upgraded from version 0.16 to 0.18.
-
-=item *
-
-C<Module::Load::Conditional> has been upgraded from version 0.34 to 0.44.
-
-=item *
-
-C<mro> has been upgraded from version 1.02 to 1.07.
-
-=item *
-
-C<NDBM_File> has been upgraded from version 1.08 to 1.12.
-
-This fixes a memory leak when DBM filters are used.
-
-=item *
-
-C<Net::Ping> has been upgraded from version 2.36 to 2.38.
-
-=item *
-
-C<NEXT> has been upgraded from version 0.64 to 0.65.
-
-=item *
-
-C<Object::Accessor> has been upgraded from version 0.36 to 0.38.
-
-=item *
-
-C<ODBM_File> have been upgraded from version 1.07 to 1.10.
-
-This fixes a memory leak when DBM filters are used.
-
-=item *
-
-C<Opcode> has been upgraded from version 1.15 to 1.18.
-
-=item *
-
-C<overload> 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 *
-
-C<Params::Check> has been upgraded from version 0.26 to 0.28.
-
-=item *
-
-C<parent> has been upgraded from version 0.223 to 0.225.
-
-=item *
-
-C<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 *
-
-C<PerlIO::encoding> has been upgraded from version 0.12 to 0.14.
-
-=item *
-
-C<PerlIO::scalar> has been upgraded from 0.07 to 0.11.
-
-A C<read> after a C<seek> beyond the end of the string no longer thinks it
-has data to read [perl #78716].
-
-=item *
-
-C<PerlIO::via> has been upgraded from version 0.09 to 0.11.
-
-=item *
-
-C<Pod::Html> has been upgraded from version 1.09 to 1.1.
-
-=item *
-
-C<Pod::LaTeX> has been upgraded from version 0.58 to 0.59.
-
-=item *
-
-C<Pod::Perldoc> has been upgraded from version 3.15_02 to 3.15_03.
-
-=item *
-
-C<Pod::Simple> has been upgraded from version 3.13 to 3.16.
-
-=item *
-
-C<POSIX> has been upgraded from 1.19 to 1.24.
-
-It now includes constants for POSIX signal constants.
-
-=item *
-
-C<re> has been upgraded from version 0.11 to 0.17.
-
-New C<use re "/flags"> pragma
-
-The C<regmust> function used to crash when called on a regular expression
-belonging to a pluggable engine. Now it croaks instead.
-
-C<regmust> no longer leaks memory.
-
-=item *
-
-C<Safe> has been upgraded from version 2.25 to 2.29.
-
-Coderefs returned by C<reval()> and C<rdo()> are now wrapped via
-C<wrap_code_refs> (5.12.1).
-
-This fixes a possible infinite loop when looking for coderefs.
-
-It adds several version::vxs::* routines to the default share.
-
-=item *
-
-C<SDBM_File> has been upgraded from version 1.06 to 1.09.
-
-=item *
-
-C<SelfLoader> has been upgraded from 1.17 to 1.18.
-
-It now works in taint mode [perl #72062].
-
-=item *
-
-C<sigtrap> 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 *
-
-C<Socket> has been upgraded from version 1.87 to 1.94.
-
-See L</IPv6 support>, above.
-
-=item *
-
-C<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 Storable minor version
-number changed as a result, meaning that
-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 *
-
-C<Sys::Hostname> has been upgraded from version 1.11 to 1.16.
-
-=item *
-
-C<Term::ANSIColor> has been upgraded from version 2.02 to 3.00.
-
-=item *
-
-C<Term::UI> has been upgraded from version 0.20 to 0.26.
-
-=item *
-
-C<Test::Harness> has been upgraded from version 3.17 to 3.23.
-
-=item *
-
-C<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 C<done_testing()> added to them.
-
-=item *
-
-C<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 *
-
-C<Thread::Queue> has been upgraded from version 2.11 to 2.12.
-
-=item *
-
-C<threads> has been upgraded from version 1.75 to 1.83.
-
-=item *
-
-C<threads::shared> has been upgraded from version 1.32 to 1.36.
-
-=item *
-
-C<Tie::Hash> has been upgraded from version 1.03 to 1.04.
-
-Calling C<< Tie::Hash-E<gt>TIEHASH() >> used to loop forever. Now it C<croak>s.
-
-=item *
-
-C<Tie::Hash::NamedCapture> has been upgraded from version 0.06 to 0.08.
-
-=item *
-
-C<Tie::RefHash> has been upgraded from version 1.38 to 1.39.
-
-=item *
-
-C<Time::HiRes> has been upgraded from version 1.9719 to 1.9721_01.
-
-=item *
-
-C<Time::Local> has been upgraded from version 1.1901_01 to 1.2000.
-
-=item *
-
-C<Time::Piece> has been upgraded from version 1.15_01 to 1.20_01.
-
-=item *
-
-C<Unicode::Collate> has been upgraded from version 0.52_01 to 0.73.
-
-Unicode::Collate has been updated to use Unicode 6.0.0.
-
-Unicode::Collate::Locale now supports a plethora of new locales: 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 zh__stroke.
-
-The following modules have been added:
-
-C<Unicode::Collate::CJK::Big5> for C<zh__big5han> which makes
-tailoring of CJK Unified Ideographs in the order of CLDR's big5han ordering.
-
-C<Unicode::Collate::CJK::GB2312> for C<zh__gb2312han> which makes
-tailoring of CJK Unified Ideographs in the order of CLDR's gb2312han ordering.
-
-C<Unicode::Collate::CJK::JISX0208> which makes tailoring of 6355 kanji
-(CJK Unified Ideographs) in the JIS X 0208 order.
-
-C<Unicode::Collate::CJK::Korean> which makes tailoring of CJK Unified Ideographs
-in the order of CLDR's Korean ordering.
-
-C<Unicode::Collate::CJK::Pinyin> for C<zh__pinyin> which makes
-tailoring of CJK Unified Ideographs in the order of CLDR's pinyin ordering.
-
-C<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 *
-
-C<Unicode::Normalize> has been upgraded from version 1.03 to 1.10.
-
-=item *
-
-C<Unicode::UCD> has been upgraded from version 0.27 to 0.32.
-
-A new function, C<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 a number of bug fixes:
-
-=over 4
-
-=item charinfo()
-
-=over 4
-
-=item *
-
-It is now updated to Unicode Version 6 with Corrigendum #8, except,
-as with Perl 5.14, the code point at U+1F514 has no name.
-
-=item *
-
-The 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 *
-
-The CJK (Chinese-Japanese-Korean) code points U+2A700 to U+2B734
-and U+2B740 to U+2B81D are now properly handled.
-
-=item *
-
-The numeric values are now output for those CJK code points that have them.
-
-=item *
-
-The names that are 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 *
-
-C<version> has been upgraded from 0.82 to 0.88.
-
-Due to a bug, now fixed, the C<is_strict> and C<is_lax> functions did not
-work when exported (5.12.1).
-
-=item *
-
-C<warnings> has been upgraded from version 1.09 to 1.12.
-
-Calling C<use warnings> without arguments is now significantly more efficient.
-
-=item *
-
-C<warnings::register> have been upgraded from version 1.01 to 1.02.
-
-It is now possible to register warning categories other than the names of
-packages using C<warnings::register>. See L<perllexwarn> for more information.
-
-=item *
-
-C<XSLoader> has been upgraded from version 0.10 to 0.13.
-
-=item *
-
-C<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 ':LOCAL' failed to
-identify objects connected to the local symbol table.
-
-=item *
-
-C<Win32> has been upgraded from version 0.39 to 0.44.
-
-This release has several new functions: C<Win32::GetSystemMetrics>,
-C<Win32::GetProductInfo>, C<Win32::GetOSDisplayName>.
-
-The names returned by C<Win32::GetOSName> and C<Win32::GetOSDisplayName>
-have been corrected.
-
-=item *
-
-C<XS::Typemap> has been upgraded from version 0.03 to 0.05.
-
-=back
-
-=head2 Removed Modules and Pragmata
-
-The following modules have been removed from the core distribution, and if
-needed should be installed from CPAN instead.
-
-=over
-
-=item *
-
-C<Class::ISA> has been removed from the Perl core. Prior version was 0.36.
-
-=item *
-
-C<Pod::Plainer> has been removed from the Perl core. Prior version was 1.02.
-
-=item *
-
-C<Switch> has been removed from the Perl core. Prior version was 2.16.
-
-=back
-
-The removal of C<Shell> has been deferred until after 5.14, as the
-implementation of C<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 pod2man man page.
-
-=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 perlmodlib page that came with Perl 5.12.0 was missing a lot of
-modules, due to a bug in the script that generates the list. This has been
-fixed [perl #74332] (5.12.1).
