PERL5140DELTA(1) Perl Programmers Reference Guide PERL5140DELTA(1)

PERL5140DELTA(1) Perl Programmers Reference Guide PERL5140DELTA(1) #

PERL5140DELTA(1) Perl Programmers Reference Guide PERL5140DELTA(1)

NNAAMMEE #

 perl5140delta - what is new for perl v5.14.0

DDEESSCCRRIIPPTTIIOONN #

 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
 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.

NNoottiiccee As described in perlpolicy, the release of Perl 5.14.0 marks the official end of support for Perl 5.10. Users of Perl 5.10 or earlier should consider upgrading to a more recent release of Perl.

CCoorree EEnnhhaanncceemmeennttss UUnniiccooddee _U_n_i_c_o_d_e _V_e_r_s_i_o_n _6_._0 _i_s _n_o_w _s_u_p_p_o_r_t_e_d _(_m_o_s_t_l_y_)

 Perl comes with the Unicode 6.0 data base updated with Corrigendum #8
 <http://www.unicode.org/versions/corrigendum8.html>, with one exception
 noted below.  See <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 "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 "BELL" mean the ASCII "BEL" character, U+0007.  In Perl 5.14,
 "\N{BELL}" continues to mean U+0007, but its use generates a deprecation
 warning message unless such warnings are turned off.  The new name for
 U+0007 in Perl is "ALERT", which corresponds nicely with the existing
 shorthand sequence for it, "\a".  "\N{BEL}" means U+0007, with no warning
 given.  The character at U+1F514 has no name in 5.14, but can be referred
 to by "\N{U+1F514}".  In Perl 5.16, "\N{BELL}" will refer to U+1F514; all
 code that uses "\N{BELL}" should be converted to use "\N{ALERT}",
 "\N{BEL}", or "\a" before upgrading.

 _F_u_l_l _f_u_n_c_t_i_o_n_a_l_i_t_y _f_o_r _"_u_s_e _f_e_a_t_u_r_e _'_u_n_i_c_o_d_e___s_t_r_i_n_g_s_'_"

 This release provides full functionality for "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 "the 'unicode_strings' feature" in feature.
 However, see "Inverted bracketed character classes and multi-character
 folds", below.

 This feature avoids most forms of the "Unicode Bug" (see "The "Unicode
 Bug"" in perlunicode for details).  If there is any possibility that your
 code will process Unicode strings, you are _s_t_r_o_n_g_l_y encouraged to use
 this subpragma to avoid nasty surprises.

 _"_\_N_{_N_A_M_E_}_" _a_n_d _"_c_h_a_r_n_a_m_e_s_" _e_n_h_a_n_c_e_m_e_n_t_s

 •   "\N{_N_A_M_E}" and "charnames::vianame" now know about the abbreviated
     character names listed by Unicode, such as NBSP, SHY, LRO, ZWJ, etc.;
     all customary abbreviations for the C0 and C1 control characters
     (such as ACK, BEL, CAN, etc.); and a few new variants of some C1 full
     names that are in common usage.

 •   Unicode has several _n_a_m_e_d _c_h_a_r_a_c_t_e_r _s_e_q_u_e_n_c_e_s, in which particular
     sequences of code points are given names.  "\N{_N_A_M_E}" now recognizes
     these.

 •   "\N{_N_A_M_E}", "charnames::vianame", and "charnames::viacode" now know
     about every character in Unicode.  In earlier releases of Perl, they
     didn't know about the Hangul syllables nor several CJK
     (Chinese/Japanese/Korean) characters.

 •   It is now possible to override Perl's abbreviations with your own
     custom aliases.

 •   You can now create a custom alias of the ordinal of a character,
     known by "\N{_N_A_M_E}", "charnames::vianame()", and
     "charnames::viacode()".  Previously, aliases had to be to official
     Unicode character names.  This made it impossible to create an alias
     for unnamed code points, such as those reserved for private use.

 •   The new function cchhaarrnnaammeess::::ssttrriinngg__vviiaannaammee(()) is a run-time version of
     "\N{_N_A_M_E}}", returning the string of characters whose Unicode name is
     its parameter.  It can handle Unicode named character sequences,
     whereas the pre-existing cchhaarrnnaammeess::::vviiaannaammee(()) cannot, as the latter
     returns a single code point.

 See charnames for details on all these changes.

 _N_e_w _w_a_r_n_i_n_g_s _c_a_t_e_g_o_r_i_e_s _f_o_r _p_r_o_b_l_e_m_a_t_i_c _(_n_o_n_-_)_U_n_i_c_o_d_e _c_o_d_e _p_o_i_n_t_s_.

 Three new warnings subcategories of "utf8" have been added.  These allow
 you to turn off some "utf8" warnings, while allowing other warnings to
 remain on.  The three categories are: "surrogate" when UTF-16 surrogates
 are encountered; "nonchar" when Unicode non-character code points are
 encountered; and "non_unicode" when code points above the legal Unicode
 maximum of 0x10FFFF are encountered.

 _A_n_y _u_n_s_i_g_n_e_d _v_a_l_u_e _c_a_n _b_e _e_n_c_o_d_e_d _a_s _a _c_h_a_r_a_c_t_e_r

 With this release, Perl is adopting a model that any unsigned value can
 be treated as a code point and encoded internally (as utf8) without
 warnings, not just the code points that are legal in Unicode.  However,
 unless utf8 or the corresponding sub-category (see previous item) of
 lexical warnings have been explicitly turned off, outputting or executing
 a Unicode-defined operation such as upper-casing on such a code point
 generates a warning.  Attempting to input these using strict rules (such
 as with the ":encoding(UTF-8)" layer) will continue to fail.  Prior to
 this release, handling was inconsistent and in places, incorrect.

 Unicode non-characters, some of which previously were erroneously
 considered illegal in places by Perl, contrary to the Unicode Standard,
 are now always legal internally.  Inputting or outputting them works the
 same as with the non-legal Unicode code points, because the Unicode
 Standard says they are (only) illegal for "open interchange".

 _U_n_i_c_o_d_e _d_a_t_a_b_a_s_e _f_i_l_e_s _n_o_t _i_n_s_t_a_l_l_e_d

 The Unicode database files are no longer installed with Perl.  This
 doesn't affect any functionality in Perl and saves significant disk
 space.  If you need these files, you can download them from
 <http://www.unicode.org/Public/zipped/6.0.0/>.

RReegguullaarr EExxpprreessssiioonnss _"_(_?_^_._._._)_" _c_o_n_s_t_r_u_c_t _s_i_g_n_i_f_i_e_s _d_e_f_a_u_l_t _m_o_d_i_f_i_e_r_s

 An ASCII caret "^" immediately following a "(?" in a regular expression
 now means that the subexpression does not inherit surrounding modifiers
 such as "/i", but reverts to the Perl defaults.  Any modifiers following
 the caret override the defaults.

 Stringification of regular expressions now uses this notation.  For
 example, "qr/hlagh/i" would previously be stringified as
 "(?i-xsm:hlagh)", but now it's stringified as "(?^i:hlagh)".

 The main purpose of this change is to allow tests that rely on the
 stringification _n_o_t to have to change whenever new modifiers are added.
 See "Extended Patterns" in perlre.

 This change is likely to break code that compares stringified regular
 expressions with fixed strings containing "?-xism".

 _"_/_d_"_, _"_/_l_"_, _"_/_u_"_, _a_n_d _"_/_a_" _m_o_d_i_f_i_e_r_s

 Four new regular expression modifiers have been added.  These are
 mutually exclusive: one only can be turned on at a time.

 •   The "/l" modifier says to compile the regular expression as if it
     were in the scope of "use locale", even if it is not.

 •   The "/u" modifier says to compile the regular expression as if it
     were in the scope of a "use feature 'unicode_strings'" pragma.

 •   The "/d" (default) modifier is used to override any "use locale" and
     "use feature 'unicode_strings'" pragmas in effect at the time of
     compiling the regular expression.

 •   The "/a" regular expression modifier restricts "\s", "\d" and "\w"
     and the POSIX ("[[:posix:]]") character classes to the ASCII range.
     Their complements and "\b" and "\B" are correspondingly affected.
     Otherwise, "/a" behaves like the "/u" modifier, in that case-
     insensitive matching uses Unicode semantics.

     If the "/a" modifier is repeated, then additionally in case-
     insensitive matching, no ASCII character can match a non-ASCII
     character.  For example,

         "k"     =~ /\N{KELVIN SIGN}/ai
         "\xDF" =~ /ss/ai

     match but

         "k"    =~ /\N{KELVIN SIGN}/aai
         "\xDF" =~ /ss/aai

     do not match.

 See "Modifiers" in perlre for more detail.

 _N_o_n_-_d_e_s_t_r_u_c_t_i_v_e _s_u_b_s_t_i_t_u_t_i_o_n

 The substitution ("s///") and transliteration ("y///") operators now
 support an "/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 "map".  See perlop for more examples.

 _R_e_-_e_n_t_r_a_n_t _r_e_g_u_l_a_r _e_x_p_r_e_s_s_i_o_n _e_n_g_i_n_e

 It is now safe to use regular expressions within "(?{...})" and
 "(??{...})" code blocks inside regular expressions.

 These blocks are still experimental, however, and still have problems
 with lexical ("my") variables and abnormal exiting.

 _"_u_s_e _r_e _'_/_f_l_a_g_s_'_"

 The "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 "'/flags' mode" in re for details.

 _\_o_{_._._._} _f_o_r _o_c_t_a_l_s

 There is a new octal escape sequence, "\o", in doublequote-like contexts.
 This construct allows large octal ordinals beyond the current max of 0777
 to be represented.  It also allows you to specify a character in octal
 which can safely be concatenated with other regex snippets and which
 won't be confused with being a backreference to a regex capture group.
 See "Capture groups" in perlre.

 _A_d_d _"_\_p_{_T_i_t_l_e_c_a_s_e_}_" _a_s _a _s_y_n_o_n_y_m _f_o_r _"_\_p_{_T_i_t_l_e_}_"

 This synonym is added for symmetry with the Unicode property names
 "\p{Uppercase}" and "\p{Lowercase}".

 _R_e_g_u_l_a_r _e_x_p_r_e_s_s_i_o_n _d_e_b_u_g_g_i_n_g _o_u_t_p_u_t _i_m_p_r_o_v_e_m_e_n_t

 Regular expression debugging output (turned on by "use re 'debug'") now
 uses hexadecimal when escaping non-ASCII characters, instead of octal.

 _R_e_t_u_r_n _v_a_l_u_e _o_f _"_d_e_l_e_t_e _$_+_{_._._._}_"

 Custom regular expression engines can now determine the return value of
 "delete" on an entry of "%+" or "%-".

SSyynnttaaccttiiccaall EEnnhhaanncceemmeennttss _A_r_r_a_y _a_n_d _h_a_s_h _c_o_n_t_a_i_n_e_r _f_u_n_c_t_i_o_n_s _a_c_c_e_p_t _r_e_f_e_r_e_n_c_e_s

 WWaarrnniinngg:: This feature is considered experimental, as the exact behaviour
 may change in a future version of Perl.

 All builtin functions that operate directly on array or hash containers
 now also accept unblessed hard references to arrays or hashes:

   |----------------------------+---------------------------|
   | Traditional syntax         | Terse syntax              |
   |----------------------------+---------------------------|
   | push @$arrayref, @stuff    | push $arrayref, @stuff    |
   | unshift @$arrayref, @stuff | unshift $arrayref, @stuff |
   | pop @$arrayref             | pop $arrayref             |
   | shift @$arrayref           | shift $arrayref           |
   | splice @$arrayref, 0, 2    | splice $arrayref, 0, 2    |
   | keys %$hashref             | keys $hashref             |
   | keys @$arrayref            | keys $arrayref            |
   | values %$hashref           | values $hashref           |
   | values @$arrayref          | values $arrayref          |
   | ($k,$v) = each %$hashref   | ($k,$v) = each $hashref   |
   | ($k,$v) = each @$arrayref  | ($k,$v) = each $arrayref  |
   |----------------------------+---------------------------|

 This allows these builtin functions to act on long dereferencing chains
 or on the return value of subroutines without needing to wrap them in
 "@{}" or "%{}":

   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

 _S_i_n_g_l_e _t_e_r_m _p_r_o_t_o_t_y_p_e

 The "+" prototype is a special alternative to "$" that acts like "\[@%]"
 when given a literal array or hash variable, but will otherwise force
 scalar context on the argument.  See "Prototypes" in perlsub.

 _"_p_a_c_k_a_g_e_" _b_l_o_c_k _s_y_n_t_a_x

 A package declaration can now contain a code block, in which case the
 declaration is in scope inside that block only.  So "package Foo { ... }"
 is precisely equivalent to "{ package Foo; ... }".  It also works with a
 version number in the declaration, as in "package Foo 1.2 { ... }", which
 is its most attractive feature.  See perlfunc.

 _S_t_a_t_e_m_e_n_t _l_a_b_e_l_s _c_a_n _a_p_p_e_a_r _i_n _m_o_r_e _p_l_a_c_e_s

 Statement labels can now occur before any type of statement or
 declaration, such as "package".

 _S_t_a_c_k_e_d _l_a_b_e_l_s

 Multiple statement labels can now appear before a single statement.

 _U_p_p_e_r_c_a_s_e _X_/_B _a_l_l_o_w_e_d _i_n _h_e_x_a_d_e_c_i_m_a_l_/_b_i_n_a_r_y _l_i_t_e_r_a_l_s

 Literals may now use either upper case "0X..." or "0B..." prefixes, in
 addition to the already supported "0x..." and "0b..." syntax [perl
 #76296].

 C, Ruby, Python, and PHP already support this syntax, and it makes Perl
 more internally consistent: a round-trip with "eval sprintf "%#X", 0x10"
 now returns 16, just like "eval sprintf "%#x", 0x10".

 _O_v_e_r_r_i_d_a_b_l_e _t_i_e _f_u_n_c_t_i_o_n_s

 "tie", "tied" and "untie" can now be overridden [perl #75902].

EExxcceeppttiioonn HHaannddlliinngg To make them more reliable and consistent, several changes have been made to how “die”, “warn”, and $@ behave.

 •   When an exception is thrown inside an "eval", the exception is no
     longer at risk of being clobbered by destructor code running during
     unwinding.  Previously, the exception was written into $@ early in
     the throwing process, and would be overwritten if "eval" was used
     internally in the destructor for an object that had to be freed while
     exiting from the outer "eval".  Now the exception is written into $@
     last thing before exiting the outer "eval", so the code running
     immediately thereafter can rely on the value in $@ correctly
     corresponding to that "eval".  ($@ is still also set before exiting
     the "eval", for the sake of destructors that rely on this.)

     Likewise, a "local $@" inside an "eval" no longer clobbers any
     exception thrown in its scope.  Previously, the restoration of $@
     upon unwinding would overwrite any exception being thrown.  Now the
     exception gets to the "eval" anyway.  So "local $@" is safe before a
     "die".

     Exceptions thrown from object destructors no longer modify the $@ 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 $@ or
     completely replaced the surrounding $@, depending on whether that
     exception and the surrounding $@ were strings or objects.  Now, an
     exception in this situation is always emitted as a warning, leaving
     the surrounding $@ untouched.  In addition to object destructors,
     this also affects any function call run by XS code using the
     "G_KEEPERR" flag.

 •   Warnings for "warn" can now be objects in the same way as exceptions
     for "die".  If an object-based warning gets the default handling of
     writing to standard error, it is stringified as before with the
     filename and line number appended.  But a $SIG{__WARN__} handler now
     receives an object-based warning as an object, where previously it
     was passed the result of stringifying the object.

OOtthheerr EEnnhhaanncceemmeennttss _A_s_s_i_g_n_m_e_n_t _t_o _$_0 _s_e_t_s _t_h_e _l_e_g_a_c_y _p_r_o_c_e_s_s _n_a_m_e _w_i_t_h _pp_rr_cc_tt_ll_((_)) _o_n _L_i_n_u_x

 On Linux the legacy process name is now set with pprrccttll(2), in addition to
 altering the POSIX name via "argv[0]", as Perl has done since version
 4.000.  Now system utilities that read the legacy process name such as
 _p_s, _t_o_p, and _k_i_l_l_a_l_l recognize the name you set when assigning to $0.
 The string you supply is truncated at 16 bytes; this limitation is
 imposed by Linux.

 _ss_rr_aa_nn_dd_((_)) _n_o_w _r_e_t_u_r_n_s _t_h_e _s_e_e_d

 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
 ssrraanndd(()) and stash the return value for future use.  One example is a test
 program with too many combinations to test comprehensively in the time
 available for each run.  It can test a random subset each time and,
 should there be a failure, log the seed used for that run so this can
 later be used to produce the same results.

 _p_r_i_n_t_f_-_l_i_k_e _f_u_n_c_t_i_o_n_s _u_n_d_e_r_s_t_a_n_d _p_o_s_t_-_1_9_8_0 _s_i_z_e _m_o_d_i_f_i_e_r_s

 Perl's printf and sprintf operators, and Perl's internal printf
 replacement function, now understand the C90 size modifiers "hh"
 ("char"), "z" ("size_t"), and "t" ("ptrdiff_t").  Also, when compiled
 with a C99 compiler, Perl now understands the size modifier "j"
 ("intmax_t") (but this is not portable).

 So, for example, on any modern machine, "sprintf("%hhd", 257)" returns
 "1".

 _N_e_w _g_l_o_b_a_l _v_a_r_i_a_b_l_e _"_$_{_^_G_L_O_B_A_L___P_H_A_S_E_}_"

 A new global variable, "${^GLOBAL_PHASE}", has been added to allow
 introspection of the current phase of the Perl interpreter.  It's
 explained in detail in "${^GLOBAL_PHASE}" in perlvar and in "BEGIN,
 UNITCHECK, CHECK, INIT and END" in perlmod.

 _"_-_d_:_-_f_o_o_" _c_a_l_l_s _"_D_e_v_e_l_:_:_f_o_o_:_:_u_n_i_m_p_o_r_t_"

 The syntax --dd::ffoooo was extended in 5.6.1 to make --dd::ffoooo==bbaarr equivalent to
 --MMDDeevveell::::ffoooo==bbaarr, which expands internally to "use Devel::foo 'bar'".
 Perl now allows prefixing the module name with --, with the same semantics
 as --MM; that is:

 "-d:-foo"
     Equivalent to --MM--DDeevveell::::ffoooo: expands to "no Devel::foo" and calls
     "Devel::foo->unimport()" if that method exists.

 "-d:-foo=bar"
     Equivalent to --MM--DDeevveell::::ffoooo==bbaarr: expands to "no Devel::foo 'bar'",
     and calls "Devel::foo->unimport("bar")" if that method exists.

 This is particularly useful for suppressing the default actions of a
 "Devel::*" module's "import" method whilst still loading it for
 debugging.

 _F_i_l_e_h_a_n_d_l_e _m_e_t_h_o_d _c_a_l_l_s _l_o_a_d _I_O_:_:_F_i_l_e _o_n _d_e_m_a_n_d

 When a method call on a filehandle would die because the method cannot be
 resolved and IO::File has not been loaded, Perl now loads IO::File via
 "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 happens only if method resolution fails, the
 legacy approach of manually loading an 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

 _I_m_p_r_o_v_e_d _I_P_v_6 _s_u_p_p_o_r_t

 The "Socket" module provides new affordances for IPv6, including
 implementations of the "Socket::getaddrinfo()" and
 "Socket::getnameinfo()" functions, along with related constants and a
 handful of new functions.  See Socket.

 _D_T_r_a_c_e _p_r_o_b_e_s _n_o_w _i_n_c_l_u_d_e _p_a_c_k_a_g_e _n_a_m_e

 The "DTrace" probes now include an additional argument, "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

NNeeww CC AAPPIIss See “Internal Changes”.

SSeeccuurriittyy UUsseerr--ddeeffiinneedd rreegguullaarr eexxpprreessssiioonn pprrooppeerrttiieess “User-Defined Character Properties” in perlunicode documented that you can create custom properties by defining subroutines whose names begin with “In” or “Is”. However, Perl did not actually enforce that naming restriction, so “\p{foo::bar}” could call ffoooo::::bbaarr(()) if it existed. The documented convention is now enforced.

 Also, Perl no longer allows tainted regular expressions to invoke a user-
 defined property.  It simply dies instead [perl #82616].

IInnccoommppaattiibbllee CChhaannggeess Perl 5.14.0 is not binary-compatible with any previous stable release.

 In addition to the sections that follow, see "C API Changes".

RReegguullaarr EExxpprreessssiioonnss aanndd SSttrriinngg EEssccaappeess _I_n_v_e_r_t_e_d _b_r_a_c_k_e_t_e_d _c_h_a_r_a_c_t_e_r _c_l_a_s_s_e_s _a_n_d _m_u_l_t_i_-_c_h_a_r_a_c_t_e_r _f_o_l_d_s

 Some characters match a sequence of two or three characters in "/i"
 regular expression matching under Unicode rules.  One example is "LATIN
 SMALL LETTER SHARP S" which matches the sequence "ss".

  'ss' =~ /\A[\N{LATIN SMALL LETTER SHARP S}]\z/i  # Matches

 This, however, can lead to very counter-intuitive results, especially
 when inverted.  Because of this, Perl 5.14 does not use multi-character
 "/i" matching in inverted character classes.

  'ss' =~ /\A[^\N{LATIN SMALL LETTER SHARP S}]+\z/i  # ???

 This should match any sequences of characters that aren't the "SHARP S"
 nor what "SHARP S" matches under "/i".  "s" isn't "SHARP S", but Unicode
 says that "ss" is what "SHARP S" matches under "/i".  So which one
 "wins"? Do you fail the match because the string has "ss" or accept it
 because it has an "s" followed by another "s"?

 Earlier releases of Perl did allow this multi-character matching, but due
 to bugs, it mostly did not work.

 _\_4_0_0_-_\_7_7_7

 In certain circumstances, "\400"-"\777" in regexes have behaved
 differently than they behave in all other doublequote-like contexts.
 Since 5.10.1, Perl has issued a deprecation warning when this happens.
 Now, these literals behave the same in all doublequote-like contexts,
 namely to be equivalent to "\x{100}"-"\x{1FF}", with no deprecation
 warning.

 Use of "\400"-"\777" in the command-line option --00 retain their
 conventional meaning.  They slurp whole input files; previously, this was
 documented only for --00777777.

 Because of various ambiguities, you should use the new "\o{...}"
 construct to represent characters in octal instead.

 _M_o_s_t _"_\_p_{_}_" _p_r_o_p_e_r_t_i_e_s _a_r_e _n_o_w _i_m_m_u_n_e _t_o _c_a_s_e_-_i_n_s_e_n_s_i_t_i_v_e _m_a_t_c_h_i_n_g

 For most Unicode properties, it doesn't make sense to have them match
 differently under "/i" case-insensitive matching.  Doing so can lead to
 unexpected results and potential security holes.  For example

  m/\p{ASCII_Hex_Digit}+/i

 could previously match non-ASCII characters because of the Unicode
 matching rules (although there were several bugs with this).  Now
 matching under "/i" gives the same results as non-"/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 "m/\p{Uppercase}/i" and "m/\p{Lowercase}/i", both of which match the
 same code points as matched by "m/\p{Cased}/i".  Details are in "Unicode
 Properties" in perlrecharclass.

 User-defined property handlers that need to match differently under "/i"
 must be changed to read the new boolean parameter passed to them, which
 is non-zero if case-insensitive matching is in effect and 0 otherwise.
 See "User-Defined Character Properties" in perlunicode.

 _\_p_{_} _i_m_p_l_i_e_s _U_n_i_c_o_d_e _s_e_m_a_n_t_i_c_s

 Specifying a Unicode property in the pattern indicates that the pattern
 is meant for matching according to Unicode rules, the way "\N{_N_A_M_E}"
 does.

 _R_e_g_u_l_a_r _e_x_p_r_e_s_s_i_o_n_s _r_e_t_a_i_n _t_h_e_i_r _l_o_c_a_l_e_n_e_s_s _w_h_e_n _i_n_t_e_r_p_o_l_a_t_e_d

 Regular expressions compiled under "use locale" now retain this when
 interpolated into a new regular expression compiled outside a "use
 locale", and vice-versa.

 Previously, one regular expression interpolated into another inherited
 the localeness of the surrounding regex, losing whatever state it
 originally had.  This is considered a bug fix, but may trip up code that
 has come to rely on the incorrect behaviour.

 _S_t_r_i_n_g_i_f_i_c_a_t_i_o_n _o_f _r_e_g_e_x_e_s _h_a_s _c_h_a_n_g_e_d

 Default regular expression modifiers are now notated using "(?^...)".
 Code relying on the old stringification will fail.  This is so that when
 new modifiers are added, such code won't have to keep changing each time
 this happens, because the stringification will automatically incorporate
 the new modifiers.

 Code that needs to work properly with both old- and new-style regexes can
 avoid the whole issue by using (for perls since 5.9.5; see 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 $modifiers instead of "-xism".

 _R_u_n_-_t_i_m_e _c_o_d_e _b_l_o_c_k_s _i_n _r_e_g_u_l_a_r _e_x_p_r_e_s_s_i_o_n_s _i_n_h_e_r_i_t _p_r_a_g_m_a_t_a

 Code blocks in regular expressions ("(?{...})" and "(??{...})")
 previously did not inherit pragmata (strict, warnings, etc.) if the
 regular expression was compiled at run time as happens in cases like
 these two:

   use re "eval";
   $foo =~ $bar; # when $bar contains (?{...})
   $foo =~ /$bar(?{ $finished = 1 })/;

 This bug has now been fixed, but code that relied on the buggy behaviour
 may need to be fixed to account for the correct behaviour.

SSttaasshheess aanndd PPaacckkaaggee VVaarriiaabblleess _L_o_c_a_l_i_s_e_d _t_i_e_d _h_a_s_h_e_s _a_n_d _a_r_r_a_y_s _a_r_e _n_o _l_o_n_g_e_d _t_i_e_d

 In the following:

     tie @a, ...;
     {
             local @a;
             # here, @a is a now a new, untied array
     }
     # here, @a refers again to the old, tied array

 Earlier versions of Perl incorrectly tied the new local array.  This has
 now been fixed.  This fix could however potentially cause a change in
 behaviour of some code.

 _S_t_a_s_h_e_s _a_r_e _n_o_w _a_l_w_a_y_s _d_e_f_i_n_e_d

 "defined %Foo::" now always returns true, even when no symbols have yet
 been defined in that package.

 This is a side-effect of removing a special-case kludge in the tokeniser,
 added for 5.10.0, to hide side-effects of changes to the internal storage
 of hashes.  The fix drastically reduces hashes' memory overhead.

 Calling defined on a stash has been deprecated since 5.6.0, warned on
 lexicals since 5.6.0, and warned for stashes and other package variables
 since 5.12.0.  "defined %hash" has always exposed an implementation
 detail: emptying a hash by deleting all entries from it does not make
 "defined %hash" false.  Hence "defined %hash" is not valid code to
 determine whether an arbitrary hash is empty.  Instead, use the behaviour
 of an empty %hash always returning false in scalar context.

 _C_l_e_a_r_i_n_g _s_t_a_s_h_e_s

 Stash list assignment "%foo:: = ()" used to make the stash temporarily
 anonymous while it was being emptied.  Consequently, any of its
 subroutines referenced elsewhere would become anonymous,  showing up as
 "(unknown)" in "caller".  They now retain their package names such that
 "caller" returns the original sub name if there is still a reference to
 its typeglob and "foo::__ANON__" otherwise [perl #79208].

 _D_e_r_e_f_e_r_e_n_c_i_n_g _t_y_p_e_g_l_o_b_s

 If you assign a typeglob to a scalar variable:

     $glob = *foo;

 the glob that is copied to $glob is marked with a special flag indicating
 that the glob is just a copy.  This allows subsequent assignments to
 $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: "untie $scalar"
 would not untie the scalar if the last thing assigned to it was a glob
 (because it treated it as "untie *$scalar", which unties a handle).
 Assignment to a glob slot (such as "*$glob = \@some_array") would simply
 assign "\@some_array" to $glob.

 To fix this, the "*{}" operator (including its *foo and *$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.  ("tie", "tied"
 and "untie" have been left as they are for compatibility's sake, but will
 warn.  See "Deprecations".)

 This causes an incompatible change in code that assigns a glob to the
 return value of "*{}" when that operator was passed a glob copy.  Take
 the following code, for instance:

     $glob = *foo;
     *$glob = *bar;

 The *$glob on the second line returns a new immutable glob.  That new
 glob is made an alias to *bar.  Then it is discarded.  So the second
 assignment has no effect.

 See <https://github.com/Perl/perl5/issues/10625> for more detail.

 _M_a_g_i_c _v_a_r_i_a_b_l_e_s _o_u_t_s_i_d_e _t_h_e _m_a_i_n _p_a_c_k_a_g_e

 In previous versions of Perl, magic variables like $!, %SIG, etc. would
 "leak" into other packages.  So %foo::SIG could be used to access
 signals, "${"foo::!"}" (with strict mode off) to access C's "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).

 _l_o_c_a_l_(_$___) _s_t_r_i_p_s _a_l_l _m_a_g_i_c _f_r_o_m _$__

 llooccaall(()) on scalar variables gives them a new value but keeps all their
 magic intact.  This has proven problematic for the default scalar
 variable $_, where perlsub recommends that any subroutine that assigns to
 $_ should first localize it.  This would throw an exception if $_ is
 aliased to a read-only variable, and could in general have various
 unintentional side-effects.

 Therefore, as an exception to the general rule, local($_) will not only
 assign a new value to $_, but also remove all existing magic from it as
 well.

 _P_a_r_s_i_n_g _o_f _p_a_c_k_a_g_e _a_n_d _v_a_r_i_a_b_l_e _n_a_m_e_s

 Parsing the names of packages and package variables has changed: multiple
 adjacent pairs of colons, as in "foo::::bar", are now all treated as
 package separators.

 Regardless of this change, the exact parsing of package separators has
 never been guaranteed and is subject to change in future Perl versions.

CChhaannggeess ttoo SSyynnttaaxx oorr ttoo PPeerrll OOppeerraattoorrss _"_g_i_v_e_n_" _r_e_t_u_r_n _v_a_l_u_e_s

 "given" blocks now return the last evaluated expression, or an empty list
 if the block was exited by "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 "Return value" in perlsyn for details.

 _C_h_a_n_g_e _i_n _p_a_r_s_i_n_g _o_f _c_e_r_t_a_i_n _p_r_o_t_o_t_y_p_e_s

 Functions declared with the following prototypes now behave correctly as
 unary functions:

   *
   \$ \% \@ \* \&
   \[...]
   ;$ ;*
   ;\$ ;\% etc.
   ;\[...]

 Due to this bug fix [perl #75904], functions using the "(*)", "(;$)" and
 "(;*)" 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 "foo($a) < $b", rather than
 "foo($a < $b)".  This happens when one of these operators is used in an
 unparenthesised argument:

   < > <= >= lt gt le ge
   == != <=> eq ne cmp ~~
   &
   | ^
   &&
   || //
   .. ...
   ?:
   = += -= *= etc.
   , =>

 _S_m_a_r_t_-_m_a_t_c_h_i_n_g _a_g_a_i_n_s_t _a_r_r_a_y _s_l_i_c_e_s

 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].

 _N_e_g_a_t_i_o_n _t_r_e_a_t_s _s_t_r_i_n_g_s _d_i_f_f_e_r_e_n_t_l_y _f_r_o_m _b_e_f_o_r_e

 The unary negation operator, "-", now treats strings that look like
 numbers as numbers [perl #57706].

 _N_e_g_a_t_i_v_e _z_e_r_o

 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
 "sprintf("%g", $zero) =~ /^-/" or the Data::Float module on CPAN.

 _"_:_=_" _i_s _n_o_w _a _s_y_n_t_a_x _e_r_r_o_r

 Previously "my $pi := 4" was exactly equivalent to "my $pi : = 4", with
 the ":" being treated as the start of an attribute list, ending before
 the "=".  The use of ":=" to mean ": =" was deprecated in 5.12.0, and is
 now a syntax error.  This allows future use of ":=" as a new token.