-
-=head3 Replace wrong tr/// table in L<perlebcdic>
-
-L<perlebcdic> contains a helpful table to use in tr/// to convert
-between EBCDIC and Latin1/ASCII. Unfortunately, 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 changed to its inverse, and the sample code changed
-to correspond, as this is easier for the person trying to follow the
-instructions since deriving the old table is somewhat more complicated.
-
-The table has also been changed to hex from octal, as that is more the norm
-these days, and the recipes in the pod altered to print out leading
-zeros to make all the 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.
-
-=head3 INSTALL explicitly states the requirement for C89
-
-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 C<-0I<NNN>> switch
-
-In L<perlrun>, the behavior of the C<-0NNN> switch for C<-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%s} resolved to %c%s%s|perldiag/"Ambiguous use of %c{%s%s} resolved to %c%s%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 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> and perlrepository documents have been heavily edited and
-split up into several new documents.
-
-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 only been
-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 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, i.e. 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....
-
-=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 so as 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 *
-
-C<warn> and C<die> now produce 'Wide character' warnings when fed a
-character outside the byte range if 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 C<gethostbyaddr>, C<gethostbyname> and
-C<gethostent> functions were implemented on a given platform, they would
-all die with the message 'Unsupported socket function "gethostent" called',
-with analogous messages for C<getnet*> and C<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. E.g., "\q{" is now emitted instead of "\q".
-
-=back
-
-=head1 Utility Changes
-
-=head3 L<perlbug>
-
-=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. Now it does include 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 C<-d>
-and C<-v> options (5.12.2).
-
-=back
-
-=head3 L<perl5db.pl>
-
-=over
-
-=item *
-
-The remote terminal works after forking and spawns new sessions - one
-for each 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
-$(CCHOME)\mingw\include and \lib rather than immediately below $(CCHOME).
-
-This means the 'incpath', 'libpth', 'ldflags', 'lddlflags' and
-'ldflags_nolargefiles' values in Config.pm and Config_heavy.pl are now
-set correctly.
-
-=item *
-
-'make test.valgrind' has been adjusted to account for cpan/dist/ext
-separation.
-
-=item *
-
-On compilers that support it, C<-Wwrite-strings> is now added to cflags by
-default.
-
-=item *
-
-The C<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 in the neighborhood
-of 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 C<File::Copy> tests on partitions it detects to be 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 *
-
-MakeMaker has been updated to build man pages 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, which is e.g. needed for FFI's
-
-=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 -Duse64bitint without promoting to 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
-C<setregid>, C<setreuid>, C<setrgid> and C<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 libperl.so on MirBSD (the
-default config), it would work up to the installation; however, once
-installed, it would be unable to find libperl. So 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's malloc the
-default.
-
-=back
-
-=head3 Recent OpenBSDs now use perl's malloc
-
-=over
-
-=item *
-
-OpenBSD E<gt> 3.7 has a new malloc implementation which is 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 *
-
-It's now possible to build extensions on older (pre 7.3-2) VMS systems.
-
-DCL symbol length was limited to 1K up until about seven years or
-so ago, but there was no particularly deep reason to prevent those
-older systems from configuring and building Perl (5.12.1).
-
-=item *
-
-We fixed the previously-broken C<-Uuseperlio> build on VMS.
-
-We were checking a variable that doesn't exist in the non-default
-case of disabling perlio. Now we only look at it when it exists (5.12.1).
-
-=item *
-
-We fixed the -Uuseperlio command-line option in configure.com.
-
-Formerly it only worked if you went through all the questions
-interactively and explicitly answered no (5.12.1).
-
-=item *
-
-C<PerlIOUnix_open> now honours the default permissions on VMS.
-
-When C<perlio> became the default and C<unixio> 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.
-
-To avoid this, C<0777> is now passed as the permissions to C<open()>. In the
-VMS 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 *
-
-Spurious record boundaries are no longer
-introduced by the PerlIO layer during output (5.12.3).
-
-=item *
-
-The shortening of symbols longer than 31 characters in the C sources is
-now done by the compiler rather than by xsubpp (which could only do so
-for generated symbols in XS code).
-
-=item *
-
-Record-oriented files (record format variable or variable with fixed control)
-opened for write by the 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 C<Perl_rename()> due to a double allocation has been
-fixed (5.12.2).
-
-=item *
-
-A memory leak in C<vms_fid_to_name()> (used by C<realpath()> and
-C<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> will now
-be 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 C<crypt()>, or to build with no
-C<crypt()> at all, has been removed. Perl supplies its own C<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 C<Perl_clone_params_new()>, and free them with
-C<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 statements or multiple
-statements:
-
-=over
-
-=item *
-
-C<parse_fullstmt> parses a complete Perl statement.
+perldelta - what is new for perl v5.15.0
-=item *
+=for comment
+This has been completed up to 571f0e8.
-C<parse_stmtseq> parses a sequence of statements, up
-to closing brace or EOF.
+=head1 DESCRIPTION
-=item *
+This document describes differences between the 5.15.0 release and
+the 5.14.0 release.
-C<parse_block> parses a block [perl #78222].
+If you are upgrading from an earlier release such as 5.YYY.YYY, first read
+L<perl5YYYdelta>, which describes differences between 5.ZZZ.ZZZ and
+5.YYY.YYY.
-=item *
+Some of the changes have been included in Perl 5.14.1. These are
+indicated with a "(5.14.1)" marker.
-C<parse_barestmt> parses a statement
-without a label.
+XXX compare this perldelta to 5.14.1 and double check the notation
-=item *
+=head1 Notice
-C<parse_label> parses a statement label, separate from statements.
+XXX Any important notices here
-=back
+=head1 Core Enhancements
-The
-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>
-functions have been added to the API. They perform
-recursive-descent parsing of expressions at various precedence levels.
-They are expected to be used by syntax plugins.
+XXX New core language features go here. Summarise user-visible core language
+enhancements. Particularly prominent performance optimisations could go
+here, but most should go in the L</Performance Enhancements> section.
-See L<perlapi> for details.
+[ List each enhancement as a =head2 entry ]
-=head3 Hints hash API
+=head2 C<CORE::> works on all keywords
-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.
+The C<CORE::> prefix can now be used on keywords enabled by
+L<feature.pm|feature>, even outside the scope of C<use feature>.
-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>.
+=head2 C<continue> no longer requires the "switch" feature
-=head3 C interface to C<caller()>
+The C<continue> keyword has two meanings. It can introduce a C<continue>
+block after a loop, or it can exit the current C<when> block. Up till now,
+the latter meaning was only valid with the "switch" feature enabled, and
+was a syntax error otherwise. Since the main purpose of feature.pm is to
+avoid conflicts with user-defined subroutines, there is no reason for
+C<continue> to depend on it.
-The C<caller_cx> function has been added as an XSUB-writer's equivalent of
-C<caller()>. See L<perlapi> for details.
+=head2 C<$$> can be assigned to
-=head3 Custom per-subroutine check hooks
+C<$$> was made read-only in Perl 5.8.0. But only sometimes: C<local $$>
+would make it writable again. Some CPAN modules were using C<local $$> or
+XS code to bypass the read-only check, so there is no reason to keep C<$$>
+read-only. (This change also allowed a bug to be fixed while maintaining
+backward compatibility.)
-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>.
+=head2 Features inside the debugger
-To help in writing custom check hooks, several subtasks within standard
-C<entersub> op checking have been separated out and exposed in the API.
+The current Perl's feature bundle is now enabled for commands entered in
+the interactive debugger.
-=head3 Improved support for custom OPs
+=head2 C<\N{...}> can now have Unicode loose name matching
-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>.
+This is described in the C<charnames> item in
+L</Updated Modules and Pragmata> below.
-C<xop_class> is one of the OA_*OP constants, and 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>.
+=head2 Breakpoints with file names
-See L<perlguts/Custom Operators> and L<perlapi/Custom Operators> for more
-detail.
+The debugger's "b" command for setting breakpoints now allows a line number
+to be prefixed with a file name. See
+L<perldebug/"b [file]:[line] [condition]">.
-The old C<PL_custom_op_names>/C<PL_custom_op_descs> interface is still
-supported but discouraged.
+=head1 Security
-=head3 Scope hooks
+XXX Any security-related notices go here. In particular, any security
+vulnerabilities closed should be noted here rather than in the
+L</Selected Bug Fixes> section.
-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">.
+[ List each security issue as a =head2 entry ]
-=head3 The recursive part of the peephole optimizer is now hookable
+=head1 Incompatible Changes
-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.
+[ List each incompatible change as a =head2 entry ]
-=head3 New non-magical variants of existing functions
+=head2 Tying scalars that hold typeglobs
-The following functions/macros have been added to the API. The C<*_nomg>
-macros are equivalent to their non-_nomg variants, except that they ignore
-get-magic. Those ending in C<_flags> allow one to specify whether
-get-magic is processed.