 Outside the core's tests for it, we find no Perl 5 code on CPAN using
 this construction, so we believe that this change will have little impact
 on real-world codebases.

 If it is absolutely necessary to have empty attribute lists (for example,
 because of a code generator), simply avoid the error by adding a space
 before the "=".

 _C_h_a_n_g_e _i_n _t_h_e _p_a_r_s_i_n_g _o_f _i_d_e_n_t_i_f_i_e_r_s

 Characters outside the Unicode "XIDStart" set are no longer allowed at
 the beginning of an identifier.  This means that certain accents and
 marks that normally follow an alphabetic character may no longer be the
 first character of an identifier.

TThhrreeaaddss aanndd PPrroocceesssseess _D_i_r_e_c_t_o_r_y _h_a_n_d_l_e_s _n_o_t _c_o_p_i_e_d _t_o _t_h_r_e_a_d_s

 On systems other than Windows that do not have a "fchdir" function,
 newly-created threads no longer inherit directory handles from their
 parent threads.  Such programs would usually have crashed anyway [perl
 #75154].

 _"_c_l_o_s_e_" _o_n _s_h_a_r_e_d _p_i_p_e_s

 To avoid deadlocks, the "close" function no longer waits for the child
 process to exit if the underlying file descriptor is still in use by
 another thread.  It returns true in such cases.

 _ff_oo_rr_kk_((_)) _e_m_u_l_a_t_i_o_n _w_i_l_l _n_o_t _w_a_i_t _f_o_r _s_i_g_n_a_l_l_e_d _c_h_i_l_d_r_e_n

 On Windows parent processes would not terminate until all forked children
 had terminated first.  However, "kill("KILL", ...)" is inherently
 unstable on pseudo-processes, and "kill("TERM", ...)" might not get
 delivered if the child is blocked in a system call.

 To avoid the deadlock and still provide a safe mechanism to terminate the
 hosting process, Perl now no longer waits for children that have been
 sent a SIGTERM signal.  It is up to the parent process to wwaaiittppiidd(()) for
 these children if child-cleanup processing must be allowed to finish.
 However, it is also then the responsibility of the parent to avoid the
 deadlock by making sure the child process can't be blocked on I/O.

 See perlfork for more information about the ffoorrkk(()) emulation on Windows.

CCoonnffiigguurraattiioonn _N_a_m_i_n_g _f_i_x_e_s _i_n _P_o_l_i_c_y___s_h_._S_H _m_a_y _i_n_v_a_l_i_d_a_t_e _P_o_l_i_c_y_._s_h

 Several long-standing typos and naming confusions in _P_o_l_i_c_y___s_h_._S_H have
 been fixed, standardizing on the variable names used in _c_o_n_f_i_g_._s_h.

 This will change the behaviour of _P_o_l_i_c_y_._s_h if you happen to have been
 accidentally relying on its incorrect behaviour.

 _P_e_r_l _s_o_u_r_c_e _c_o_d_e _i_s _r_e_a_d _i_n _t_e_x_t _m_o_d_e _o_n _W_i_n_d_o_w_s

 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 sseeeekk(())/tteellll(()), and even simply reading from "DATA" after
 filehandles have been flushed by a call to ssyysstteemm(()), backticks, ffoorrkk(())
 etc.

 The default build options for Windows have been changed to read Perl
 source code on Windows in text mode now.  ByteLoader will (hopefully) be
 updated on CPAN to automatically handle this situation [perl #28106].

DDeepprreeccaattiioonnss See also “Deprecated C APIs”.

OOmmiittttiinngg aa ssppaaccee bbeettwweeeenn aa rreegguullaarr eexxpprreessssiioonn aanndd ssuubbsseeqquueenntt wwoorrdd Omitting the space between a regular expression operator or its modifiers and the following word is deprecated. For example, “m/foo/sand $bar” is for now still parsed as “m/foo/s and $bar”, but will now issue a warning.

“”\\cc_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” could be. Now, a deprecation warning is raised if that character isn’t an ASCII character. Also, a deprecation warning is raised for “\c{” (which is the same as simply saying “;”).

“”\\bb{{“” aanndd “”\\BB{{“” In regular expressions, a literal “{” immediately following a “\b” (not in a bracketed character class) or a “\B{” is now deprecated to allow for its future use by Perl itself.

PPeerrll 44--eerraa ..ppll lliibbrraarriieess Perl bundles a handful of library files that predate Perl 5. This bundling is now deprecated for most of these files, which are now available from CPAN. The affected files now warn when run, if they were installed as part of the core.

 This is a mandatory warning, not obeying --XX or lexical warning bits.  The
 warning is modelled on that supplied by _d_e_p_r_e_c_a_t_e_._p_m for deprecated-in-
 core _._p_m libraries.  It points to the specific CPAN distribution that
 contains the _._p_l libraries.  The CPAN versions, of course, do not
 generate the warning.

LLiisstt aassssiiggnnmmeenntt ttoo $$[[ Assignment to $[ was deprecated and started to give warnings in Perl version 5.12.0. This version of Perl (5.14) now also emits a warning when assigning to $[ in list context. This fixes an oversight in 5.12.0.

UUssee ooff qqww((......)) aass ppaarreenntthheesseess Historically the parser fooled itself into thinking that “qw(…)” literals were always enclosed in parentheses, and as a result you could sometimes omit parentheses around them:

     for $x qw(a b c) { ... }

 The parser no longer lies to itself in this way.  Wrap the list literal
 in parentheses like this:

     for $x (qw(a b c)) { ... }

 This is being deprecated because the parentheses in "for $i (1,2,3) { ...
 }" are not part of expression syntax.  They are part of the statement
 syntax, with the "for" statement wanting literal parentheses.  The
 synthetic parentheses that a "qw" expression acquired were only intended
 to be treated as part of expression syntax.

 Note that this does not change the behaviour of cases like:

     use POSIX qw(setlocale localeconv);
     our @EXPORT = qw(foo bar baz);

 where parentheses were never required around the expression.

“”\\NN{{BBEELLLL}}“” #

 This is because Unicode is using that name for a different character.
 See "Unicode Version 6.0 is now supported (mostly)" for more explanation.

“”??PPAATTTTEERRNN??“” #

 "?PATTERN?" (without the initial "m") has been deprecated and now
 produces a warning.  This is to allow future use of "?" in new operators.
 The match-once functionality is still available as "m?PATTERN?".

TTiiee ffuunnccttiioonnss oonn ssccaallaarrss hhoollddiinngg ttyyppeegglloobbss Calling a tie function (“tie”, “tied”, “untie”) with a scalar argument acts on a filehandle if the scalar happens to hold a typeglob.

 This is a long-standing bug that will be removed in Perl 5.16, as there
 is currently no way to tie the scalar itself when it holds a typeglob,
 and no way to untie a scalar that has had a typeglob assigned to it.

 Now there is a deprecation warning whenever a tie function is used on a
 handle without an explicit "*".

UUsseerr--ddeeffiinneedd ccaassee--mmaappppiinngg This feature is being deprecated due to its many issues, as documented in “User-Defined Case Mappings (for serious hackers only)” in perlunicode. This feature will be removed in Perl 5.16. Instead use the CPAN module Unicode::Casing, which provides improved functionality.

DDeepprreeccaatteedd mmoodduulleess The following module will be removed from the core distribution in a future release, and should be installed from CPAN instead. Distributions on CPAN that require this should add it to their prerequisites. The core version of these module now issues a deprecation warning.

 If you ship a packaged version of Perl, either alone or as part of a
 larger system, then you should carefully consider the repercussions of
 core module deprecations.  You may want to consider shipping your default
 build of Perl with a package for the deprecated module that installs into
 "vendor" or "site" Perl library directories.  This will inhibit the
 deprecation warnings.

 Alternatively, you may want to consider patching _l_i_b_/_d_e_p_r_e_c_a_t_e_._p_m to
 provide deprecation warnings specific to your packaging system or
 distribution of Perl, consistent with how your packaging system or
 distribution manages a staged transition from a release where the
 installation of a single package provides the given functionality, to a
 later release where the system administrator needs to know to install
 multiple packages to get that same functionality.

 You can silence these deprecation warnings by installing the module in
 question from CPAN.  To install the latest version of it by role rather
 than by name, just install "Task::Deprecations::5_14".

 Devel::DProf
     We strongly recommend that you install and use Devel::NYTProf instead
     of Devel::DProf, as Devel::NYTProf offers significantly improved
     profiling and reporting.

PPeerrffoorrmmaannccee EEnnhhaanncceemmeennttss “"SSaaffee ssiiggnnaallss"” ooppttiimmiissaattiioonn Signal dispatch has been moved from the runloop into control ops. This should give a few percent speed increase, and eliminates nearly all the speed penalty caused by the introduction of “safe signals” in 5.8.0. Signals should still be dispatched within the same statement as they were previously. If this does _n_o_t happen, or if you find it possible to create uninterruptible loops, this is a bug, and reports are encouraged of how to recreate such issues.

OOppttiimmiissaattiioonn ooff sshhiifftt(()) aanndd ppoopp(()) ccaallllss wwiitthhoouutt aarrgguummeennttss Two fewer OPs are used for sshhiifftt(()) and ppoopp(()) calls with no argument (with implicit @). This change makes sshhiifftt(()) 5% faster than “shift @” on non-threaded perls, and 25% faster on threaded ones.

OOppttiimmiissaattiioonn ooff rreeggeexxpp eennggiinnee ssttrriinngg ccoommppaarriissoonn wwoorrkk 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.

RReegguullaarr eexxpprreessssiioonn ccoommppiillaattiioonn ssppeeeedd--uupp Compiling regular expressions has been made faster when upgrading the regex to utf8 is necessary but this isn’t known when the compilation begins.

SSttrriinngg aappppeennddiinngg iiss 110000 ttiimmeess ffaasstteerr When doing a lot of string appending, perls built to use the system’s “malloc” could end up allocating a lot more memory than needed in a inefficient way.

 "sv_grow", the function used to allocate more memory if necessary when
 appending to a string, has been taught to round up the memory it requests
 to a certain geometric progression, making it much faster on certain
 platforms and configurations.  On Win32, it's now about 100 times faster.

EElliimmiinnaattee “"PPLL__“” aacccceessssoorr ffuunnccttiioonnss uunnddeerr iitthhrreeaaddss When “MULTIPLICITY” was first developed, and interpreter state moved into an interpreter struct, thread- and interpreter-local “PL_*” variables were defined as macros that called accessor functions (returning the address of the value) outside the Perl core. The intent was to allow members within the interpreter struct to change size without breaking binary compatibility, so that bug fixes could be merged to a maintenance branch that necessitated such a size change. This mechanism was redundant and penalised well-behaved code. It has been removed.

FFrreeeeiinngg wweeaakk rreeffeerreenncceess When there are many weak references to an object, freeing that object can under some circumstances take O(_N_*_N) time to free, where _N is the number of references. The circumstances in which this can happen have been reduced [perl #75254]

LLeexxiiccaall aarrrraayy aanndd hhaasshh aassssiiggnnmmeennttss An earlier optimisation to speed up “my @array = …” and “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].

@@ uusseess lleessss mmeemmoorryy Previously, @_ 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].

SSiizzee ooppttiimmiissaattiioonnss ttoo SSVV aanndd HHVV ssttrruuccttuurreess “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, cases when this needs to be done should be rare.

 The order of structure elements in SV bodies has changed.  Effectively,
 the NV slot has swapped location with STASH and MAGIC.  As all access to
 SV members is via macros, this should be completely transparent.  This
 change allows the space saving for PVHVs documented above, and may reduce
 the memory allocation needed for PVIVs on some architectures.

 "XPV", "XPVIV", and "XPVNV" now allocate only the parts of the "SV" body
 they actually use, saving some space.

 Scalars containing regular expressions now allocate only the part of the
 "SV" body they actually use, saving some space.

MMeemmoorryy ccoonnssuummppttiioonn iimmpprroovveemmeennttss ttoo EExxppoorrtteerr The @EXPORT_FAIL AV is no longer created unless needed, hence neither is the typeglob backing it. This saves about 200 bytes for every package that uses Exporter but doesn’t use this functionality.

MMeemmoorryy ssaavviinnggss ffoorr wweeaakk rreeffeerreenncceess 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.

“”%%++“” aanndd “”%%--“” uussee lleessss mmeemmoorryy The bulk of the “Tie::Hash::NamedCapture” module used to be in the Perl core. It has now been moved to an XS module to reduce overhead for programs that do not use “%+” or “%-”.

MMuullttiippllee ssmmaallll iimmpprroovveemmeennttss ttoo tthhrreeaaddss The internal structures of threading now make fewer API calls and fewer allocations, resulting in noticeably smaller object code. Additionally, many thread context checks have been deferred so they’re done only as needed (although this is only possible for non-debugging builds).

AAddjjaacceenntt ppaaiirrss ooff nneexxttssttaattee ooppccooddeess aarree nnooww ooppttiimmiizzeedd aawwaayy Previously, in code such as

     use constant DEBUG => 0;

     sub GAK {
         warn if DEBUG;
         print "stuff\n";
     }

 the ops for "warn if DEBUG" would be folded to a "null" op ("ex-const"),
 but the "nextstate" op would remain, resulting in a runtime op dispatch
 of "nextstate", "nextstate", etc.

 The execution of a sequence of "nextstate" ops is indistinguishable from
 just the last "nextstate" op so the peephole optimizer now eliminates the
 first of a pair of "nextstate" ops except when the first carries a label,
 since labels must not be eliminated by the optimizer, and label usage
 isn't conclusively known at compile time.

MMoodduulleess aanndd PPrraaggmmaattaa NNeeww MMoodduulleess aanndd PPrraaggmmaattaa • CPAN::Meta::YAML 0.003 has been added as a dual-life module. It supports a subset of YAML sufficient for reading and writing _M_E_T_A_._y_m_l and _M_Y_M_E_T_A_._y_m_l 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.

 •   CPAN::Meta version 2.110440 has been added as a dual-life module.  It
     provides a standard library to read, interpret and write CPAN
     distribution metadata files (like _M_E_T_A_._j_s_o_n and _M_E_T_A_._y_m_l) that
     describe a distribution, its contents, and the requirements for
     building it and installing it.  The latest CPAN distribution metadata
     specification is included as CPAN::Meta::Spec and notes on changes in
     the specification over time are given in CPAN::Meta::History.

 •   HTTP::Tiny 0.012 has been added as a dual-life module.  It is a very
     small, simple HTTP/1.1 client designed for simple GET requests and
     file mirroring.  It has been added so that _C_P_A_N_._p_m and CPANPLUS can
     "bootstrap" HTTP access to CPAN using pure Perl without relying on
     external binaries like ccuurrll(1) or wwggeett(1).

 •   JSON::PP 2.27105 has been added as a dual-life module to allow CPAN
     clients to read _M_E_T_A_._j_s_o_n files in CPAN distributions.

 •   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.

 •   Perl::OSType 1.002 has been added as a dual-life module.  It maps
     Perl operating system names (like "dragonfly" or "MSWin32") to more
     generic types with standardized names (like "Unix" or "Windows").  It
     has been refactored out of Module::Build and ExtUtils::CBuilder and
     consolidates such mappings into a single location for easier
     maintenance.

 •   The following modules were added by the Unicode::Collate upgrade.
     See below for details.

     Unicode::Collate::CJK::Big5

     Unicode::Collate::CJK::GB2312

     Unicode::Collate::CJK::JISX0208

     Unicode::Collate::CJK::Korean

     Unicode::Collate::CJK::Pinyin

     Unicode::Collate::CJK::Stroke

 •   Version::Requirements version 0.101020 has been added as a dual-life
     module.  It provides a standard library to model and manipulates
     module prerequisites and version constraints defined in
     CPAN::Meta::Spec.

UUppddaatteedd MMoodduulleess aanndd PPrraaggmmaa • attributes has been upgraded from version 0.12 to 0.14.

 •   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 uunnzziipp(1) executable.

 •   Archive::Tar has been upgraded from version 1.54 to 1.76.

     Important changes since 1.54 include the following:

     •   Compatibility with busybox implementations of ttaarr(1).

     •   A fix so that wwrriittee(()) and ccrreeaattee__aarrcchhiivvee(()) close only filehandles
         they themselves opened.

     •   A bug was fixed regarding the exit code of extract_archive.

     •   The ppttaarr(1) utility has a new option to allow safe creation of
         tarballs without world-writable files on Windows, allowing those
         archives to be uploaded to CPAN.

     •   A new ppttaarrggrreepp(1) utility for using regular expressions against
         the contents of files in a tar archive.

     •   pax extended headers are now skipped.

 •   Attribute::Handlers has been upgraded from version 0.87 to 0.89.

 •   autodie has been upgraded from version 2.06_01 to 2.1001.

 •   AutoLoader has been upgraded from version 5.70 to 5.71.

 •   The B module has been upgraded from version 1.23 to 1.29.

     It no longer crashes when taking apart a "y///" containing characters
     outside the octet range or compiled in a "use utf8" scope.

     The size of the shared object has been reduced by about 40%, with no
     reduction in functionality.

 •   B::Concise has been upgraded from version 0.78 to 0.83.

     B::Concise marks rrvv22ssvv(()), rrvv22aavv(()), and rrvv22hhvv(()) ops with the new
     "OPpDEREF" flag as "DREFed".

     It no longer produces mangled output with the --ttrreeee option [perl
     #80632].

 •   B::Debug has been upgraded from version 1.12 to 1.16.

 •   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
     "%^H" or other state and a label.  The label was previously emitted
     first, but is now emitted last (5.12.1).

     The "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 $_ as it was fixed in [perl #20444].

     Deparsing of "our" followed by a variable with funny characters (as
     permitted under the "use utf8" pragma) has also been fixed [perl
     #33752].

 •   B::Lint has been upgraded from version 1.11_01 to 1.13.

 •   base has been upgraded from version 2.15 to 2.16.

 •   Benchmark has been upgraded from version 1.11 to 1.12.

 •   bignum has been upgraded from version 0.23 to 0.27.

 •   Carp has been upgraded from version 1.15 to 1.20.

     Carp now detects incomplete ccaalllleerr(()) overrides and avoids using bogus
     @DB::args.  To provide backtraces, Carp relies on particular
     behaviour of the ccaalllleerr(()) builtin.  Carp now detects if other code
     has overridden this with an incomplete implementation, and modifies
     its backtrace accordingly.  Previously incomplete overrides would
     cause incorrect values in backtraces (best case), or obscure fatal
     errors (worst case).

     This fixes certain cases of "Bizarre copy of ARRAY" caused by modules
     overriding ccaalllleerr(()) incorrectly (5.12.2).

     It now also avoids using regular expressions that cause Perl to load
     its Unicode tables, so as to avoid the "BEGIN not safe after errors"
     error that ensue if there has been a syntax error [perl #82854].

 •   CGI has been upgraded from version 3.48 to 3.52.

     This provides the following security fixes: the MIME boundary in
     mmuullttiippaarrtt__iinniitt(()) is now random and the handling of newlines embedded
     in header values has been improved.

 •   Compress::Raw::Bzip2 has been upgraded from version 2.024 to 2.033.

     It has been updated to use bbzziipp22(1) 1.0.6.

 •   Compress::Raw::Zlib has been upgraded from version 2.024 to 2.033.

 •   constant has been upgraded from version 1.20 to 1.21.

     Unicode constants work once more.  They have been broken since Perl

5.10.0 [CPAN RT #67525]. #

 •   CPAN has been upgraded from version 1.94_56 to 1.9600.

     Major highlights:

     •   much less configuration dialog hassle

     •   support for _M_E_T_A_/_M_Y_M_E_T_A_._j_s_o_n

     •   support for local::lib

     •   support for HTTP::Tiny to reduce the dependency on FTP sites

     •   automatic mirror selection

     •   iron out all known bugs in configure_requires

     •   support for distributions compressed with bbzziipp22(1)

     •   allow _F_o_o_/_B_a_r_._p_m on the command line to mean "Foo::Bar"

 •   CPANPLUS has been upgraded from version 0.90 to 0.9103.

     A change to _c_p_a_n_p_-_r_u_n_-_p_e_r_l resolves RT #55964
     <http://rt.cpan.org/Public/Bug/Display.html?id=55964> and RT #57106
     <http://rt.cpan.org/Public/Bug/Display.html?id=57106>, both of which
     related to failures to install distributions that use
     "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 _M_E_T_A_._j_s_o_n and _M_Y_M_E_T_A_._j_s_o_n.

 •   CPANPLUS::Dist::Build has been upgraded from version 0.46 to 0.54.

 •   Data::Dumper has been upgraded from version 2.125 to 2.130_02.

     The indentation used to be off when $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].

     Dumpxs no longer crashes with globs returned by *$io_ref [perl
     #72332].

 •   DB_File has been upgraded from version 1.820 to 1.821.

 •   DBM_Filter has been upgraded from version 0.03 to 0.04.

 •   Devel::DProf has been upgraded from version 20080331.00 to
     20110228.00.

     Merely loading Devel::DProf now no longer triggers profiling to
     start.  Both "use Devel::DProf" and "perl -d:DProf ..." behave as
     before and start the profiler.

     NNOOTTEE: Devel::DProf is deprecated and will be removed from a future
     version of Perl.  We strongly recommend that you install and use
     Devel::NYTProf instead, as it offers significantly improved profiling
     and reporting.

 •   Devel::Peek has been upgraded from version 1.04 to 1.07.

 •   Devel::SelfStubber has been upgraded from version 1.03 to 1.05.

 •   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.

 •   Digest::MD5 has been upgraded from version 2.39 to 2.51.

     It is now safe to use this module in combination with threads.

 •   Digest::SHA has been upgraded from version 5.47 to 5.61.

     "shasum" now more closely mimics sshhaa11ssuumm(1)/mmdd55ssuumm(1).

     "addfile" accepts all POSIX filenames.

     New SHA-512/224 and SHA-512/256 transforms (ref. NIST Draft FIPS
     180-4 [February 2011])

 •   DirHandle has been upgraded from version 1.03 to 1.04.

 •   Dumpvalue has been upgraded from version 1.13 to 1.16.

 •   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].

 •   Encode has been upgraded from version 2.39 to 2.42.

     Now, all 66 Unicode non-characters are treated the same way U+FFFF
     has always been treated: in cases when it was disallowed, all 66 are
     disallowed, and in cases where it warned, all 66 warn.

 •   Env has been upgraded from version 1.01 to 1.02.

 •   Errno has been upgraded from version 1.11 to 1.13.

     The implementation of Errno has been refactored to use about 55% less
     memory.

     On some platforms with unusual header files, like Win32 ggcccc(1) using
     "mingw64" headers, some constants that weren't actually error numbers
     have been exposed by Errno.  This has been fixed [perl #77416].

 •   Exporter has been upgraded from version 5.64_01 to 5.64_03.

     Exporter no longer overrides $SIG{__WARN__} [perl #74472]

 •   ExtUtils::CBuilder has been upgraded from version 0.27 to 0.280203.

 •   ExtUtils::Command has been upgraded from version 1.16 to 1.17.

 •   ExtUtils::Constant has been upgraded from 0.22 to 0.23.

     The AUTOLOAD helper code generated by "ExtUtils::Constant::ProxySubs"
     can now ccrrooaakk(()) for missing constants, or generate a complete
     "AUTOLOAD" subroutine in XS, allowing simplification of many modules
     that use it (Fcntl, File::Glob, GDBM_File, I18N::Langinfo, POSIX,
     Socket).

     ExtUtils::Constant::ProxySubs can now optionally push the names of
     all constants onto the package's @EXPORT_OK.

 •   ExtUtils::Install has been upgraded from version 1.55 to 1.56.

 •   ExtUtils::MakeMaker has been upgraded from version 6.56 to 6.57_05.

 •   ExtUtils::Manifest has been upgraded from version 1.57 to 1.58.

 •   ExtUtils::ParseXS has been upgraded from version 2.21 to 2.2210.

 •   Fcntl has been upgraded from version 1.06 to 1.11.

 •   File::Basename has been upgraded from version 2.78 to 2.82.

 •   File::CheckTree has been upgraded from version 4.4 to 4.41.

 •   File::Copy has been upgraded from version 2.17 to 2.21.

 •   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 _._/ to
     file names returned when the pattern is a relative glob with a drive
     specification, like _C_:_*_._p_l [perl #71712].

 •   File::Fetch has been upgraded from version 0.24 to 0.32.

     HTTP::Lite is now supported for the "http" scheme.

     The ffeettcchh(1) utility is supported on FreeBSD, NetBSD, and Dragonfly
     BSD for the "http" and "ftp" schemes.

 •   File::Find has been upgraded from version 1.15 to 1.19.

     It improves handling of backslashes on Windows, so that paths like
     _C_:_\_d_i_r_\_/_f_i_l_e are no longer generated [perl #71710].

 •   File::Glob has been upgraded from version 1.07 to 1.12.

 •   File::Spec has been upgraded from version 3.31 to 3.33.

     Several portability fixes were made in 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;
     ccaattppaatthh(()) returns an empty directory rather than the current
     directory if the input directory name is empty; and aabbss22rreell(())
     properly handles Unix-style input (5.12.2).

 •   File::stat has been upgraded from 1.02 to 1.05.

     The "-x" and "-X" file test operators now work correctly when run by
     the superuser.

 •   Filter::Simple has been upgraded from version 0.84 to 0.86.

 •   GDBM_File has been upgraded from 1.10 to 1.14.

     This fixes a memory leak when DBM filters are used.

 •   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].

 •   Hash::Util::FieldHash has been upgraded from version 1.04 to 1.09.

 •   I18N::Collate has been upgraded from version 1.01 to 1.02.

 •   I18N::Langinfo has been upgraded from version 0.03 to 0.08.

     llaannggiinnffoo(()) now defaults to using $_ if there is no argument given,
     just as the documentation has always claimed.

 •   I18N::LangTags has been upgraded from version 0.35 to 0.35_01.

 •   if has been upgraded from version 0.05 to 0.0601.

 •   IO has been upgraded from version 1.25_02 to 1.25_04.

     This version of IO includes a new 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.

 •   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).

 •   IPC::Open3 has been upgraded from 1.05 to 1.09.

     ooppeenn33(()) now produces an error if the "exec" call fails, allowing this
     condition to be distinguished from a child process that exited with a
     non-zero status [perl #72016].

     The internal xxcclloossee(()) 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].

 •   IPC::SysV has been upgraded from version 2.01 to 2.03.

 •   lib has been upgraded from version 0.62 to 0.63.

 •   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
     "Locale::Maketext::Guts::_compile()" when working with tainted values

(CPAN RT #40727). #

     "->maketext" calls now back up and restore $@ so error messages are
     not suppressed (CPAN RT #34182).

 •   Log::Message has been upgraded from version 0.02 to 0.04.

 •   Log::Message::Simple has been upgraded from version 0.06 to 0.08.

 •   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 "sqrt($int)" from crashing under "use bigrat".
     [perl #73534].

 •   Math::BigInt::FastCalc has been upgraded from version 0.19 to 0.28.

 •   Math::BigRat has been upgraded from version 0.24 to 0.26_02.

 •   Memoize has been upgraded from version 1.01_03 to 1.02.

 •   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 eennccooddee__bbaassee6644uurrll(()) and ddeeccooddee__bbaassee6644uurrll(()) functions to
     process the base64 scheme for "URL applications".

 •   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 on the version pragma directly.  Module::Build::ModuleInfo has
     been deprecated in favor of a standalone copy called
     Module::Metadata.  Module::Build::YAML has been deprecated in favor
     of CPAN::Meta::YAML.

     Module::Build now also generates _M_E_T_A_._j_s_o_n and _M_Y_M_E_T_A_._j_s_o_n files in
     accordance with version 2 of the CPAN distribution metadata
     specification, CPAN::Meta::Spec.  The older format _M_E_T_A_._y_m_l and
     _M_Y_M_E_T_A_._y_m_l files are still generated.

 •   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 "Filespec" module.  That module never existed in
     core.  The scripts generating Module::CoreList confused it with
     VMS::Filespec, which actually is a core module as of Perl 5.8.7.

 •   Module::Load has been upgraded from version 0.16 to 0.18.

 •   Module::Load::Conditional has been upgraded from version 0.34 to
     0.44.

 •   The mro pragma has been upgraded from version 1.02 to 1.07.

 •   NDBM_File has been upgraded from version 1.08 to 1.12.

     This fixes a memory leak when DBM filters are used.

 •   Net::Ping has been upgraded from version 2.36 to 2.38.

 •   NEXT has been upgraded from version 0.64 to 0.65.

 •   Object::Accessor has been upgraded from version 0.36 to 0.38.

 •   ODBM_File has been upgraded from version 1.07 to 1.10.

     This fixes a memory leak when DBM filters are used.

 •   Opcode has been upgraded from version 1.15 to 1.18.

 •   The overload pragma has been upgraded from 1.10 to 1.13.

     "overload::Method" can now handle subroutines that are themselves
     blessed into overloaded classes [perl #71998].

     The documentation has greatly improved.  See "Documentation" below.

 •   Params::Check has been upgraded from version 0.26 to 0.28.

 •   The parent pragma has been upgraded from version 0.223 to 0.225.

 •   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
     CPAN::Meta::YAML and JSON::PP, which are now part of the Perl core.

 •   PerlIO::encoding has been upgraded from version 0.12 to 0.14.

 •   PerlIO::scalar has been upgraded from 0.07 to 0.11.

     A rreeaadd(()) after a sseeeekk(()) beyond the end of the string no longer thinks
     it has data to read [perl #78716].

 •   PerlIO::via has been upgraded from version 0.09 to 0.11.

 •   Pod::Html has been upgraded from version 1.09 to 1.11.

 •   Pod::LaTeX has been upgraded from version 0.58 to 0.59.

 •   Pod::Perldoc has been upgraded from version 3.15_02 to 3.15_03.

 •   Pod::Simple has been upgraded from version 3.13 to 3.16.

 •   POSIX has been upgraded from 1.19 to 1.24.

     It now includes constants for POSIX signal constants.

 •   The re pragma has been upgraded from version 0.11 to 0.18.

     The "use re '/flags'" subpragma is new.

     The rreeggmmuusstt(()) function used to crash when called on a regular
     expression belonging to a pluggable engine.  Now it croaks instead.

     rreeggmmuusstt(()) no longer leaks memory.

 •   Safe has been upgraded from version 2.25 to 2.29.

     Coderefs returned by rreevvaall(()) and rrddoo(()) are now wrapped via
     wwrraapp__ccooddee__rreeffss(()) (5.12.1).

     This fixes a possible infinite loop when looking for coderefs.

     It adds several "version::vxs::*" routines to the default share.

 •   SDBM_File has been upgraded from version 1.06 to 1.09.

 •   SelfLoader has been upgraded from 1.17 to 1.18.

     It now works in taint mode [perl #72062].

 •   The sigtrap pragma has been upgraded from version 1.04 to 1.05.

     It no longer tries to modify read-only arguments when generating a
     backtrace [perl #72340].

 •   Socket has been upgraded from version 1.87 to 1.94.

     See "Improved IPv6 support" above.

 •   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
     $Storable::accept_future_minor to a "FALSE" value will see errors
     (see "FORWARD COMPATIBILITY" in Storable for more details).

     Freezing no longer gets confused if the Perl stack gets reallocated
     during freezing [perl #80074].

 •   Sys::Hostname has been upgraded from version 1.11 to 1.16.

 •   Term::ANSIColor has been upgraded from version 2.02 to 3.00.

 •   Term::UI has been upgraded from version 0.20 to 0.26.

 •   Test::Harness has been upgraded from version 3.17 to 3.23.

 •   Test::Simple has been upgraded from version 0.94 to 0.98.

     Among many other things, subtests without a "plan" or "no_plan" now
     have an implicit ddoonnee__tteessttiinngg(()) added to them.

 •   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: "down_nb" and "down_force".

 •   Thread::Queue has been upgraded from version 2.11 to 2.12.

 •   The threads pragma has been upgraded from version 1.75 to 1.83.

 •   The threads::shared pragma has been upgraded from version 1.32 to
     1.37.

 •   Tie::Hash has been upgraded from version 1.03 to 1.04.