+Attempting to tie a scalar after a typeglob was assigned to it would
+instead tie the handle in the typeglob's IO slot. This meant that it was
+impossible to tie the scalar itself. Similar problems affected C<tied> and
+C<untie>: C<tied $scalar> would return false on a tied scalar if the last
+thing returned was a typeglob, and C<untie $scalar> on such a tied scalar
+would do nothing.
- sv_2bool_flags
- SvTRUE_nomg
- sv_2nv_flags
- SvNV_nomg
- sv_cmp_flags
- sv_cmp_locale_flags
- sv_eq_flags
- sv_collxfrm_flags
+We fixed this problem before Perl 5.14.0, but it caused problems with some
+CPAN modules, so we put in a deprecation cycle instead.
-In some of these cases, the non-_flags functions have
-been replaced with wrappers around the new functions.
+Now the deprecation has been removed and this bug has been fixed. So
+C<tie $scalar> will always tie the scalar, not the handle it holds. To tie
+the handle, use C<tie *$scalar> (with an explicit asterisk). The same
+applies to C<tied *$scalar> and C<untie *$scalar>.
-=head3 pv/pvs/sv versions of existing functions
+=head2 IPC::Open3 no longer provides C<xfork()>, C<xclose_on_exec()>
+and C<xpipe_anon()>
-Many functions ending with pvn now have equivalent pv/pvs/sv versions.
+All three functions were private, undocumented and unexported. They do
+not appear to be used by any code on CPAN. Two have been inlined and one
+deleted entirely.
-=head3 List op-building functions
+=head2 C<$$> no longer caches PID
-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>.
+Previously, if one embeds Perl or uses XS and calls fork(3) from C, Perls
+notion of C<$$> could go out of sync with what getpid() returns. By always
+fetching the value of C<$$> via getpid(), this potential bug is eliminated.
+Code that depends on the caching behavior will break. As describe in L</Core
+Enhancements>, C<$$> is now writeable, but it will be reset during a fork.
-=head3 C<LINKLIST>
+=head1 Deprecations
-The L<LINKLIST|perlapi/LINKLIST> macro, part of op building that
-constructs the execution-order op chain, has been added to the API.
+XXX Any deprecated features, syntax, modules etc. should be listed here.
+In particular, deprecated modules should be listed here even if they are
+listed as an updated module in the L</Modules and Pragmata> section.
-=head3 Localisation functions
+[ List each deprecation as a =head2 entry ]
-The C<save_freeop>, C<save_op>, C<save_pushi32ptr> and C<save_pushptrptr>
-functions have been added to the API.
+=head1 Performance Enhancements
-=head3 Stash names
+XXX Changes which enhance performance without changing behaviour go here. There
+may well be none in a stable release.
-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>).
+[ List each enhancement as a =item entry ]
-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.
+=over 4
-=head3 New functions for finding and removing magic
+=item *
-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
-C<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.
+XXX
-=head3 C<find_rundefsv>
+=back
-This function returns the SV representing C<$_>, whether it's lexical
-or dynamic.
+=head1 Modules and Pragmata
-=head3 C<Perl_croak_no_modify>
+XXX All changes to installed files in F<cpan/>, F<dist/>, F<ext/> and F<lib/>
+go here. If Module::CoreList is updated, generate an initial draft of the
+following sections using F<Porting/corelist-perldelta.pl>, which prints stub
+entries to STDOUT. Results can be pasted in place of the '=head2' entries
+below. A paragraph summary for important changes should then be added by hand.
+In an ideal world, dual-life modules would have a F<Changes> file that could be
+cribbed.
-C<Perl_croak_no_modify()> is short-hand for
-C<Perl_croak("%s", PL_no_modify)>.
+[ Within each section, list entries as a =item entry ]
-=head3 C<PERL_STATIC_INLINE> define
+=head2 New Modules and Pragmata
-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>.
+=over 4
-C<HAS_STATIC_INLINE> can be used to check if the compiler actually supports
-inline functions.
+=item *
-=head3 New C<pv_escape> option for hexadecimal escapes
+XXX
-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.
+=back
-=head3 C<lex_start>
+=head2 Updated Modules and Pragmata
-C<lex_start> has been added to the API, but is considered experimental.
+=over 4
-=head3 C<op_scope()> and C<op_lvalue()>
+=item *
-The C<op_scope()> and C<op_lvalue()> functions have been added to the API,
-but are considered experimental.
+L<constant> has been updated from version 1.21 to 1.22.
-=head2 C API Changes
+=item *
-=head3 C<PERL_POLLUTE> has been removed
+L<Archive::Extract> has been upgraded from version 0.48 to version 0.52
-The option to define C<PERL_POLLUTE> to expose older 5.005 symbols for
-backwards compatibility has been removed. It's use was always discouraged,
-and MakeMaker contains a more specific escape hatch:
+Includes a fix for FreeBSD to only use C<unzip> if it is located in
+C</usr/local/bin>, as FreeBSD 9.0 will ship with a limited C<unzip> in
+C</usr/bin>.
- perl Makefile.PL POLLUTE=1
+=item *
-This can be used for modules that have not been upgraded to 5.6 naming
-conventions (and really should be completely obsolete by now).
+L<Attribute::Handlers> updated from version 0.88 to 0.91
-=head3 Check API compatibility when loading XS modules
+=item *
-When perl's API changes in incompatible ways (which usually happens between
-major releases), XS modules compiled for previous versions of perl will not
-work anymore. They will need to be recompiled against the new perl.
+L<B> has been upgraded from version 1.29 to version 1.30.
-In order to ensure that modules are recompiled, and to prevent users from
-accidentally loading modules compiled for old perls into newer ones, the
-C<XS_APIVERSION_BOOTCHECK> macro has been added. 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.
+=item *
-=head3 Perl_fetch_cop_label
+L<B::Deparse> has been upgraded from version 1.03 to 1.05.
-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.
+It addresses two regressions in Perl 5.14.0:
-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.)
+=over
-=head3 GvCV() and GvGP() are no longer lvalues
+=item *
-The new GvCV_set() and GvGP_set() macros are now provided to replace
-assignment to those two macros.
+Deparsing of the C<glob> operator and its diamond (C<< <> >>) form now
+works again [RT #90898] (5.14.1).
-This allows a future commit to eliminate some backref magic between GV
-and CVs, which will require complete control over assignment to the
-gp_cv slot.
+=item *
-=head3 CvGV() is no longer an lvalue
+The presence of subroutines named C<::::> or C<::::::> no longer causes
+B::Deparse to hang (5.14.1).
-Under some circumstances, the C<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 perform 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).
+=back
-=head3 CvSTASH() is no longer an lvalue
+Plus a few other bugs:
-The C<CvSTASH()> macro can now only be used as an rvalue. C<CvSTASH_set()>
-has been added to replace assignment to C<CvSTASH()>. This is to ensure
-that backreferences are handled properly. These macros are not part of the
-API.
+=over
-=head3 Calling conventions for C<newFOROP> and C<newWHILEOP>
+=item *
-The way the parser handles labels has been cleaned up and refactored. As a
-result, the C<newFOROP()> constructor function no longer takes a parameter
-stating what label is to go in the state op.
+Deparsing of handle C<keys>, C<each> and C<value> with a scalar argument
+now works [RT #91008].
-The C<newWHILEOP()> and C<newFOROP()> functions no longer accept a line
-number as a parameter.
+=item *
-=head3 Flags passed to C<uvuni_to_utf8_flags> and C<utf8n_to_uvuni>
+C<readpipe> followed by a complex expression (as opposed to a simple scalar
+variable) now works.
-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 L</Selected Bug Fixes>.
+=item *
-XXX Which bugs in particular? Selected Bug Fixes is too long for this link
-to be meaningful right now
-I don't see the bugs in that section currently -- khw
+It now puts C<CORE::> in front of overridable core keywords if they
+conflict with user-defined subroutines.
-=head2 Deprecated C APIs
+=item *
-=over
+Deparsing assignment to an lvalue method specified as a variable
+(C<< $obj->$method = ... >>) used not to work [RT #62498].
-=item C<Perl_ptr_table_clear>
+=back
-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 *
-=item C<sv_compile_2op>
+L<CGI> has been upgraded from version 3.52 to version 3.54
-The C<sv_compile_2op()> API function is now deprecated. Searches suggest
-that nothing on CPAN is using it, so this should have zero impact.
+The DELETE HTTP verb is now supported.
-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 *
-=item C<find_rundefsvoffset>
+L<Compress::Zlib> has been upgraded from version 2.033 to version 2.035
-The C<find_rundefsvoffset> function has been deprecated. It appeared that
-its design was insufficient for reliably getting the lexical C<$_> at
-run-time.
+=item *
-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.
+L<Compress::Raw::Bzip2> has been upgraded from version 2.033 to version 2.035
-=item C<CALL_FPTR> and C<CPERLscope>
+=item *
-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.
+L<Compress::Raw::Zlib> has been upgraded from version 2.033 to version 2.035
-For compatibility, they are still defined for external C<XS> code. Only
-extensions defining C<PERL_CORE> must be updated now.
+=item *
-=back
+L<CPAN::Meta> has been upgraded from version 2.110440 to version 2.110930
-=head2 Other Internal Changes
+=item *
-=head3 Stack unwinding
+L<CPANPLUS> has been upgraded from version 0.9103 to version 0.9105
-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.
+Now understands specifying modules to install in the format 'Module/Type.pm'
-=head3 Scope stack entries
+=item *
-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.
+L<CPANPLUS::Dist::Build> has been upgraded from version 0.54 to version 0.56
-=head3 Memory allocation for pointer tables
+=item *
-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.
+L<Data::Dumper> has been upgraded from version 2.128 to 2.131.
-=head3 C<UNDERBAR>
+=item *
-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.
+L<DB_File> has been upgraded from version 1.821 to version 1.822
-=head3 String comparison routines renamed
+Warnings are now in sync with perl's
-The ibcmp_* functions have been renamed and are now called foldEQ,
-foldEQ_locale and foldEQ_utf8. The old names are still available as
-macros.
+=item *
-=head3 C<chop> and C<chomp> implementations merged
+L<Digest::SHA> has been upgraded from version 5.61 to version 5.62
-The opcode bodies for C<chop> and C<chomp> and for C<schop> and C<schomp>
-have been merged. The implementation functions C<Perl_do_chop()> and
-C<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).
+No longer loads L<MIME::Base64> as this was unnecessary.
-=head1 Selected Bug Fixes
+=item *
-=head2 I/O
+L<Devel::Peek> has been upgraded from version 1.07 to 1.08.
-=over 4
+Its C<fill_mstats> function no longer refuses to write to copy-on-write
+scalars.
=item *
-Perl no longer produces this warning:
+L<Encode> has been upgraded from version 2.42 to version 2.43
- $ perl -we 'open my $f, ">", \my $x; binmode $f, "scalar"'
- Use of uninitialized value in binmode at -e line 1.
+Missing aliases added, a deep recursion error fixed and various
+documentation updates.
=item *
-Opening a glob reference via C<< open $fh, "E<gt>", \*glob >> will no longer
-cause 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].
+L<ExtUtils::CBuilder> updated from version 0.280203 to 0.280204. The new version
+append CFLAGS and LDFLAGS to their Config.pm counterparts.
=item *
-PerlIO no longer crashes when called recursively, e.g., from a signal
-handler. Now it just leaks memory [perl #75556].
+L<Filter::Util::Call> has been upgraded from version 1.08 to version 1.39
+
+C<decrypt> fixed to work with v5.14.0
=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 was
-always meant to be the case).
+L<Filter::Simple> updated from version 0.85 to 0.87
=item *
-There have been several fixes to PerlIO layers:
+L<FindBin> updated from version 1.50 to 1.51.
-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, to avoid unexpected
-results [perl #38456].
+It no longer returns a wrong result if a script of the same name as the
+current one exists in the path and is executable.
-Opening a file in C<:raw> mode now does what it advertises to do (first
-open the file, then 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:
+=item *
- open FH, '>:pop:perlio', 'some.file' or die $!;
+L<JSON::PP> has been upgraded from version 2.27105 to version 2.27200
-Would throw an error: "Invalid argument". This has been fixed in this
-release [perl #82484].
+Fixed C<incr_parse> decoding string more correctly.
-=back
+=item *
-=head2 Regular Expression Bug Fixes
+L<I18N::LangTags> has been upgraded from version 0.35_01 to version 0.36.
-=over
+Fix broken URLs for RFCs.
=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 *
+L<IPC::Open3> has been upgraded from version 1.10 to version 1.11.
-The trie runtime code should no longer allocate massive amounts of memory,
-fixing #74484.
+=over 4
=item *
-Syntax errors in C<< (?{...}) >> blocks no longer cause panic messages
-[perl #2353].
+Fixes a bug which prevented use of open3 on Windows when *STDIN, *STDOUT or
+*STDERR had been localized.
=item *
-A pattern like C<(?:(o){2})?> no longer causes a "panic" error
-[perl #39233].
+Fixes a bug which prevented duplicating numeric file descriptors on Windows.
-=item *
-
-A fatal error in regular expressions containing C<(.*?)> when processing
-UTF-8 data has been fixed [perl #75680] (5.12.2).
+=back
=item *
-An erroneous regular expression engine optimisation that caused regex verbs like
-C<*COMMIT> sometimes to be ignored has been removed.
+L<Math::BigFloat> has been upgraded from version 1.993 to 1.994.
+
+The C<numify> method has been corrected to return a normalised Perl number
+(the result of C<0 + $thing>), instead of a string [rt.cpan.org #66732].
=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.
+L<Math::BigInt> has been upgraded from version 1.994 to 1.995.
-=item *
+It provides a new C<bsgn> method that complements the C<babs> method.
-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].
+It fixes the internal C<objectify> function's handling of "foreign objects"
+so they are converted to the appropriate class (Math::BigInt or
+Math::BigFloat).
=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].
+L<Math::Complex> has been upgraded from version 1.56 to version 1.57.
+
+Correct copy constructor usage.
+Fix polarwise formatting with numeric format specifier.
+More stable C<great_circle_direction> algorithm.
=item *
-Matching a Unicode character against an alternation containing characters
-that happened to match continuation bytes in the former's UTF8
-representation (C<qq{\x{30ab}} =~ /\xab|\xa9/>) would cause erroneous
-warnings [perl #70998].
+L<Module::CoreList> has been upgraded from version 2.49 to 2.50.
+
+Updated for v5.12.4.
=item *
-The trie optimisation was not taking empty groups into account, preventing
-'foo' from matching C</\A(?:(?:)foo|bar|zot)\z/> [perl #78356].
+L<mro> has been updated to remove two broken URLs in the documentation.
=item *
-A pattern containing a C<+> inside a lookahead would sometimes cause an
-incorrect match failure in a global match (e.g., C</(?=(\S+))/g>)
-[perl #68564].
+L<Object::Accessor> has been upgraded from version 0.38 to version 0.42
+
+Eliminated use of C<exists> on array elements which has been deprecated.
=item *
-A regular expression optimisation would sometimes cause a match with a
-C<{n,m}> quantifier to fail when it should match [perl #79152].
+L<ODBM_File> has been upgraded from version 1.10 to version 1.11.
+
+The XS code is now compiled with C<PERL_NO_GET_CONTEXT>, which will aid
+performance under ithreads.
=item *
-Case insensitive matching in regular expressions compiled under C<use
-locale> now works much more sanely when the pattern or
-target string is encoded internally 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.
+L<PerlIO::encoding> has been upgraded from version 0.14 to 0.15
=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].
+L<PerlIO::scalar> has been upgraded from version 0.11 to 0.12.
-=item *
+It fixes a problem with C<< open my $fh, ">", \$scalar >> not working if
+C<$scalar> is a copy-on-write scalar.
-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].
+It also fixes a hang that occurs with C<readline> or C<< <$fh> >> if a
+typeglob has been assigned to $scalar [RT #92258].
-=back
+=item *
-=head2 Syntax/Parsing Bugs
+L<Pod::Perldoc> has been upgraded from version 3.15_03 to 3.15_05.
-=over
+It corrects the search paths on VMS [RT #90640].
=item *
-C<when(scalar){...}> no longer crashes, but produces a syntax error
-[perl #74114] (5.12.1).
+L<Storable> has been upgraded from version 2.27 to version 2.28.
+
+It no longer turns copy-on-write scalars into read-only scalars when
+freezing and thawing.
=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).
+L<Sys::Syslog> has been upgraded from version 0.27 to version 0.29
+
+Large number of Request Tickets resolved.
=item *
-The C<no 5.13.2;> form of C<no> no longer tries to turn on features or
-pragmata (i.e., strict) [perl #70075] (5.12.2).
+L<Time::HiRes> has been upgraded from version 1.9721_01 to version 1.9722.
+
+Portability fix, and avoiding some compiler warnings.
=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].
+L<Unicode::Collate> has been upgraded from version 0.73 to version 0.76
+
+Updated to CLDR 1.9.1
=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).
+L<Unicode::Normalize> has been upgraded from version 1.10 to version 1.12
+
+Fixes for the removal of C<unicore/CompositionExclusions.txt> from core.
=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 only be in strict
-mode [perl #81750].
+L<XSLoader> has been upgraded from version 0.13 to version 0.15
-=item *
+Integrated changes from bleadperl
-Constant-folding used to cause
+=item *
- $text =~ ( 1 ? /phoo/ : /bear/)
+L<charnames> can now be invoked with a new option, C<:loose>,
+which is like the existing C<:full> option, but enables Unicode loose
+name matching. This means that instead of
+having to get the name of the code point or sequence you want exactly right,
+you can fudge things somewhat. This is especially useful when
+you don't remember if the official Unicode name uses hyphens or
+blanks between words. Details are in L<charnames/LOOSE MATCHES>.