     Calling "Tie::Hash->TIEHASH()" used to loop forever.  Now it
     "croak"s.

 •   Tie::Hash::NamedCapture has been upgraded from version 0.06 to 0.08.

 •   Tie::RefHash has been upgraded from version 1.38 to 1.39.

 •   Time::HiRes has been upgraded from version 1.9719 to 1.9721_01.

 •   Time::Local has been upgraded from version 1.1901_01 to 1.2000.

 •   Time::Piece has been upgraded from version 1.15_01 to 1.20_01.

 •   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: _a_r_,
     _b_e_, _b_g_, _d_e_____p_h_o_n_e_b_o_o_k_, _h_u_, _h_y_, _k_k_, _m_k_, _n_s_o_, _o_m_, _t_n_, _v_i_, _h_r_, _i_g_, _j_a_,
     _k_o_, _r_u_, _s_q_, _s_e_, _s_r_, _t_o_, _u_k_, _z_h_, _z_h_____b_i_g_5_h_a_n_, _z_h_____g_b_2_3_1_2_h_a_n_,
     _z_h_____p_i_n_y_i_n, and _z_h_____s_t_r_o_k_e.

     The following modules have been added:

     Unicode::Collate::CJK::Big5 for "zh__big5han" which makes tailoring
     of CJK Unified Ideographs in the order of CLDR's big5han ordering.

     Unicode::Collate::CJK::GB2312 for "zh__gb2312han" which makes
     tailoring of CJK Unified Ideographs in the order of CLDR's gb2312han
     ordering.

     Unicode::Collate::CJK::JISX0208 which makes tailoring of 6355 kanji
     (CJK Unified Ideographs) in the JIS X 0208 order.

     Unicode::Collate::CJK::Korean which makes tailoring of CJK Unified
     Ideographs in the order of CLDR's Korean ordering.

     Unicode::Collate::CJK::Pinyin for "zh__pinyin" which makes tailoring
     of CJK Unified Ideographs in the order of CLDR's pinyin ordering.

     Unicode::Collate::CJK::Stroke for "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.

 •   Unicode::Normalize has been upgraded from version 1.03 to 1.10.

 •   Unicode::UCD has been upgraded from version 0.27 to 0.32.

     A new function, UUnniiccooddee::::UUCCDD::::nnuumm(()), has been added.  This function
     returns the numeric value of the string passed it or "undef" if the
     string in its entirety has no "safe" numeric value.  (For more
     detail, and for the definition of "safe", see "nnuumm(())" in
     Unicode::UCD.)

     This upgrade also includes several bug fixes:

     cchhaarriinnffoo(())
         •   It is now updated to Unicode Version 6.0.0 with _C_o_r_r_i_g_e_n_d_u_m
             _#_8, excepting that, just as with Perl 5.14, the code point at
             U+1F514 has no name.

         •   Hangul syllable code points have the correct names, and their
             decompositions are always output without requiring
             Lingua::KO::Hangul::Util to be installed.

         •   CJK (Chinese-Japanese-Korean) code points U+2A700 to U+2B734
             and U+2B740 to U+2B81D are now properly handled.

         •   Numeric values are now output for those CJK code points that
             have them.

         •   Names output for code points with multiple aliases are now
             the corrected ones.

     cchhaarrssccrriipptt(())
         This now correctly returns "Unknown" instead of "undef" for the
         script of a code point that hasn't been assigned another one.

     cchhaarrbblloocckk(())
         This now correctly returns "No_Block" instead of "undef" for the
         block of a code point that hasn't been assigned to another one.

 •   The version pragma has been upgraded from 0.82 to 0.88.

     Because of a bug, now fixed, the iiss__ssttrriicctt(()) and iiss__llaaxx(()) functions
     did not work when exported (5.12.1).

 •   The warnings pragma has been upgraded from version 1.09 to 1.12.

     Calling "use warnings" without arguments is now significantly more
     efficient.

 •   The warnings::register pragma has been upgraded from version 1.01 to
     1.02.

     It is now possible to register warning categories other than the
     names of packages using warnings::register.  See ppeerrlllleexxwwaarrnn(1) for
     more information.

 •   XSLoader has been upgraded from version 0.10 to 0.13.

 •   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
     "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.

 •   The Win32 module has been upgraded from version 0.39 to 0.44.

     This release has several new functions: WWiinn3322::::GGeettSSyysstteemmMMeettrriiccss(()),
     WWiinn3322::::GGeettPPrroodduuccttIInnffoo(()), WWiinn3322::::GGeettOOSSDDiissppllaayyNNaammee(()).

     The names returned by WWiinn3322::::GGeettOOSSNNaammee(()) and
     WWiinn3322::::GGeettOOSSDDiissppllaayyNNaammee(()) have been corrected.

 •   XS::Typemap has been upgraded from version 0.03 to 0.05.

RReemmoovveedd MMoodduulleess aanndd PPrraaggmmaattaa As promised in Perl 5.12.0’s release notes, the following modules have been removed from the core distribution, and if needed should be installed from CPAN instead.

 •   Class::ISA has been removed from the Perl core.  Prior version was
     0.36.

 •   Pod::Plainer has been removed from the Perl core.  Prior version was
     1.02.

 •   Switch has been removed from the Perl core.  Prior version was 2.16.

 The removal of Shell has been deferred until after 5.14, as the
 implementation of Shell shipped with 5.12.0 did not correctly issue the
 warning that it was to be removed from core.

DDooccuummeennttaattiioonn NNeeww DDooccuummeennttaattiioonn _p_e_r_l_g_p_l

 perlgpl has been updated to contain GPL version 1, as is included in the
 _R_E_A_D_M_E distributed with Perl (5.12.1).

 _P_e_r_l _5_._1_2_._x _d_e_l_t_a _f_i_l_e_s

 The perldelta files for Perl 5.12.1 to 5.12.3 have been added from the
 maintenance branch: perl5121delta, perl5122delta, perl5123delta.

 _p_e_r_l_p_o_d_s_t_y_l_e

 New style guide for POD documentation, split mostly from the NOTES
 section of the ppoodd22mmaann(1) manpage.

 _p_e_r_l_s_o_u_r_c_e_, _p_e_r_l_i_n_t_e_r_p_, _p_e_r_l_h_a_c_k_t_u_t_, _a_n_d _p_e_r_l_h_a_c_k_t_i_p_s

 See "perlhack and perlrepository revamp", below.

CChhaannggeess ttoo EExxiissttiinngg DDooccuummeennttaattiioonn _p_e_r_l_m_o_d_l_i_b _i_s _n_o_w _c_o_m_p_l_e_t_e

 The perlmodlib manpage that came with Perl 5.12.0 was missing several
 modules due to a bug in the script that generates the list.  This has
 been fixed [perl #74332] (5.12.1).

 _R_e_p_l_a_c_e _i_n_c_o_r_r_e_c_t _t_r_/_/_/ _t_a_b_l_e _i_n _p_e_r_l_e_b_c_d_i_c

 perlebcdic contains a helpful table to use in "tr///" to convert between
 EBCDIC and Latin1/ASCII.  The table was the inverse of the one it
 describes, though the code that used the table worked correctly for the
 specific example given.

 The table has been corrected and the sample code changed to correspond.

 The table has also been changed to hex from octal, and the recipes in the
 pod have been altered to print out leading zeros to make all values the
 same length.

 _T_r_i_c_k_s _f_o_r _u_s_e_r_-_d_e_f_i_n_e_d _c_a_s_i_n_g

 perlunicode now contains an explanation of how to override, mangle and
 otherwise tweak the way Perl handles upper-, lower- and other-case
 conversions on Unicode data, and how to provide scoped changes to alter
 one's own code's behaviour without stomping on anybody else's.

 _I_N_S_T_A_L_L _e_x_p_l_i_c_i_t_l_y _s_t_a_t_e_s _t_h_a_t _P_e_r_l _r_e_q_u_i_r_e_s _a _C_8_9 _c_o_m_p_i_l_e_r

 This was already true, but it's now Officially Stated For The Record
 (5.12.2).

 _E_x_p_l_a_n_a_t_i_o_n _o_f _"_\_x_H_H_" _a_n_d _"_\_o_O_O_O_" _e_s_c_a_p_e_s

 perlop has been updated with more detailed explanation of these two
 character escapes.

 _--_00_NN_NN_NN _s_w_i_t_c_h

 In perlrun, the behaviour of the --00NNNNNN switch for --00440000 or higher has
 been clarified (5.12.2).

 _M_a_i_n_t_e_n_a_n_c_e _p_o_l_i_c_y

 perlpolicy now contains the policy on what patches are acceptable for
 maintenance branches (5.12.1).

 _D_e_p_r_e_c_a_t_i_o_n _p_o_l_i_c_y

 perlpolicy now contains the policy on compatibility and deprecation along
 with definitions of terms like "deprecation" (5.12.2).

 _N_e_w _d_e_s_c_r_i_p_t_i_o_n_s _i_n _p_e_r_l_d_i_a_g

 The following existing diagnostics are now documented:

 •   Ambiguous use of %c resolved as operator %c

 •   Ambiguous use of %c{%s} resolved to %c%s

 •   Ambiguous use of %c{%s[...]} resolved to %c%s[...]

 •   Ambiguous use of %c{%s{...}} resolved to %c%s{...}

 •   Ambiguous use of -%s resolved as -&%s()

 •   Invalid strict version format (%s)

 •   Invalid version format (%s)

 •   Invalid version object

 _p_e_r_l_b_o_o_k

 perlbook has been expanded to cover many more popular books.

 _"_S_v_T_R_U_E_" _m_a_c_r_o

 The documentation for the "SvTRUE" macro in perlapi was simply wrong in
 stating that get-magic is not processed.  It has been corrected.

 _o_p _m_a_n_i_p_u_l_a_t_i_o_n _f_u_n_c_t_i_o_n_s

 Several API functions that process optrees have been newly documented.

 _p_e_r_l_v_a_r _r_e_v_a_m_p

 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.  perlvar also has a new section for deprecated variables to
 note when they were removed.

 _A_r_r_a_y _a_n_d _h_a_s_h _s_l_i_c_e_s _i_n _s_c_a_l_a_r _c_o_n_t_e_x_t

 These are now documented in perldata.

 _"_u_s_e _l_o_c_a_l_e_" _a_n_d _f_o_r_m_a_t_s

 perlform and perllocale have been corrected to state that "use locale"
 affects formats.

 _o_v_e_r_l_o_a_d

 overload's documentation has practically undergone a rewrite.  It is now
 much more straightforward and clear.

 _p_e_r_l_h_a_c_k _a_n_d _p_e_r_l_r_e_p_o_s_i_t_o_r_y _r_e_v_a_m_p

 The 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, perlsource, perlinterp,
 perlhacktut, and perlhacktips.  This technical content has been only
 lightly edited.

 The perlrepository document has been renamed to 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.

 _T_i_m_e_:_:_P_i_e_c_e _e_x_a_m_p_l_e_s

 Examples in perlfaq4 have been updated to show the use of Time::Piece.

DDiiaaggnnoossttiiccss 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 perldiag.

NNeeww DDiiaaggnnoossttiiccss _N_e_w _E_r_r_o_r_s

 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].

 Insecure user-defined property %s
     Perl detected tainted data when trying to compile a regular
     expression that contains a call to a user-defined character property
     function, meaning "\p{IsFoo}" or "\p{InFoo}".  See "User-Defined
     Character Properties" in perlunicode and perlsec.

 panic: gp_free failed to free glob pointer - something is repeatedly
 re-creating entries
     This new error is triggered if a destructor called on an object in a
     typeglob that is being freed creates a new typeglob entry containing
     an object with a destructor that creates a new entry containing an
     object etc.

 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.

 refcnt: fd %d%s
     This new error only occurs if an internal consistency check fails
     when a pipe is about to be closed.

 Regexp modifier "/%c" may not appear twice
     The regular expression pattern has one of the mutually exclusive
     modifiers repeated.

 Regexp modifiers "/%c" and "/%c" are mutually exclusive
     The regular expression pattern has more than one of the mutually
     exclusive modifiers.

 Using !~ with %s doesn't make sense
     This error occurs when "!~" is used with "s///r" or "y///r".

 _N_e_w _W_a_r_n_i_n_g_s

 "\b{" is deprecated; use "\b\{" instead
 "\B{" is deprecated; use "\B\{" instead
     Use of an unescaped "{" immediately following a "\b" or "\B" is now
     deprecated in order to reserve its use for Perl itself in a future
     release.

 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.

 Use of qw(...) as parentheses is deprecated
     See "Use of qw(...) as parentheses", above, for details.

CChhaannggeess ttoo EExxiissttiinngg DDiiaaggnnoossttiiccss • The “Variable $foo is not imported” warning that precedes a “strict ‘vars’” error has now been assigned the “misc” category, so that “no warnings” will suppress it [perl #73712].

 •   wwaarrnn(()) and ddiiee(()) now produce "Wide character" warnings when fed a
     character outside the byte range if "STDERR" is a byte-sized handle.

 •   The "Layer does not match this perl" error message has been replaced
     with these more helpful messages [perl #73754]:

     •   PerlIO layer function table size (%d) does not match size
         expected by this perl (%d)

     •   PerlIO layer instance size (%d) does not match size expected by
         this perl (%d)

 •   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 "use constant",
     since the value of the constant may not be known at the time the
     program is written [perl #77762].

 •   Previously, if none of the ggeetthhoossttbbyyaaddddrr(()), ggeetthhoossttbbyynnaammee(()) and
     ggeetthhoosstteenntt(()) functions were implemented on a given platform, they
     would all die with the message "Unsupported socket function
     'gethostent' called", with analogous messages for getnet*() and
     getserv*().  This has been corrected.

 •   The warning message about unrecognized regular expression escapes
     passed through has been changed to include any literal "{" following
     the two-character escape.  For example, "\q{" is now emitted instead
     of "\q".

UUttiilliittyy CChhaannggeess _pp_ee_rr_ll_bb_uu_gg_(_1_)

 •   perlbug now looks in the EMAIL environment variable for a return
     address if the REPLY-TO and REPLYTO variables are empty.

 •   perlbug did not previously generate a "From:" header, potentially
     resulting in dropped mail; it now includes that header.

 •   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].

 •   perlbug now always gives the reporter a chance to change the email
     address it guesses for them (5.12.2).

 •   perlbug should no longer warn about uninitialized values when using
     the --dd and --vv options (5.12.2).

 _p_e_r_l_5_d_b_._p_l

 •   The remote terminal works after forking and spawns new sessions, one
     per forked process.

 _p_t_a_r_g_r_e_p

 •   ptargrep is a new utility to apply pattern matching to the contents
     of files  in a tar archive.  It comes with "Archive::Tar".

CCoonnffiigguurraattiioonn aanndd CCoommppiillaattiioonn See also “Naming fixes in Policy_sh.SH may invalidate Policy.sh”, above.

 •   CCINCDIR and CCLIBDIR for the mingw64 cross-compiler are now
     correctly under _$_(_C_C_H_O_M_E_)_\_m_i_n_g_w_\_i_n_c_l_u_d_e and _\_l_i_b rather than
     immediately below _$_(_C_C_H_O_M_E_).

     This means the "incpath", "libpth", "ldflags", "lddlflags" and
     "ldflags_nolargefiles" values in _C_o_n_f_i_g_._p_m and _C_o_n_f_i_g___h_e_a_v_y_._p_l are
     now set correctly.

 •   "make test.valgrind" has been adjusted to account for _c_p_a_n_/_d_i_s_t_/_e_x_t
     separation.

 •   On compilers that support it, --WWwwrriittee--ssttrriinnggss is now added to cflags
     by default.

 •   The 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.

 •   The previous default size of a PerlIO buffer (4096 bytes) has been
     increased to the larger of 8192 bytes and your local BUFSIZ.
     Benchmarks show that doubling this decade-old default increases read
     and write performance by around 25% to 50% when using the default
     layers of perlio on top of unix.  To choose a non-default size, such
     as to get back the old value or to obtain an even larger value,
     configure with:

          ./Configure -Accflags=-DPERLIOBUF_DEFAULT_BUFSIZ=N

     where N is the desired size in bytes; it should probably be a
     multiple of your page size.