-to turn into
+XXX
- $text =~ /phoo/
+=back
-at compile time. Now it correctly matches against C<$_> [perl #20444].
+=head2 Removed Modules and Pragmata
-=item *
+As promised in Perl 5.14.0's release notes, the following modules have
+been removed from the core distribution, and if needed should be installed
+from CPAN instead.
-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].
+=over
=item *
-String evals no longer fail after 2 billion scopes have been
-compiled [perl #83364].
+C<Devel::DProf> has been removed from the Perl core. Prior version was 20110228.00.
=item *
-The parser no longer hangs when encountering certain Unicode characters,
-such as U+387 [perl #74022].
+C<Shell> has been removed from the Perl core. Prior version was 0.72_01.
-=item *
+=back
-Several contexts no longer allow a Unicode character to begin a word
-that should never begin words, for an example an accent that must follow
-another character previously could precede all other characters.
+=head1 Documentation
-=item *
+XXX Changes to files in F<pod/> go here. Consider grouping entries by
+file and be sure to link to the appropriate page, e.g. L<perlfunc>.
-Defining a constant with the same name as one of perl's special blocks
-(e.g., INIT) stopped working in 5.12.0, but has now been fixed
-[perl #78634].
+=head2 New Documentation
-=item *
+XXX Changes which create B<new> files in F<pod/> go here.
-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].
+=head3 L<XXX>
-=item *
+XXX Description of the purpose of the new file here
+
+=head2 Changes to Existing Documentation
-A closure containing an C<if> statement followed by a constant or variable
-is no longer treated as a constant [perl #63540].
+XXX Changes which significantly change existing files in F<pod/> go here.
+However, any changes to F<pod/perldiag.pod> should go in the L</Diagnostics>
+section.
-=item *
+=head3 L<perlfork>
-C<state> can now be used with attributes. It used to mean the same thing as
-C<my> if attributes were present [perl #68658].
+=over
=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<E<gt>> expression, but the operand
-of the C<@>) [perl #72090].
+Added portability caveats related to using kill on forked process.
-=item *
+=back
-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:
+=head3 L<perlfunc>
- *d = *a; print $d[0];
- undef *d; print $d[0];
+=over
=item *
-The C<-C> command line option, when used on the shebang line, can now be
-followed by other options [perl #72434].
+C<given>, C<when> and C<default> are now listed in L<perlfunc> (5.14.1).
=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.
+The examples for the C<select> function no longer use strings for file
+handles.
=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 @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:
+=head3 L<perlguts>
=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]
+Some of the function descriptions in L<perlguts> were confusing, as it was
+not clear whether they referred to the function above or below the
+description. This has been clarified [RT #91790].
-=item Deleting packages by deleting their containing stash elements
+=back
-=item Undefining the glob containing a package (C<undef *Foo::>)
+=head3 L<perllol>
-=item Undefining an ISA glob (C<undef *Foo::ISA>)
+=over
-=item Deleting an ISA stash element (C<delete $Foo::{ISA}>)
+=item *
-=item Sharing @ISA arrays between classes (via C<*Foo::ISA = \@Bar::ISA> or
-C<*Foo::ISA = *Bar::ISA>) [perl #77238]
+L<perllol> has been expanded with examples using the new C<push $scalar>
+syntax introduced in Perl 5.14.0 (5.14.1).
=back
-C<undef *Foo::ISA> would even stop a new C<@Foo::ISA> array from updating
-caches.
-
-=item *
+=head3 L<perlmod>
-Typeglob assignments would crash if the glob's stash no longer existed, so
-long as the glob assigned to was named 'ISA' or the glob on either side of
-the assignment contained a subroutine.
+=over
=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].
+L<perlmod> now states explicitly that some types of explicit symbol table
+manipulation are not supported. This codifies what was effectively already
+the case [RT #78074].
=back
-In addition, various other bugs related to typeglobs and stashes have been
-fixed:
+=head3 L<perlop>
-=over
+=over 4
=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 (e.g.
-<%FOO:: = ()>), and complex typeglob or code reference aliasing, will no
-longer crash the interpreter.
+The explanation of bitwise operators has been expanded to explain how they
+work on Unicode strings (5.14.1).
=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].
+The section on the triple-dot or yada-yada operator has been moved up, as
+it used to separate two closely related sections about the comma operator
+(5.14.1).
=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;
- }
+More examples for C<m//g> have been added (5.14.1).
=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:
+The C<<< <<\FOO >>> here-doc syntax has been documented (5.14.1).
- 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].
+=back
-=item *
+=head3 L<perlpodstyle>
-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.
+=over 4
=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:
+The tips on which formatting codes to use have been corrected and greatly
+expanded.
- local *@;
- eval { die bless [] }; # puts an object in $@
- sub DESTROY {
- local $@; # boom
- }
+=item *
-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.
+There are now a couple of example one-liners for previewing POD files after
+they have been edited.
=back
-=head2 Unicode
+=head3 L<perlre>
=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].
+The C<(*COMMIT)> directive is now listed in the right section
+(L<Verbs without an argument|perlre/Verbs without an argument>).
-There are two known exceptions:
-
-=over
+=back
-=item 1
+=head3 L<perlrun>
-The now-deprecated user-defined case changing
-functions require utf8-encoded strings to function. The CPAN module
-L<Unicode::Casing> has been written to replace this feature, without its
-drawacks, and the feature is scheduled to be removed in 5.16
+=over
-=item 2
+=item *
-C<quotemeta> (and its in-line equivalent C<\Q>) also can give different
-results if a string is encoded in UTF-8 or not. See
-L<perlunicode/The "Unicode Bug">.
+L<perlrun> has undergone a significant clean-up. Most notably, the
+B<-0x...> form of the B<-0> flag has been clarified, and the final section
+on environment variables has been corrected and expanded (5.14.1).
=back
-=item *
+=head3 L<perlvar>
-The handling of Unicode non-character code points has changed.
-Previously they were mostly considered illegal, except that only one of
-the 66 of them was known about in places. The Unicode standard
-considers them legal, but forbids the "open interchange" of them.
-This is part of the change to allow the internal use of any code point
-(see L</Core Enhancements>). Together, these changes resolve
-[perl #38722], [perl #51918], [perl #51936], [perl #63446].
+=over
=item *
-Case-insensitive C<"/i"> regular expression matching of Unicode
-characters which match multiple characters now works much more as
-intended. For example
-
- "\N{LATIN SMALL LIGATURE FFI}" =~ /ffi/ui
+The documentation for L<$!|perlvar/$!> has been corrected and clarified.
+It used to state that $! could be C<undef>, which is not the case. It was
+also unclear as to whether system calls set C's C<errno> or Perl's C<$!>
+[RT #91614].
-and
+=back
- "ffi" =~ /\N{LATIN SMALL LIGATURE FFI}/ui
+=head3 L<POSIX>
-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
+=over
- "\N{LATIN SMALL LIGATURE FFI}" =~ /(f)(f)i/ui
+=item *
-or
+The invocation documentation for C<WIFEXITED>, C<WEXITSTATUS>,
+C<WIFSIGNALED>, C<WTERMSIG>, C<WIFSTOPPED>, and C<WSTOPSIG> has been
+corrected (5.14.1).
- "\N{LATIN SMALL LIGATURE FFI}" =~ /ffi*/ui
+=back
-or
+=head1 Diagnostics
- "\N{LATIN SMALL LIGATURE FFI}" =~ /[a-f][f-m][g-z]/ui
+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>.
-None of these match.
+XXX New or changed warnings emitted by the core's C<C> code go here. Also
+include any changes in L<perldiag> that reconcile it to the C<C> code.
-Also, this matching doesn't fully conform to the current Unicode
-standard, which asks that the matching be made upon the NFD
-(Normalization Form .ecomposed) of the text. However, as of this
-writing, March 2010, the Unicode standard is currently in flux about
-what they will recommend doing with regard to such cases. It may be
-that they will throw out the whole concept of multi-character matches.
-[perl #71736].
+[ Within each section, list entries as a =item entry ]
-=item *
+=head2 New Diagnostics
-Naming a deprecated character in \N{...} no longer leaks memory.
+XXX Newly added diagnostic messages go here
-=item *
+=head3 New Warnings
-We fixed a bug that could cause \N{} constructs followed by a single . to
-be parsed incorrectly [perl #74978] (5.12.1).
+=over 4
-=item *
+=item L<Useless assignment to a temporary|perldiag/"Useless assignment to a temporary">
-C<chop> now correctly handles characters above "\x{7fffffff}"
-[perl #73246].
+Assigning to a temporary returned from an XS lvalue subroutine now produces a
+warning [RT #31946].
-=item *
+=back
-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].
+=head2 Changes to Existing Diagnostics
-=item *
+XXX Changes (i.e. rewording) of diagnostic messages go here
-C<warn()> and C<die()> now respect utf8-encoded scalars [perl #45549].