 •   An "incompatible operand types" error in ternary expressions when
     building with "clang" has been fixed (5.12.2).

 •   Perl now skips setuid File::Copy tests on partitions it detects
     mounted as "nosuid" (5.12.2).

PPllaattffoorrmm SSuuppppoorrtt NNeeww PPllaattffoorrmmss AIX Perl now builds on AIX 4.2 (5.12.1).

DDiissccoonnttiinnuueedd PPllaattffoorrmmss 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.

 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.

PPllaattffoorrmm--SSppeecciiffiicc NNootteess

_A_I_X #

 •   _R_E_A_D_M_E_._a_i_x has been updated with information about the XL C/C++ V11
     compiler suite (5.12.2).

_A_R_M #

 •   The "d_u32align" configuration probe on ARM has been fixed (5.12.2).

 _C_y_g_w_i_n

 •   MakeMaker has been updated to build manpages on cygwin.

 •   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
     <http://www.tishler.net/jason/software/rebase/rebase-2.4.2.README>
     for more information.

 •   Support for the standard cygwin dll prefix (needed for FFIs)

 •   Updated build hints file

 _F_r_e_e_B_S_D _7

 •   FreeBSD 7 no longer contains _/_u_s_r_/_b_i_n_/_o_b_j_f_o_r_m_a_t.  At build time, Perl
     now skips the _o_b_j_f_o_r_m_a_t check for versions 7 and higher and assumes

ELF (5.12.1). #

_H_P_-_U_X #

 •   Perl now allows --DDuussee6644bbiittiinntt without promoting to "use64bitall" on

HP-UX (5.12.1). #

_I_R_I_X #

 •   Conversion of strings to floating-point numbers is now more accurate
     on IRIX systems [perl #32380].

 _M_a_c _O_S _X

 •   Early versions of Mac OS X (Darwin) had buggy implementations of the
     sseettrreeggiidd(()), sseettrreeuuiidd(()), setrgid(,) and sseettrruuiidd(()) 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].

 _M_i_r_B_S_D

 •   Previously if you built Perl with a shared _l_i_b_p_e_r_l_._s_o on MirBSD (the
     default config), it would work up to the installation; however, once
     installed, it would be unable to find _l_i_b_p_e_r_l.  Path handling is now
     treated as in the other BSD dialects.

 _N_e_t_B_S_D

 •   The NetBSD hints file has been changed to make the system malloc the
     default.

 _O_p_e_n_B_S_D

 •   OpenBSD > 3.7 has a new malloc implementation which is _m_m_a_p-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].

 _O_p_e_n_V_O_S

 •   Perl now builds again with OpenVOS (formerly known as Stratus VOS)
     [perl #78132] (5.12.3).

 _S_o_l_a_r_i_s

 •   DTrace is now supported on Solaris.  There used to be build failures,
     but these have been fixed [perl #73630] (5.12.3).

_V_M_S #

 •   Extension building on older (pre 7.3-2) VMS systems was broken
     because configure.com hit the DCL symbol length limit of 1K.  We now
     work within this limit when assembling the list of extensions in the
     core build (5.12.1).

 •   We fixed configuring and building Perl with --UUuusseeppeerrlliioo (5.12.1).

 •   "PerlIOUnix_open" now honours the default permissions on VMS.

     When "perlio" became the default and "unix" became the default bottom
     layer, the most common path for creating files from Perl became
     "PerlIOUnix_open", which has always explicitly used 0666 as the
     permission mask.  This prevents inheriting permissions from RMS
     defaults and ACLs, so to avoid that problem, we now pass 0777 to
     ooppeenn(()).  In the VMS CRTL, 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).

 •   The shortening of symbols longer than 31 characters in the core C
     sources and in extensions is now by default done by the C compiler
     rather than by xsubpp (which could only do so for generated symbols
     in XS code).  You can reenable xsubpp's symbol shortening by
     configuring with -Uuseshortenedsymbols, but you'll have some work to
     do to get the core sources to compile.

 •   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.

 •   _g_i_t___v_e_r_s_i_o_n_._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).

 •   Several memory leaks in ssttaatt(()) have been fixed (5.12.2).

 •   A memory leak in PPeerrll__rreennaammee(()) due to a double allocation has been
     fixed (5.12.2).

 •   A memory leak in vvmmss__ffiidd__ttoo__nnaammee(()) (used by rreeaallppaatthh(()) and
     rreeaallnnaammee(())> has been fixed (5.12.2).

 _W_i_n_d_o_w_s

 See also "ffoorrkk(()) emulation will not wait for signalled children" and
 "Perl source code is read in text mode on Windows", above.

 •   Fixed build process for SDK2003SP1 compilers.

 •   Compilation with Visual Studio 2010 is now supported.

 •   When using old 32-bit compilers, the define "_USE_32BIT_TIME_T" is
     now set in $Config{ccflags}.  This improves portability when
     compiling XS extensions using new compilers, but for a Perl compiled
     with old 32-bit compilers.

 •   $Config{gccversion} is now set correctly when Perl is built using the
     mingw64 compiler from <http://mingw64.org> [perl #73754].

 •   When building Perl with the mingw64 x64 cross-compiler "incpath",
     "libpth", "ldflags", "lddlflags" and "ldflags_nolargefiles" values in
     _C_o_n_f_i_g_._p_m and _C_o_n_f_i_g___h_e_a_v_y_._p_l were not previously being set correctly
     because, with that compiler, the include and lib directories are not
     immediately below "$(CCHOME)" (5.12.2).

 •   The build process proceeds more smoothly with mingw and dmake when
     _C_:_\_M_S_Y_S_\_b_i_n is in the PATH, due to a "Cwd" fix.

 •   Support for building with Visual C++ 2010 is now underway, but is not
     yet complete.  See _R_E_A_D_M_E_._w_i_n_3_2 or perlwin32 for more details.

 •   The option to use an externally-supplied ccrryypptt(()), or to build with no
     ccrryypptt(()) at all, has been removed.  Perl supplies its own ccrryypptt(())
     implementation for Windows, and the political situation that required
     this part of the distribution to sometimes be omitted is long gone.

IInntteerrnnaall CChhaannggeess NNeeww AAPPIIss _C_L_O_N_E___P_A_R_A_M_S _s_t_r_u_c_t_u_r_e _a_d_d_e_d _t_o _e_a_s_e _c_o_r_r_e_c_t _t_h_r_e_a_d _c_r_e_a_t_i_o_n

 Modules that create threads should now create "CLONE_PARAMS" structures
 by calling the new function PPeerrll__cclloonnee__ppaarraammss__nneeww(()), and free them with
 PPeerrll__cclloonnee__ppaarraammss__ddeell(()).  This will ensure compatibility with any future
 changes to the internals of the "CLONE_PARAMS" structure layout, and that
 it is correctly allocated and initialised.

 _N_e_w _p_a_r_s_i_n_g _f_u_n_c_t_i_o_n_s

 Several functions have been added for parsing Perl statements and
 expressions.  These functions are meant to be used by XS code invoked
 during Perl parsing, in a recursive-descent manner, to allow modules to
 augment the standard Perl syntax.

 •   ppaarrssee__ssttmmttsseeqq(()) parses a sequence of statements, up to closing brace
     or EOF.

 •   ppaarrssee__ffuullllssttmmtt(()) parses a complete Perl statement, including optional
     label.

 •   ppaarrssee__bbaarreessttmmtt(()) parses a statement without a label.

 •   ppaarrssee__bblloocckk(()) parses a code block.

 •   ppaarrssee__llaabbeell(()) parses a statement label, separate from statements.

 •   "parse_fullexpr()", "parse_listexpr()", "parse_termexpr()", and
     "parse_arithexpr()" parse expressions at various precedence levels.

 _H_i_n_t_s _h_a_s_h _A_P_I

 A new C API for introspecting the hinthash "%^H" at runtime has been
 added.  See "cop_hints_2hv", "cop_hints_fetchpvn", "cop_hints_fetchpvs",
 "cop_hints_fetchsv", and "hv_copy_hints_hv" in perlapi for details.

 A new, experimental API has been added for accessing the internal
 structure that Perl uses for "%^H".  See the functions beginning with
 "cophh_" in perlapi.

 _C _i_n_t_e_r_f_a_c_e _t_o _cc_aa_ll_ll_ee_rr_((_))

 The "caller_cx" function has been added as an XSUB-writer's equivalent of
 ccaalllleerr(()).  See perlapi for details.

 _C_u_s_t_o_m _p_e_r_-_s_u_b_r_o_u_t_i_n_e _c_h_e_c_k _h_o_o_k_s

 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
 "entersub" op checker, but the new mechanism makes it easy to tie the
 hook to a specific subroutine.  See "cv_set_call_checker" in perlapi.

 To help in writing custom check hooks, several subtasks within standard
 "entersub" op checking have been separated out and exposed in the API.

 _I_m_p_r_o_v_e_d _s_u_p_p_o_r_t _f_o_r _c_u_s_t_o_m _O_P_s

 Custom ops can now be registered with the new "custom_op_register" C
 function and the "XOP" structure.  This will make it easier to add new
 properties of custom ops in the future.  Two new properties have been
 added already, "xop_class" and "xop_peep".

 "xop_class" is one of the OA_*OP constants.  It allows B and other
 introspection mechanisms to work with custom ops that aren't BASEOPs.
 "xop_peep" is a pointer to a function that will be called for ops of this
 type from "Perl_rpeep".

 See "Custom Operators" in perlguts and "Custom Operators" in perlapi for
 more detail.

 The old "PL_custom_op_names"/"PL_custom_op_descs" interface is still
 supported but discouraged.

 _S_c_o_p_e _h_o_o_k_s

 It is now possible for XS code to hook into Perl's lexical scope
 mechanism at compile time, using the new "Perl_blockhook_register"
 function.  See "Compile-time scope hooks" in perlguts.

 _T_h_e _r_e_c_u_r_s_i_v_e _p_a_r_t _o_f _t_h_e _p_e_e_p_h_o_l_e _o_p_t_i_m_i_z_e_r _i_s _n_o_w _h_o_o_k_a_b_l_e

 In addition to "PL_peepp", for hooking into the toplevel peephole
 optimizer, a "PL_rpeepp" is now available to hook into the optimizer
 recursing into side-chains of the optree.

 _N_e_w _n_o_n_-_m_a_g_i_c_a_l _v_a_r_i_a_n_t_s _o_f _e_x_i_s_t_i_n_g _f_u_n_c_t_i_o_n_s

 The following functions/macros have been added to the API.  The *_nomg
 macros are equivalent to their non-"_nomg" variants, except that they
 ignore get-magic.  Those ending in "_flags" allow one to specify whether
 get-magic is processed.

   sv_2bool_flags
   SvTRUE_nomg
   sv_2nv_flags
   SvNV_nomg
   sv_cmp_flags
   sv_cmp_locale_flags
   sv_eq_flags
   sv_collxfrm_flags

 In some of these cases, the non-"_flags" functions have been replaced
 with wrappers around the new functions.

 _p_v_/_p_v_s_/_s_v _v_e_r_s_i_o_n_s _o_f _e_x_i_s_t_i_n_g _f_u_n_c_t_i_o_n_s

 Many functions ending with pvn now have equivalent "pv/pvs/sv" versions.

 _L_i_s_t _o_p_-_b_u_i_l_d_i_n_g _f_u_n_c_t_i_o_n_s

 List op-building functions have been added to the API.  See
 op_append_elem, op_append_list, and op_prepend_elem in perlapi.

_”_L_I_N_K_L_I_S_T_" #

 The LINKLIST macro, part of op building that constructs the execution-
 order op chain, has been added to the API.

 _L_o_c_a_l_i_s_a_t_i_o_n _f_u_n_c_t_i_o_n_s

 The "save_freeop", "save_op", "save_pushi32ptr" and "save_pushptrptr"
 functions have been added to the API.

 _S_t_a_s_h _n_a_m_e_s

 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 "HvENAME" macro,
 which is now the recommended name to use in MRO linearisations ("HvNAME"
 being a fallback if there is no "HvENAME").

 These names are added and deleted via "hv_ename_add" and
 "hv_ename_delete".  These two functions are _n_o_t part of the API.

 _N_e_w _f_u_n_c_t_i_o_n_s _f_o_r _f_i_n_d_i_n_g _a_n_d _r_e_m_o_v_i_n_g _m_a_g_i_c

 The "mg_findext()" and "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 ssvv__mmaaggiicceexxtt(()) 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 "MAGIC" pointers of an "SV" to find the magic that
 belongs to them.

 _"_f_i_n_d___r_u_n_d_e_f_s_v_"

 This function returns the SV representing $_, whether it's lexical or
 dynamic.

 _"_P_e_r_l___c_r_o_a_k___n_o___m_o_d_i_f_y_"

 PPeerrll__ccrrooaakk__nnoo__mmooddiiffyy(()) is short-hand for "Perl_croak("%s",
 PL_no_modify)".

 _"_P_E_R_L___S_T_A_T_I_C___I_N_L_I_N_E_" _d_e_f_i_n_e

 The "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
 "static".

 "HAS_STATIC_INLINE" can be used to check if the compiler actually
 supports inline functions.

 _N_e_w _"_p_v___e_s_c_a_p_e_" _o_p_t_i_o_n _f_o_r _h_e_x_a_d_e_c_i_m_a_l _e_s_c_a_p_e_s

 A new option, "PERL_PV_ESCAPE_NONASCII", has been added to "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.

 _"_l_e_x___s_t_a_r_t_"

 "lex_start" has been added to the API, but is considered experimental.

 _oo_pp____ss_cc_oo_pp_ee_((_)) _a_n_d _oo_pp____ll_vv_aa_ll_uu_ee_((_))

 The oopp__ssccooppee(()) and oopp__llvvaalluuee(()) functions have been added to the API, but
 are considered experimental.

CC AAPPII CChhaannggeess _"_P_E_R_L___P_O_L_L_U_T_E_" _h_a_s _b_e_e_n _r_e_m_o_v_e_d

 The option to define "PERL_POLLUTE" to expose older 5.005 symbols for
 backwards compatibility has been removed.  Its use was always
 discouraged, and MakeMaker contains a more specific escape hatch:

     perl Makefile.PL POLLUTE=1

 This can be used for modules that have not been upgraded to 5.6 naming
 conventions (and really should be completely obsolete by now).

 _C_h_e_c_k _A_P_I _c_o_m_p_a_t_i_b_i_l_i_t_y _w_h_e_n _l_o_a_d_i_n_g _X_S _m_o_d_u_l_e_s

 When Perl's API changes in incompatible ways (which usually happens
 between major releases), XS modules compiled for previous versions of
 Perl will no longer work.  They need to be recompiled against the new
 Perl.

 The "XS_APIVERSION_BOOTCHECK" macro has been added to ensure that modules
 are recompiled and to prevent users from accidentally loading modules
 compiled for old perls into newer perls.  That macro, which is called
 when loading every newly compiled extension, compares the API version of
 the running perl with the version a module has been compiled for and
 raises an exception if they don't match.

 _P_e_r_l___f_e_t_c_h___c_o_p___l_a_b_e_l

 The first argument of the C API function "Perl_fetch_cop_label" has
 changed from "struct refcounted_he *" to "COP *", to insulate the user
 from implementation details.

 This API function was marked as "may change", and likely isn't in use
 outside the core.  (Neither an unpacked CPAN nor Google's codesearch
 finds any other references to it.)

 _GG_vv_CC_VV_((_)) _a_n_d _GG_vv_GG_PP_((_)) _a_r_e _n_o _l_o_n_g_e_r _l_v_a_l_u_e_s

 The new GGvvCCVV__sseett(()) and GGvvGGPP__sseett(()) macros are now provided to replace
 assignment to those two macros.

 This allows a future commit to eliminate some backref magic between GV
 and CVs, which will require complete control over assignment to the
 "gp_cv" slot.

 _CC_vv_GG_VV_((_)) _i_s _n_o _l_o_n_g_e_r _a_n _l_v_a_l_u_e

 Under some circumstances, the CCvvGGVV(()) field of a CV is now reference-
 counted.  To ensure consistent behaviour, direct assignment to it, for
 example "CvGV(cv) = gv" is now a compile-time error.  A new macro,
 "CvGV_set(cv,gv)" has been introduced to run this operation safely.  Note
 that modification of this field is not part of the public API, regardless
 of this new macro (and despite its being listed in this section).

 _CC_vv_SS_TT_AA_SS_HH_((_)) _i_s _n_o _l_o_n_g_e_r _a_n _l_v_a_l_u_e

 The CCvvSSTTAASSHH(()) macro can now only be used as an rvalue.  CCvvSSTTAASSHH__sseett(()) has
 been added to replace assignment to CCvvSSTTAASSHH(()).  This is to ensure that
 backreferences are handled properly.  These macros are not part of the

API. #

 _C_a_l_l_i_n_g _c_o_n_v_e_n_t_i_o_n_s _f_o_r _"_n_e_w_F_O_R_O_P_" _a_n_d _"_n_e_w_W_H_I_L_E_O_P_"

 The way the parser handles labels has been cleaned up and refactored.  As
 a result, the nneewwFFOORROOPP(()) constructor function no longer takes a parameter
 stating what label is to go in the state op.

 The nneewwWWHHIILLEEOOPP(()) and nneewwFFOORROOPP(()) functions no longer accept a line number
 as a parameter.

 _F_l_a_g_s _p_a_s_s_e_d _t_o _"_u_v_u_n_i___t_o___u_t_f_8___f_l_a_g_s_" _a_n_d _"_u_t_f_8_n___t_o___u_v_u_n_i_"

 Some of the flags parameters to uuvvuunnii__ttoo__uuttff88__ffllaaggss(()) and
 uuttff88nn__ttoo__uuvvuunnii(()) 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
 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 "UNICODE_ALLOW_FDD0",
 "UNICODE_ALLOW_FFFF", "UNICODE_ILLEGAL", and "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 "Non-character code points" in perlunicode.  See also the
 Unicode section under "Selected Bug Fixes".

DDeepprreeccaatteedd CC AAPPIIss “Perl_ptr_table_clear” “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.

 "sv_compile_2op"
     The ssvv__ccoommppiillee__22oopp(()) API function is now deprecated.  Searches
     suggest that nothing on CPAN is using it, so this should have zero
     impact.

     It attempted to provide an API to compile code down to an optree, but
     failed to bind correctly to lexicals in the enclosing scope.  It's
     not possible to fix this problem within the constraints of its
     parameters and return value.

 "find_rundefsvoffset"
     The "find_rundefsvoffset" function has been deprecated.  It appeared
     that its design was insufficient for reliably getting the lexical $_
     at run-time.

     Use the new "find_rundefsv" function or the "UNDERBAR" macro instead.
     They directly return the right SV representing $_, whether it's
     lexical or dynamic.

 "CALL_FPTR" and "CPERLscope"
     Those are left from an old implementation of "MULTIPLICITY" using C++
     objects, which was removed in Perl 5.8.  Nowadays these macros do
     exactly nothing, so they shouldn't be used anymore.

     For compatibility, they are still defined for external "XS" code.
     Only extensions defining "PERL_CORE" must be updated now.

OOtthheerr IInntteerrnnaall CChhaannggeess _S_t_a_c_k _u_n_w_i_n_d_i_n_g

 The protocol for unwinding the C stack at the last stage of a "die" has
 changed how it identifies the target stack frame.  This now uses a
 separate variable "PL_restartjmpenv", where previously it relied on the
 "blk_eval.cur_top_env" pointer in the "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.

 _S_c_o_p_e _s_t_a_c_k _e_n_t_r_i_e_s

 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.

 _M_e_m_o_r_y _a_l_l_o_c_a_t_i_o_n _f_o_r _p_o_i_n_t_e_r _t_a_b_l_e_s

 Memory allocation for pointer tables has been changed.  Previously
 "Perl_ptr_table_store" allocated memory from the same arena system as
 "SV" bodies and "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 "Perl_ptr_table_free" is called.  Additionally, allocation and
 release are both less CPU intensive.

_"_U_N_D_E_R_B_A_R_" #

 The "UNDERBAR" macro now calls "find_rundefsv".  "dUNDERBAR" is now a
 noop but should still be used to ensure past and future compatibility.

 _S_t_r_i_n_g _c_o_m_p_a_r_i_s_o_n _r_o_u_t_i_n_e_s _r_e_n_a_m_e_d

 The "ibcmp_*" functions have been renamed and are now called "foldEQ",
 "foldEQ_locale", and "foldEQ_utf8".  The old names are still available as
 macros.

 _"_c_h_o_p_" _a_n_d _"_c_h_o_m_p_" _i_m_p_l_e_m_e_n_t_a_t_i_o_n_s _m_e_r_g_e_d

 The opcode bodies for "chop" and "chomp" and for "schop" and "schomp"
 have been merged.  The implementation functions PPeerrll__ddoo__cchhoopp(()) and
 PPeerrll__ddoo__cchhoommpp(()), never part of the public API, have been merged and moved
 to a static function in _p_p_._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 "chomp" is passed a _l_i_s_t of values).

SSeelleecctteedd BBuugg FFiixxeess

II//OO #

 •   Perl no longer produces this warning:

         $ perl -we 'open(my $f, ">", \my $x); binmode($f, "scalar")'
         Use of uninitialized value in binmode at -e line 1.

 •   Opening a glob reference via "open($fh, ">", \*glob)" no longer
     causes the glob to be corrupted when the filehandle is printed to.
     This would cause Perl to crash whenever the glob's contents were
     accessed [perl #77492].

 •   PerlIO no longer crashes when called recursively, such as from a
     signal handler.  Now it just leaks memory [perl #75556].

 •   Most I/O functions were not warning for unopened handles unless the
     "closed" and "unopened" warnings categories were both enabled.  Now
     only "use warnings 'unopened'" is necessary to trigger these
     warnings, as had always been the intention.

 •   There have been several fixes to PerlIO layers:

     When "binmode(FH, ":crlf")" pushes the ":crlf" layer on top of the
     stack, it no longer enables crlf layers lower in the stack so as to
     avoid unexpected results [perl #38456].

     Opening a file in ":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 ":pop", ":utf8", and ":bytes" didn't allow stacking
     when opening a file.  For example this:

         open(FH, ">:pop:perlio", "some.file") or die $!;

     would throw an "Invalid argument" error.  This has been fixed in this
     release [perl #82484].

RReegguullaarr EExxpprreessssiioonn BBuugg FFiixxeess • The regular expression engine no longer loops when matching “"\N{LATIN SMALL LIGATURE FF}” =~ /f+/i" and similar expressions [perl #72998] (5.12.1).

 •   The trie runtime code should no longer allocate massive amounts of
     memory, fixing #74484.

 •   Syntax errors in "(?{...})" blocks no longer cause panic messages
     [perl #2353].

 •   A pattern like "(?:(o){2})?" no longer causes a "panic" error [perl
     #39233].

 •   A fatal error in regular expressions containing "(.*?)" when
     processing UTF-8 data has been fixed [perl #75680] (5.12.2).

 •   An erroneous regular expression engine optimisation that caused regex
     verbs like *COMMIT sometimes to be ignored has been removed.

 •   The regular expression bracketed character class "[\8\9]" was
     effectively the same as "[89\000]", incorrectly matching a NULL
     character.  It also gave incorrect warnings that the 8 and 9 were
     ignored.  Now "[\8\9]" is the same as "[89]" and gives legitimate
     warnings that "\8" and "\9" are unrecognized escape sequences,
     passed-through.

 •   A regular expression match in the right-hand side of a global
     substitution ("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 "s|(.)|@a{ print($1), /./ }|g" [perl
     #19078].

 •   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 "\w" and "\W" [perl #78464] [perl #18281]
     [perl #60156].

 •   Matching a Unicode character against an alternation containing
     characters that happened to match continuation bytes in the former's
     UTF8 representation (like "qq{\x{30ab}} =~ /\xab|\xa9/") would cause
     erroneous warnings [perl #70998].

 •   The trie optimisation was not taking empty groups into account,
     preventing "foo" from matching "/\A(?:(?:)foo|bar|zot)\z/" [perl
     #78356].

 •   A pattern containing a "+" inside a lookahead would sometimes cause
     an incorrect match failure in a global match (for example,
     "/(?=(\S+))/g") [perl #68564].

 •   A regular expression optimisation would sometimes cause a match with
     a "{n,m}" quantifier to fail when it should have matched [perl
     #79152].

 •   Case-insensitive matching in regular expressions compiled under "use
     locale" now works much more sanely when the pattern or target string
     is internally encoded in UTF8.  Previously, under these conditions
     the localeness was completely lost.  Now, code points above 255 are
     treated as Unicode, but code points between 0 and 255 are treated
     using the current locale rules, regardless of whether the pattern or
     the string is encoded in UTF8.  The few case-insensitive matches that
     cross the 255/256 boundary are not allowed.  For example, 0xFF does
     not caselessly match the character at 0x178, LATIN CAPITAL LETTER Y
     WITH DIAERESIS, because 0xFF may not be LATIN SMALL LETTER Y in the
     current locale, and Perl has no way of knowing if that character even
     exists in the locale, much less what code point it is.

 •   The "(?|...)" 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].

 •   A bug has been fixed in the implementation of "{...}" quantifiers in
     regular expressions that prevented the code block in "/((\w+)(?{
     print $2 })){2}/" from seeing the $2 sometimes [perl #84294].

SSyynnttaaxx//PPaarrssiinngg BBuuggss • “when (scalar) {…}” no longer crashes, but produces a syntax error [perl #74114] (5.12.1).

 •   A label right before a string eval ("foo: eval $string") no longer
     causes the label to be associated also with the first statement
     inside the eval [perl #74290] (5.12.1).

 •   The "no 5.13.2" form of "no" no longer tries to turn on features or
     pragmata (like strict) [perl #70075] (5.12.2).

 •   "BEGIN {require 5.12.0}" now behaves as documented, rather than
     behaving identically to "use 5.12.0".  Previously, "require" in a
     "BEGIN" block was erroneously executing the "use feature ':5.12.0'"
     and "use strict" behaviour, which only "use" was documented to
     provide [perl #69050].

 •   A regression introduced in Perl 5.12.0, making "my $x = 3; $x =
     length(undef)" result in $x set to 3 has been fixed.  $x will now be
     "undef" [perl #85508] (5.12.2).

 •   When strict "refs" mode is off, "%{...}" in rvalue context returns
     "undef" if its argument is undefined.  An optimisation introduced in
     Perl 5.12.0 to make "keys %{...}" faster when used as a boolean did
     not take this into account, causing "keys %{+undef}" (and "keys
     %$foo" when $foo is undefined) to be an error, which it should be so
     in strict mode only [perl #81750].

 •   Constant-folding used to cause

       $text =~ ( 1 ? /phoo/ : /bear/)

     to turn into

       $text =~ /phoo/

     at compile time.  Now it correctly matches against $_ [perl #20444].

 •   Parsing Perl code (either with string "eval" or by loading modules)
     from within a "UNITCHECK" block no longer causes the interpreter to
     crash [perl #70614].

 •   String "eval"s no longer fail after 2 billion scopes have been
     compiled [perl #83364].

 •   The parser no longer hangs when encountering certain Unicode
     characters, such as U+387 [perl #74022].

 •   Defining a constant with the same name as one of Perl's special
     blocks (like "INIT") stopped working in 5.12.0, but has now been
     fixed [perl #78634].

 •   A reference to a literal value used as a hash key ($hash{\"foo"})
     used to be stringified, even if the hash was tied [perl #79178].

 •   A closure containing an "if" statement followed by a constant or
     variable is no longer treated as a constant [perl #63540].

 •   "state" can now be used with attributes.  It used to mean the same
     thing as "my" if any attributes were present [perl #68658].

 •   Expressions like "@$a > 3" no longer cause $a to be mentioned in the
     "Use of uninitialized value in numeric gt" warning when $a is
     undefined (since it is not part of the ">" expression, but the
     operand of the "@") [perl #72090].

 •   Accessing an element of a package array with a hard-coded number (as
     opposed to an arbitrary expression) would crash if the array did not
     exist.  Usually the array would be autovivified during compilation,
     but typeglob manipulation could remove it, as in these two cases
     which used to crash:

       *d = *a;  print $d[0];
       undef *d; print $d[0];

 •   The --CC command-line option, when used on the shebang line, can now be
     followed by other options [perl #72434].

 •   The "B" module was returning "B::OP"s instead of "B::LOGOP"s for
     "entertry" [perl #80622].  This was due to a bug in the Perl core,
     not in "B" itself.

SSttaasshheess,, GGlloobbss aanndd MMeetthhoodd LLooookkuupp 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:

 •   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.

     Aliasing packages by assigning to globs [perl #77358]
     Deleting packages by deleting their containing stash elements
     Undefining the glob containing a package ("undef *Foo::")
     Undefining an ISA glob ("undef *Foo::ISA")
     Deleting an ISA stash element ("delete $Foo::{ISA}")
     Sharing @ISA arrays between classes (via "*Foo::ISA = \@Bar::ISA" or
     "*Foo::ISA = *Bar::ISA") [perl #77238]

     "undef *Foo::ISA" would even stop a new @Foo::ISA array from updating
     caches.

 •   Typeglob assignments would crash if the glob's stash no longer
     existed, so long as the glob assigned to were named "ISA" or the glob
     on either side of the assignment contained a subroutine.

 •   "PL_isarev", which is accessible to Perl via "mro::get_isarev" is now
     updated properly when packages are deleted or removed from the @ISA
     of other classes.  This allows many packages to be created and
     deleted without causing a memory leak [perl #75176].

 In addition, various other bugs related to typeglobs and stashes have
 been fixed:

 •   Some work has been done on the internal pointers that link between
     symbol tables (stashes), typeglobs, and subroutines.  This has the
     effect that various edge cases related to deleting stashes or stash
     entries (for example, <%FOO:: = ()>), and complex typeglob or code-
     reference aliasing, will no longer crash the interpreter.

 •   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].

 •   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;
         }

 •   Assigning a glob to a PVLV used to convert it to a plain string.  Now
     it works correctly, and a PVLV can hold a glob.  This would happen
     when a nonexistent hash or array element was passed to a subroutine:

       sub { $_[0] = *foo }->($hash{key});
       # $_[0] would have been the string "*main::foo"

     It also happened when a glob was assigned to, or returned from, an
     element of a tied array or hash [perl #36051].

 •   When trying to report "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, "delete
     $::{"Foo::"}".  This has been fixed by disabling the reporting of
     variable names in those cases.

 •   During the restoration of a localised typeglob on scope exit, any
     destructors called as a result would be able to see the typeglob in
     an inconsistent state, containing freed entries, which could result
     in a crash.  This would affect code like this:

       local *@;
       eval { die bless [] }; # puts an object in $@
       sub DESTROY {
         local $@; # boom
       }

     Now the glob entries are cleared before any destructors are called.
     This also means that destructors can vivify entries in the glob.  So
     Perl tries again and, if the entries are re-created too many times,
     dies with a "panic: gp_free ..." error message.

 •   If a typeglob is freed while a subroutine attached to it is still
     referenced elsewhere, the subroutine is renamed to "__ANON__" in the
     same package, unless the package has been undefined, in which case
     the "__ANON__" package is used.  This could cause packages to be
     sometimes autovivified, such as if the package had been deleted.  Now
     this no longer occurs.  The "__ANON__" package is also now used when
     the original package is no longer attached to the symbol table.  This
     avoids memory leaks in some cases [perl #87664].

 •   Subroutines and package variables inside a package whose name ends
     with "::" can now be accessed with a fully qualified name.

UUnniiccooddee • What has become known as “the Unicode Bug” is almost completely resolved in this release. Under “use feature ‘unicode_strings’” (which is automatically selected by “use 5.012” and above), the internal storage format of a string no longer affects the external semantics. [perl #58182].

     There are two known exceptions:

     1.  The now-deprecated, user-defined case-changing functions require
         utf8-encoded strings to operate.  The CPAN module Unicode::Casing
         has been written to replace this feature without its drawbacks,
         and the feature is scheduled to be removed in 5.16.

     2.  qquuootteemmeettaa(()) (and its in-line equivalent "\Q") can also give
         different results depending on whether a string is encoded in
         UTF-8.  See "The "Unicode Bug"" in perlunicode.