+=over 4
=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 produce a 'panic'
-error message, too [perl #77692].
+XXX
=back
-=head2 Ties, Overloading and Other Magic
-
-=over
-
-=item *
+=head1 Utility Changes
-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].
+XXX Changes to installed programs such as F<perlbug> and F<xsubpp> go
+here. Most of these are built within the directories F<utils> and F<x2p>.
-=item *
+[ List utility changes as a =head3 entry for each utility and =item
+entries for each change
+Use L<XXX> with program names to get proper documentation linking. ]
-Various cases of magic (e.g., tie methods) being called on tied variables
-too many or too few times have been fixed:
+=head3 L<XXX>
-=over
+=over 4
=item *
-FETCH is no longer called on tied variables in void context.
+XXX
-=item *
-
-C<$tied-E<gt>()> did not always call FETCH [perl #8438].
+=back
-=item *
+=head1 Configuration and Compilation
-Filetest operators and C<y///> and C<tr///> were calling FETCH too
-many times.
+XXX Changes to F<Configure>, F<installperl>, F<installman>, and analogous tools
+go here. Any other changes to the Perl build process should be listed here.
+However, any platform-specific changes should be listed in the
+L</Platform Support> section, instead.
-=item *
+[ List changes as a =item entry ].
-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].
+=over 4
=item *
-Dereference operators used to ignore magic if the argument was a
-reference already (e.g., from a previous FETCH) [perl #72144].
+F<regexp.h> has been modified for compatibility with GCC's B<-Werror>
+option, as used by some projects that include perl's header files (5.14.1).
=item *
-C<splice> now calls set-magic (so changes made
-by C<splice @ISA> are respected by method calls) [perl #78400].
+USE_LOCALE{,_COLLATE,_CTYPE,_NUMERIC} have been added the output of perl -V
+as they have affect the behaviour of the interpreter binary (albeit only
+in a small area).
=item *
-In-memory files created by C<open $fh, 'E<gt>' \$buffer> were not calling
-FETCH/STORE at all [perl #43789] (5.12.2).
+The code and tests for L<IPC::Open2> have been moved from F<ext/IPC-Open2>
+into F<ext/IPC-Open3>, as C<IPC::Open2::open2()> is implemented as a thin
+wrapper around C<IPC::Open3::_open3()>, and hence is very tightly coupled to
+it.
=back
-=item *
+=head1 Testing
-String C<eval> now detects taintedness of overloaded or tied
-arguments [perl #75716].
+XXX Any significant changes to the testing of a freshly built perl should be
+listed here. Changes which create B<new> files in F<t/> go here as do any
+large changes to the testing harness (e.g. when parallel testing was added).
+Changes to existing files in F<t/> aren't worth summarising, although the bugs
+that they represent may be covered elsewhere.
-=item *
+[ List each test improvement as a =item entry ]
-String C<eval> and regular expression matches against objects with string
-overloading no longer cause memory corruption or crashes [perl 77084].
+=over 4
=item *
-L<readline|perlfunc/"readline EXPR"> now honors C<< <> >> overloading on tied
-arguments.
+XXX
-=item *
+=back
-C<< E<lt>exprE<gt> >> always respects overloading now if the expression is
-overloaded.
+=head1 Platform Support
-Due to the way that 'E<lt>E<gt> as glob' was parsed differently from
-'E<lt>E<gt> as filehandle' from 5.6 onwards, something like C<< E<lt>$foo[0]E<gt> >> did
-not handle overloading, even if C<$foo[0]> was an overloaded object. This
-was contrary to the documentation for overload, and meant that C<< E<lt>E<gt> >>
-could not be used as a general overloaded iterator operator.
+XXX Any changes to platform support should be listed in the sections below.
-=item *
+[ Within the sections, list each platform as a =item entry with specific
+changes as paragraphs below it. ]
-The fallback behaviour of overloading on binary operators was asymmetric
-[perl #71286].
+=head2 New Platforms
-=item *
+XXX List any platforms that this version of perl compiles on, that previous
+versions did not. These will either be enabled by new files in the F<hints/>
+directories, or new subdirectories and F<README> files at the top level of the
+source tree.
-Magic applied to variables in the main package no longer affects other packages.
-See L</Magic variables outside the main package> above [perl #76138].
+=over 4
-=item *
+=item GNU/Hurd
-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].
+=over
=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 *
+No longer overrides possible extra $ccflags values given to Configure
+on GNU/Hurd. C.f. Bug-Debian: http://bugs.debian.org/587901
-Fixed a regression of kill() when a match variable is used for the
-process ID to kill [perl #75812].
+=back
-=item *
+=item Mac OS X
-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.
+Clarified apple developer tools requirements in README.macosx
-=item *
+=item MSWin32
-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].
+Supplied F<makefile.mk> patched to support gcc-4.x.x and README.win32
+updated accordingly. [RT #91354]
-=item *
+=item Solaris
-utf8::is_utf8 now respects get-magic (e.g. $1) (5.12.1).
+Updated the list of required packages for building perl to reflect Solaris 9
+and 10 in README.solaris [RT #90850]
=back
-=head2 The Debugger
+=head2 Discontinued Platforms
-=over
+XXX List any platforms that this version of perl no longer compiles on.
-=item *
+=over 4
-The Perl debugger now also works in taint mode [perl #76872].
+=item XXX-some-platform
-=item *
+XXX
-Subroutine redefinition works once more in the debugger [perl #48332].
+=back
-=item *
+=head2 Platform-Specific Notes
-When C<-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 what order things happened to be arranged
-in memory [perl #71806].
+XXX List any changes for specific platforms. This could include configuration
+and compilation changes or changes in portability/compatibility. However,
+changes within modules for platforms should generally be listed in the
+L</Modules and Pragmata> section.
-=item *
+=head3 Ubuntu Linux
-A possible memory leak when using L<caller()|perlfunc/"caller EXPR"> to set
-C<@DB::args> has been fixed (5.12.2).
+=over 4
=item *
-Perl no longer stomps on $DB::single, $DB::trace and $DB::signal if they
-already have values when $^P is assigned to [perl #72422].
+The L<ODBM_File> installation process has been updated with the new library
+paths on Ubuntu natty [RT #90106].
=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].
+I<h2ph> now gets the include paths from gcc correctly. This stopped
+working when Ubuntu switched to a "multiarch" setup [RT #90122].
=back
-=head2 Threads
+=head1 Internal Changes
+
+XXX Changes which affect the interface available to C<XS> code go here.
+Other significant internal changes for future core maintainers should
+be noted as well.
-=over
+=over 4
=item *
-Perl no longer accidentally clones lexicals in scope within active stack
-frames in the parent when creating a child thread [perl #73086].
+When empting a hash of its elements (e.g. via undef(%h), or %h=()), HvARRAY
+field is no longer temporarily zeroed. Any destructors called on the freed
+elements see the remaining elements. Thus, %h=() becomes more like C<delete
+$h{$_} for keys %h>.
=item *
-Several memory leaks in cloning and freeing threaded Perl interpreters have been
-fixed [perl #77352].
+The compiled representation of formats is now stored via the mg_ptr of
+their PERL_MAGIC_fm. Previously it was stored in the string buffer,
+beyond SvLEN(), the regular end of the string. SvCOMPILED() and
+SvCOMPILED_{on,off}() now exist solely for compatibility for XS code.
+The first is always 0, the other two now no-ops.
=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 systems that have a C<fchdir>
-function. On other systems, new threads simply do not inherit directory
-handles from their parent threads [perl #75154].
+Boyer-Moore compiled scalars are now PVMGs, and the Boyer-Moore tables are now
+stored via the mg_ptr of their PERL_MAGIC_bm. Previously they were PVGVs, with
+the tables stored in the string buffer, beyond SvLEN(). This eliminates the
+last place where the core stores data beyond SvLEN().
=item *
-The typeglob C<*,>, which holds the scalar variable C<$,> (output field
-separator), had the wrong reference count in child threads.
+C<pos> in lvalue context now returns a PVMG instead of a PVLV, storing the
+target SV in C<mg_obj>, instead of C<LvTARG()>.
=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.
+Simplified logic in C<Perl_sv_magic()> introduces a small change of
+behaviour for error cases involving unknown magic types. Previously, if
+C<Perl_sv_magic()> was passed a magic type unknown to it, it would
-=item *
+=over
-Perl now does a timely cleanup of SVs that are cloned into a new thread but
-then discovered to be orphaned (i.e., their owners are I<not> cloned). This
-eliminates several "scalars leaked" warnings when joining threads.
+=item 1.
-=back
+Croak "Modification of a read-only value attempted" if read only
-=head2 Scoping and Subroutines
+=item 2.
-=over
+Return without error if the SV happened to already have this magic
-=item *
+=item 3.
-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).
+otherwise croak "Don't know how to handle magic of type \\%o"
-=item *
+=back
-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].
+Now it will always croak "Don't know how to handle magic of type \\%o", even
+on read only values, or SVs which already have the unknown magic type.
-=item *
+=back
-C<sort> with a ($$)-prototyped comparison routine used to cause the value
-of @_ to leak out of the sort. Taking a reference to @_ within the
-sorting routine could cause a crash [perl #72334].
+=head1 Selected Bug Fixes
-=item *
+XXX Important bug fixes in the core language are summarised here.
+Bug fixes in files in F<ext/> and F<lib/> are best summarised in
+L</Modules and Pragmata>.
-Match variables (e.g., C<$1>) no longer persist between calls to a sort
-subroutine [perl #76026].
+[ List each fix as a =item entry ]
-=item *
+=head2 Regular expressions and character classes
-Iterating with C<foreach> over an array returned by an lvalue sub now works
-[perl #23790].
+=over 4
=item *
-C<$@> is now localised during calls to C<binmode> to prevent action at a
-distance [perl #78844].
+The new (in 5.14.0) regular expression modifier C</a> when repeated like
+C</aa> forbids the characters outside the ASCII range that match
+characters inside that range from matching under C</i>. This did not
+work under some circumstances, all involving alternation, such as:
-=item *
+ "\N{KELVIN SIGN}" =~ /k|foo/iaa;
-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].
+succeeded inappropriately. This is now fixed.
=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
+5.14.0 introduced some memory leaks in regular expression character
+classes such as C<[\w\s]>, which have now been fixed
-=head2 Signals
+=item *
-=over
+An edge case in regular expression matching could potentially loop.
+This happened only under C</i> in bracketed character classes that have
+characters with multi-character folds, and the target string to match
+against includes the first portion of the fold, followed by another
+character that has a multi-character fold that begins with the remaining
+portion of the fold, plus some more.
-=item *
+ "s\N{U+DF}" =~ /[\x{DF}foo]/i
-Within signal handlers, C<$!> is now implicitly localized.
+is one such case. C<\xDF> folds to C<"ss">
=item *
-CHLD signals are no longer unblocked after a signal handler is called if
-they were blocked before by C<POSIX::sigprocmask> [perl #82040].
+A few characters in regular expression pattern matches did not
+match correctly in some circumstances, all involving C</i>. The
+affected characters are:
+COMBINING GREEK YPOGEGRAMMENI,
+GREEK CAPITAL LETTER IOTA,
+GREEK CAPITAL LETTER UPSILON,
+GREEK PROSGEGRAMMENI,
+GREEK SMALL LETTER IOTA WITH DIALYTIKA AND OXIA,
+GREEK SMALL LETTER IOTA WITH DIALYTIKA AND TONOS,
+GREEK SMALL LETTER UPSILON WITH DIALYTIKA AND OXIA,
+GREEK SMALL LETTER UPSILON WITH DIALYTIKA AND TONOS,
+LATIN SMALL LETTER LONG S,
+LATIN SMALL LIGATURE LONG S T,
+and
+LATIN SMALL LIGATURE ST.
=item *
-A signal handler called within a signal handler could cause leaks or
-double-frees. Now fixed. [perl #76248].
+Fixed memory leak regression in regular expression compilation
+under threading
=back
-=head2 Miscellaneous Memory Leaks
+=head2 Formats
=over
=item *
-Several memory leaks when loading XS modules were fixed (5.12.2).
+A number of edge cases have been fixed with formats and C<formline>;
+in particular, where the format itself is potentially variable (such as
+with ties and overloading), and where the format and data differ in their
+encoding. In both these cases, it used to possible for the output to be
+corrupted [RT #91032].
=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.
+C<formline> no longer converts its argument into a string in-place. So
+passing a reference to C<formline> no longer destroys the reference
+[RT #79532].
-=item *
+=back
-The postincrement and postdecrement operators, C<++> and C<-->, used to cause
-leaks when being used on references. This has now been fixed.
+=head2 Copy-on-write scalars
-=item *
+Copy-on-write scalars were introduced in 5.6.0, but most Perl code
+did not encounter them (they were used mostly internally). Perl
+5.10.0 extended them, such that assigning C<__PACKAGE__> or a
+hash key to a scalar would make it copy-on-write. Several parts
+of Perl were not updated to account for them, but have now been fixed.
-Nested C<map> and C<grep> blocks no longer leak memory when processing
-large lists [perl #48004].
+=over
=item *
-C<use I<VERSION>> and C<no I<VERSION>> no longer leak memory [perl #78436]
-[perl #69050].
+C<utf8::decode> had a nasty bug that would modify copy-on-write scalars'
+string buffers in place (i.e., skipping the copy). This could result in
+hashes having two elements with the same key [RT #91834].
=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].
+Lvalue subroutines were not allowing COW scalars to be returned. This was
+fixed for lvalue scalar context in Perl 5.12.3 and 5.14.0, but list context
+was not fixed until this release.
=item *
-C<eval "BEGIN{die}"> no longer leaks memory on non-threaded builds.
-
-=back
-
-=head2 Memory Corruption and Crashes
-
-=over
+Elements of restricted hashes (see the L<fields> pragma) containing
+copy-on-write values couldn't be deleted, nor could such hashes be cleared
+(C<%hash = ()>).
=item *
-glob() no longer crashes when %File::Glob:: is empty and
-CORE::GLOBAL::glob isn't present [perl #75464] (5.12.2).
+Localising a tied variable used to make it read-only if it contained a
+copy-on-write string.
=item *
-readline() has been fixed when interrupted by signals so it no longer
-returns the "same thing" as before or random memory.
+L<Storable>, L<Devel::Peek> and L<PerlIO::scalar> had similar problems.
+See L</Updated Modules and Pragmata>, above.
-=item *
+=back
-When assigning a list with duplicated keys to a hash, the assignment used to
-return garbage and/or freed values:
+=head2 lvalue subroutines
- @a = %h = (list with some duplicate keys);
+There have been various fixes to lvalue subroutines.
-This has now been fixed [perl #31865].
+=over
=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.
+Explicit return now returns the actual argument passed to return, instead
+of copying it [RT #72724] [RT #72706].
-Perl now only frees 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.
+B<Note:> There are still some discrepancies between explicit and implicit
+return, which will hopefully be resolved soon. So the exact behaviour is
+not set in stone yet.
=item *
-The interpreter no longer crashes when freeing deeply-nested arrays of
-arrays. Hashes have not been fixed yet [perl #44225].
+Lvalue subroutines used to enforce lvalue syntax (i.e., whatever can go on
+the left-hand side of C<=>) for the last statement and the arguments to
+return. Since lvalue subroutines are not always called in lvalue context,
+this restriction has been lifted.
=item *
-Concatenating long strings under C<use encoding> no longer causes perl to
-crash [perl #78674].
+Lvalue subroutines are less restrictive as to what values can be returned.
+It used to croak on values returned by C<shift> and C<delete> and from
+other subroutines, but no longer does so [RT #71172].
=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].
+Empty lvalue subroutines (C<sub :lvalue {}>) used to return C<@_> in list
+context. In fact, all subroutines used to, but regular subs were fixed in
+Perl 5.8.2. Now lvalue subroutines have been likewise fixed.
=item *
-The C<recv> function could crash when called with the MSG_TRUNC flag
-[perl #75082].
+Lvalue subroutines used to copy their return values in rvalue context. Not
+only was this a waste of CPU cycles, but it also caused bugs. A C<($)>
+prototype would cause an lvalue sub to copy its return value [RT #51408],
+and C<while(lvalue_sub() =~ m/.../g) { ... }> would loop endlessly
+[RT #78680].
=item *
-C<formline> no longer crashes when passed a tainted format picture. It also
-taints C<$^A> now if its arguments are tainted [perl #79138].
+Autovivification now works on values returned from lvalue subroutines
+[RT #7946].
=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 stat'ing the _ filehandle.
-This is indicated by OPf_KIDS (as checked in ck_ftst) [perl #74542]
-(5.12.1).
+When called in pass-by-reference context (e.g., subroutine arguments or a list
+passed to C<for>), an lvalue subroutine returning arrays or hashes used to bind
+the arrays (or hashes) to scalar variables--something that is not supposed to
+happen. This could result in "Bizarre copy of ARRAY" errors or C<print>
+ignoring its arguments. It also made nonsensical code like C<@{\$_}> "work".
+This was fixed in 5.14.0 if an array were the first thing returned from the
+subroutine (but not for C<$scalar, @array> or hashes being returned). Now a
+more general fix has been applied [RT #23790].
=item *
-C<unpack()> now handles scalar context correctly for C<%32H> and C<%32u>,
-fixing a potential crash. C<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).
+Assignment to C<keys> returned from an lvalue sub used not to work, but now
+it does.
=back
-=head2 Fixes to Various Perl Operators
+=head2 Fixes related to hashes
=over
=item *
-The C<&> C<|> C<^> bitwise operators no longer coerce read-only arguments
-[perl #20661].
-
-=item *
-
-Stringifying a scalar containing -0.0 no longer has the affect 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].
+A bug has been fixed that would cause a "Use of freed value in iteration"
+error if the next two hash elements that would be iterated over are
+deleted [RT #85026].
=item *
-C<sprintf> was ignoring locales when called with constant arguments
-[perl #78632].
+Freeing deeply nested hashes no longer crashes [RT #44225].
=item *
-Combining the vector (%v) flag and dynamic precision would
-cause sprintf to confuse the order of its arguments, making it treat the
-string as the precision and vice versa [perl #83194].
+Deleting the current hash iterator (the hash element that would be returend
+by the next call to C<each>) in void context used not to free it. The hash
+would continue to reference it until the next iteration. This has been
+fixed [RT #85026].
=back
-=head2 Bugs Relating to the C API
+=head2 Other notable fixes
=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).
+Passing the same constant subroutine to both C<index> and C<formline> no
+longer causes one or the other to fail [RT #89218].
=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].
+List assignment to lexical variables declared with attributes in the same
+statement (C<my ($x,@y) : blimp = (72,94)>) stopped working in Perl 5.8.0.
+It has now been fixed.
=item *
-The XS multicall API no longer causes subroutines to lose reference counts
-if called via the multicall interface from within those very subroutines.
-This affects modules like List::Util. Calling one of its functions with an
-active subroutine as the first argument could cause a crash [perl #78070].
+Perl 5.10.0 introduced some faulty logic that made "U*" in the middle of
+a pack template equivalent to "U0" if the input string was empty. This has
+been fixed [RT #90160].
=item *
-The C<SvPVbyte> function available to XS modules now calls magic before
-downgrading the SV, to avoid warnings about wide characters [perl #72398].
+Destructors on objects were not called during global destruction on objects
+that were not referenced by any scalars. This could happen if an array
+element were blessed (e.g., C<bless \$a[0]>) or if a closure referenced a
+blessed variable (C<bless \my @a; sub foo { @a }>).
-=item *
+Now there is an extra pass during global destruction to fire destructors on
+any objects that might be left after the usual passes that check for
+objects referenced by scalars [RT #36347].
-The ref types in the typemap for XS bindings now support magical variables
-[perl #72684].
+This bug fix was added in Perl 5.13.9, but caused problems with some CPAN
+modules that were relying on the bug. Since it was so close to Perl
+5.14.0, the fix was reverted in 5.13.10, to allow more time for the modules
+to adapt. Hopefully they will be fixed soon (see L</Known Problems>,
+below).
=item *
-C<sv_catsv_flags> no longer calls C<mg_get> on its second argument (the
-source string) if the flags passed to it do not include SV_GMAGIC. So it
-now matches the documentation.
+C<given> was not calling set-magic on the implicit lexical C<$_> that it
+uses. This meant, for example, that C<pos> would be remembered from one
+execution of the same C<given> block to the next, even if the input were a
+different variable [RT #84526].
=item *
-C<my_strftime> no longer leaks memory. This fixes a memory leak in
-C<POSIX::strftime> [perl #73520].
+The "R" command for restarting a debugger session has been fixed to work on
+Windows, or any other system lacking a C<POSIX::_SC_OPEN_MAX> constant
+[RT #87740].
=item *
-XSUB.h now correctly redefines fgets under PERL_IMPLICIT_SYS [perl #55049]
-(5.12.1).
+Fixed a case where it was possible that a freed buffer may have been read
+from when parsing a here document [RT #90128].
=item *
-XS code using C<fputc()> or C<fputs()>: on Windows could cause an error
-due to their arguments being swapped [perl #72704] (5.12.1).
+The C<study> function could become confused if fed a string longer than
+2**31 characters. Now it simply skips such strings.
=item *
-A possible segfault in the C<T_PRTOBJ> default typemap has been fixed
-(5.12.2).
+C<each(I<ARRAY>)> is now wrapped in C<defined(...)>, like C<each(I<HASH>)>,
+inside a C<when> condition [RT #90888].
=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).
+In @INC filters (subroutines returned by subroutines in @INC), $_ used to
+misbehave: If returned from a subroutine, it would not be copied, but the
+variable itself would be returned; and freeing $_ (e.g., with C<undef *_>)
+would cause perl to crash. This has been fixed [RT #91880].
-=back
+=item *
-=head1 Known Problems
+An ASCII single quote (') in a symbol name is meant to be equivalent to a
+double colon (::) except at the end of the name. It was not equivalent if
+followed by a null character, but now it is [RT #88138].
-XXX Many of these have probably already been solved. There are also
-unresolved BBC articles linked to #77718 that are awaiting CPAN
-releases. These may need to be listed here.
-See also #84444. Enbugger may also need to be listed if there is no new
-release in time (see #82152).
-JJORE/overload-eval-0.08.tar.gz appears to be broken, too. See
-http://www.nntp.perl.org/group/perl.perl5.porters/2010/11/msg165773.html
+=item *
-=over 4
+The abbreviations for four C1 control characters
+C<MW>
+C<PM>,
+C<RI>,
+and
+C<ST>
+were previously unrecognized by C<\N{}>,
+vianame(), and string_vianame().
=item *
-C<List::Util::first> misbehaves in the presence of a lexical C<$_>
-(typically introduced by C<my $_> or implicitly by C<given>). The variable
-which gets set for each iteration is the package variable C<$_>, not the
-lexical C<$_>.
-
-A similar issue may occur in other modules that provide functions which
-take a block as their first argument, like
+Some cases of threads crashing due to memory allocation during cloning have
+been fixed [RT #90006].
- foo { ... $_ ...} list
+=item *
-See also: L<http://rt.perl.org/rt3/Public/Bug/Display.html?id=67694>
+Attempting to C<goto> out of a tied handle method used to cause memory
+corruption or crashes. Now it produces an error message instead
+[RT #8611].
-=item *
+=back
-readline() returns an empty string instead of undef when it is
-interrupted by a signal
+=head2 Additional fixes by ticket number
-=item *
+XXX Prefix these with "\n=item *\n" once the list is final
-Test-Harness was updated from 3.17 to 3.21 for this release. A rewrite
-in how it handles non-Perl tests (in 3.17_01) broke argument passing to
-non-Perl tests with L<prove> (RT #59186), and required that non-Perl
-tests be run as C<prove ./test.sh> instead of C<prove test.sh> These
-issues are being solved upstream, but didn't make it into this release.
-They're expected to be fixed in time for perl v5.13.4. (RT #59457)
+Fixed RT #88822: Test failure t/re_fold_grind.t with bleadperl
+Fixed RT #89896: Locale::Maketext test failure
-=item *
+XXX Comments from FC: I do not think these two are necessary.
-C<version> now prevents object methods from being called as class methods
-(d808b68)
+=head1 Known Problems
-=item *
+XXX Descriptions of platform agnostic bugs we know we can't fix go here. Any
+tests that had to be C<TODO>ed for the release would be noted here, unless
+they were specific to a particular platform (see below).
-The changes in L<substr()|perlfunc/"substr EXPR,OFFSET,LENGTH,REPLACEMENT">
-broke C<HTML::Parser> <= 3.66. A fixed C<HTML::Parser> is available as versions
-3.67 on CPAN.
+This is a list of some significant unfixed bugs, which are regressions
+from either 5.XXX.XXX or 5.XXX.XXX.
-=item *
+[ List each fix as a =item entry ]
-The changes in prototype handling break C<Switch>. A patch has been sent
-upstream and will hopefully appear on CPAN soon.
+=over 4
=item *
-The upgrade to Encode-2.40 has caused some tests in the libwww-perl distribution
-on CPAN to fail. (Specifically, F<base/message-charset.t> tests 33-36 in version
-5.836 of that distribution now fail.)
+The fix for RT #36347 causes test failures for C<Gtk2> and C<Tk> on some
+systems [RT #82542].
=item *
-The upgrade to ExtUtils-MakeMaker-6.57_05 has caused some tests in the
-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.)
+The changes to C<tie> cause test failures for the C<JS> module.
=back
-=head1 Errata
-
-=head2 C<keys>, C<values> and C<each> work on arrays
-
-You can now use the C<keys>, C<values>, C<each> builtin functions on arrays
-(previously you could only use them 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 perldelta.
-
=head1 Obituary
-Randy Kobes, creator of the kobesearch alternative to search.cpan.org and
-contributor/maintainer to several core Perl toolchain modules, passed away
-on September 18, 2010 after a battle with lung cancer. His contributions
-to the Perl community will be missed.
+XXX If any significant core contributor has died, we've added a short obituary
+here.
=head1 Acknowledgements
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
+unarchived mailing list, which includes all the core committers, who are 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 only use this address for
https://perl5.git.perl.org / perl5.git / blobdiff