 •   Handling of Unicode non-character code points has changed.
     Previously they were mostly considered illegal, except that in some
     place only one of the 66 of them was known.  The Unicode Standard
     considers them all legal, but forbids their "open interchange".  This
     is part of the change to allow internal use of any code point (see
     "Core Enhancements").  Together, these changes resolve [perl #38722],
     [perl #51918], [perl #51936], and [perl #63446].

 •   Case-insensitive "/i" regular expression matching of Unicode
     characters that match multiple characters now works much more as
     intended.  For example

      "\N{LATIN SMALL LIGATURE FFI}" =~ /ffi/ui

     and

      "ffi" =~ /\N{LATIN SMALL LIGATURE FFI}/ui

     are both true.  Previously, there were many bugs with this feature.
     What hasn't been fixed are the places where the pattern contains the
     multiple characters, but the characters are split up by other things,
     such as in

      "\N{LATIN SMALL LIGATURE FFI}" =~ /(f)(f)i/ui

     or

      "\N{LATIN SMALL LIGATURE FFI}" =~ /ffi*/ui

     or

      "\N{LATIN SMALL LIGATURE FFI}" =~ /[a-f][f-m][g-z]/ui

     None of these match.

     Also, this matching doesn't fully conform to the current Unicode
     Standard, which asks that the matching be made upon the NFD
     (Normalization Form Decomposed) of the text.  However, as of this
     writing (April 2010), the Unicode Standard is currently in flux about
     what they will recommend doing with regard in such scenarios.  It may
     be that they will throw out the whole concept of multi-character
     matches.  [perl #71736].

 •   Naming a deprecated character in "\N{_N_A_M_E}" no longer leaks memory.

 •   We fixed a bug that could cause "\N{_N_A_M_E}" constructs followed by a
     single "." to be parsed incorrectly [perl #74978] (5.12.1).

 •   "chop" now correctly handles characters above "\x{7fffffff}" [perl
     #73246].

 •   Passing to "index" an offset beyond the end of the string when the
     string is encoded internally in UTF8 no longer causes panics [perl
     #75898].

 •   wwaarrnn(()) and ddiiee(()) now respect utf8-encoded scalars [perl #45549].

 •   Sometimes the UTF8 length cache would not be reset on a value
     returned by substr, causing "length(substr($uni_string, ...))" to
     give wrong answers.  With "${^UTF8CACHE}" set to -1, it would also
     produce a "panic" error message [perl #77692].

TTiieess,, OOvveerrllooaaddiinngg aanndd OOtthheerr MMaaggiicc • Overloading now works properly in conjunction with tied variables. What formerly happened was that most ops checked their arguments for overloading _b_e_f_o_r_e checking for magic, so for example an overloaded object returned by a tied array access would usually be treated as not overloaded [RT #57012].

 •   Various instances of magic (like tie methods) being called on tied
     variables too many or too few times have been fixed:

     •   "$tied->()" did not always call FETCH [perl #8438].

     •   Filetest operators and "y///" and "tr///" were calling FETCH too
         many times.

     •   The "=" 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].

     •   Dereference operators used to ignore magic if the argument was a
         reference already (such as from a previous FETCH) [perl #72144].

     •   "splice" now calls set-magic (so changes made by "splice @ISA"
         are respected by method calls) [perl #78400].

     •   In-memory files created by "open($fh, ">", \$buffer)" were not
         calling FETCH/STORE at all [perl #43789] (5.12.2).

     •   uuttff88::::iiss__uuttff88(()) now respects get-magic (like $1) (5.12.1).

 •   Non-commutative binary operators used to swap their operands if the
     same tied scalar was used for both operands and returned a different
     value for each FETCH.  For instance, if $t returned 2 the first time
     and 3 the second, then "$t/$t" would evaluate to 1.5.  This has been
     fixed [perl #87708].

 •   String "eval" now detects taintedness of overloaded or tied arguments
     [perl #75716].

 •   String "eval" and regular expression matches against objects with
     string overloading no longer cause memory corruption or crashes [perl
     #77084].

 •   readline now honors "<>" overloading on tied arguments.

 •   "<expr>" always respects overloading now if the expression is
     overloaded.

     Because "<> as glob" was parsed differently from "<> as filehandle"
     from 5.6 onwards, something like "<$foo[0]>" did not handle
     overloading, even if $foo[0] was an overloaded object.  This was
     contrary to the documentation for overload, and meant that "<>" could
     not be used as a general overloaded iterator operator.

 •   The fallback behaviour of overloading on binary operators was
     asymmetric [perl #71286].

 •   Magic applied to variables in the main package no longer affects
     other packages.  See "Magic variables outside the main package" above
     [perl #76138].

 •   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].

 •   DESTROY methods of objects implementing ties are no longer able to
     crash by accessing the tied variable through a weak reference [perl
     #86328].

 •   Fixed a regression of kkiillll(()) when a match variable is used for the
     process ID to kill [perl #75812].

 •   $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.

 •   "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].

 •   "lc", "uc", "lcfirst", and "ucfirst" no longer return untainted
     strings when the argument is tainted.  This has been broken since
     perl 5.8.9 [perl #87336].

TThhee DDeebbuuggggeerr • The Perl debugger now also works in taint mode [perl #76872].

 •   Subroutine redefinition works once more in the debugger [perl
     #48332].

 •   When --dd is used on the shebang ("#!") line, the debugger now has
     access to the lines of the main program.  In the past, this sometimes
     worked and sometimes did not, depending on the order in which things
     happened to be arranged in memory [perl #71806].

 •   A possible memory leak when using ccaalllleerr(()) to set @DB::args has been
     fixed (5.12.2).

 •   Perl no longer stomps on $DB::single, $DB::trace, and $DB::signal if
     these variables already have values when $^P is assigned to [perl
     #72422].

 •   "#line" directives in string evals were not properly updating the
     arrays of lines of code ("@{"_< ..."}") 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].

TThhrreeaaddss • Perl no longer accidentally clones lexicals in scope within active stack frames in the parent when creating a child thread [perl #73086].

 •   Several memory leaks in cloning and freeing threaded Perl
     interpreters have been fixed [perl #77352].

 •   Creating a new thread when directory handles were open used to cause
     a crash, because the handles were not cloned, but simply passed to
     the new thread, resulting in a double free.

     Now directory handles are cloned properly on Windows and on systems
     that have a "fchdir" function.  On other systems, new threads simply
     do not inherit directory handles from their parent threads [perl
     #75154].

 •   The typeglob "*,", which holds the scalar variable $, (output field
     separator), had the wrong reference count in child threads.

 •   [perl #78494] When pipes are shared between threads, the "close"
     function (and any implicit close, such as on thread exit) no longer
     blocks.

 •   Perl now does a timely cleanup of SVs that are cloned into a new
     thread but then discovered to be orphaned (that is, their owners are
     _n_o_t cloned).  This eliminates several "scalars leaked" warnings when
     joining threads.

SSccooppiinngg aanndd SSuubbrroouuttiinneess • 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).

 •   "require" no longer causes "caller" to return the wrong file name for
     the scope that called "require" and other scopes higher up that had
     the same file name [perl #68712].

 •   "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].

 •   Match variables (like $1) no longer persist between calls to a sort
     subroutine [perl #76026].

 •   Iterating with "foreach" over an array returned by an lvalue sub now
     works [perl #23790].

 •   $@ is now localised during calls to "binmode" to prevent action at a
     distance [perl #78844].

 •   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].

 •   Mentioning a read-only lexical variable from the enclosing scope in a
     string "eval" no longer causes the variable to become writable [perl
     #19135].

SSiiggnnaallss • Within signal handlers, $! is now implicitly localized.

 •   CHLD signals are no longer unblocked after a signal handler is called
     if they were blocked before by "POSIX::sigprocmask" [perl #82040].

 •   A signal handler called within a signal handler could cause leaks or
     double-frees.  Now fixed [perl #76248].

MMiisscceellllaanneeoouuss MMeemmoorryy LLeeaakkss • Several memory leaks when loading XS modules were fixed (5.12.2).

 •   ssuubbssttrr(()), ppooss(()), kkeeyyss(()), and vveecc(()) 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.

 •   The postincrement and postdecrement operators, "++" and "--", used to
     cause leaks when used on references.  This has now been fixed.

 •   Nested "map" and "grep" blocks no longer leak memory when processing
     large lists [perl #48004].

 •   "use _V_E_R_S_I_O_N" and "no _V_E_R_S_I_O_N" no longer leak memory [perl #78436]
     [perl #69050].

 •   ".=" followed by "<>" or "readline" would leak memory if $/ contained
     characters beyond the octet range and the scalar assigned to happened
     to be encoded as UTF8 internally [perl #72246].

 •   "eval 'BEGIN{die}'" no longer leaks memory on non-threaded builds.

MMeemmoorryy CCoorrrruuppttiioonn aanndd CCrraasshheess • gglloobb(()) no longer crashes when %File::Glob:: is empty and “CORE::GLOBAL::glob” isn’t present [perl #75464] (5.12.2).

 •   rreeaaddlliinnee(()) has been fixed when interrupted by signals so it no longer
     returns the "same thing" as before or random memory.

 •   When assigning a list with duplicated keys to a hash, the assignment
     used to return garbage and/or freed values:

         @a = %h = (list with some duplicate keys);

     This has now been fixed [perl #31865].

 •   The mechanism for freeing objects in globs used to leave dangling
     pointers to freed SVs, meaning Perl users could see corrupted state
     during destruction.

     Perl now frees only the affected slots of the GV, rather than freeing
     the GV itself.  This makes sure that there are no dangling refs or
     corrupted state during destruction.

 •   The interpreter no longer crashes when freeing deeply-nested arrays
     of arrays.  Hashes have not been fixed yet [perl #44225].

 •   Concatenating long strings under "use encoding" no longer causes Perl
     to crash [perl #78674].

 •   Calling "->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 $b [perl #63790].

 •   The "recv" function could crash when called with the MSG_TRUNC flag
     [perl #75082].

 •   "formline" no longer crashes when passed a tainted format picture.
     It also taints $^A now if its arguments are tainted [perl #79138].

 •   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).

 •   uunnppaacckk(()) now handles scalar context correctly for %32H and %32u,
     fixing a potential crash.  sspplliitt(()) would crash because the third item
     on the stack wasn't the regular expression it expected.
     "unpack("%2H", ...)" would return both the unpacked result and the
     checksum on the stack, as would "unpack("%2u", ...)" [perl #73814]
     (5.12.2).

FFiixxeess ttoo VVaarriioouuss PPeerrll OOppeerraattoorrss • The “&”, “|”, and “^” bitwise operators no longer coerce read-only arguments [perl #20661].

 •   Stringifying a scalar containing "-0.0" no longer has the effect of
     turning false into true [perl #45133].

 •   Some numeric operators were converting integers to floating point,
     resulting in loss of precision on 64-bit platforms [perl #77456].

 •   sspprriinnttff(()) was ignoring locales when called with constant arguments
     [perl #78632].

 •   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].

BBuuggss RReellaattiinngg ttoo tthhee CC AAPPII • The C-level “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).

 •   The "eval_sv" and "eval_pv" C functions now set $@ correctly when
     there is a syntax error and no "G_KEEPERR" flag, and never set it if
     the "G_KEEPERR" flag is present [perl #3719].

 •   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].

 •   The "SvPVbyte" function available to XS modules now calls magic
     before downgrading the SV, to avoid warnings about wide characters
     [perl #72398].

 •   The ref types in the typemap for XS bindings now support magical
     variables [perl #72684].

 •   "sv_catsv_flags" no longer calls "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.

 •   "my_strftime" no longer leaks memory.  This fixes a memory leak in
     "POSIX::strftime" [perl #73520].

 •   _X_S_U_B_._h now correctly redefines fgets under PERL_IMPLICIT_SYS [perl
     #55049] (5.12.1).

 •   XS code using ffppuuttcc(()) or ffppuuttss(()) on Windows could cause an error due
     to their arguments being swapped [perl #72704] (5.12.1).

 •   A possible segfault in the "T_PTROBJ" default typemap has been fixed
     (5.12.2).

 •   A bug that could cause "Unknown error" messages when "call_sv(code,
     G_EVAL)" is called from an XS destructor has been fixed (5.12.2).

KKnnoowwnn PPrroobblleemmss This is a list of significant unresolved issues which are regressions from earlier versions of Perl or which affect widely-used CPAN modules.

 •   "List::Util::first" misbehaves in the presence of a lexical $_
     (typically introduced by "my $_" or implicitly by "given").  The
     variable that gets set for each iteration is the package variable $_,
     not the lexical $_.

     A similar issue may occur in other modules that provide functions
     which take a block as their first argument, like

         foo { ... $_ ...} list

     See also: <https://github.com/Perl/perl5/issues/9798>

 •   rreeaaddlliinnee(()) returns an empty string instead of a cached previous value
     when it is interrupted by a signal

 •   The changes in prototype handling break Switch.  A patch has been
     sent upstream and will hopefully appear on CPAN soon.

 •   The upgrade to _E_x_t_U_t_i_l_s_-_M_a_k_e_M_a_k_e_r_-_6_._5_7___0_5 has caused some tests in
     the _M_o_d_u_l_e_-_I_n_s_t_a_l_l distribution on CPAN to fail. (Specifically,
     _0_2___m_y_m_e_t_a_._t tests 5 and 21; _1_8___a_l_l___f_r_o_m_._t tests 6 and 15;
     _1_9___a_u_t_h_o_r_s_._t tests 5, 13, 21, and 29; and
     _2_0___a_u_t_h_o_r_s___w_i_t_h___s_p_e_c_i_a_l___c_h_a_r_a_c_t_e_r_s_._t tests 6, 15, and 23 in version
     1.00 of that distribution now fail.)

 •   On VMS, "Time::HiRes" tests will fail due to a bug in the CRTL's
     implementation of "setitimer": previous timer values would be cleared
     if a timer expired but not if the timer was reset before expiring.
     HP OpenVMS Engineering have corrected the problem and will release a
     patch in due course (Quix case # QXCM1001115136).

 •   On VMS, there were a handful of "Module::Build" test failures we
     didn't get to before the release; please watch CPAN for updates.

EErrrraattaa kkeeyyss(()),, vvaalluueess(()),, aanndd eeaacchh(()) wwoorrkk oonn aarrrraayyss You can now use the kkeeyyss(()), vvaalluueess(()), and eeaacchh(()) builtins on arrays; previously you could use them only on hashes. See perlfunc for details. This is actually a change introduced in perl 5.12.0, but it was missed from that release’s perl5120delta.

sspplliitt(()) aanndd @@ sspplliitt(()) no longer modifies @_ when called in scalar or void context. In void context it now produces a “Useless use of split” warning. This was also a perl 5.12.0 change that missed the perldelta.

OObbiittuuaarryy Randy Kobes, creator of http://kobesearch.cpan.org/ and contributor/maintainer to several core Perl toolchain modules, passed away on September 18, 2010 after a battle with lung cancer. The community was richer for his involvement. He will be missed.

AAcckknnoowwlleeddggeemmeennttss Perl 5.14.0 represents one year of development since Perl 5.12.0 and contains nearly 550,000 lines of changes across nearly 3,000 files from 150 authors and committers.

 Perl continues to flourish into its third decade thanks to a vibrant
 community of users and developers.  The following people are known to
 have contributed the improvements that became Perl 5.14.0:

 Aaron Crane, Abhijit Menon-Sen, Abigail, Ævar Arnfjörð Bjarmason,
 Alastair Douglas, Alexander Alekseev, Alexander Hartmaier, Alexandr
 Ciornii, Alex Davies, Alex Vandiver, Ali Polatel, Allen Smith, Andreas
 König, Andrew Rodland, Andy Armstrong, Andy Dougherty, Aristotle
 Pagaltzis, Arkturuz, Arvan, A. Sinan Unur, Ben Morrow, Bo Lindbergh,
 Boris Ratner, Brad Gilbert, Bram, brian d foy, Brian Phillips, Casey
 West, Charles Bailey, Chas. Owens, Chip Salzenberg, Chris 'BinGOs'
 Williams, chromatic, Craig A. Berry, Curtis Jewell, Dagfinn Ilmari
 Mannsåker, Dan Dascalescu, Dave Rolsky, David Caldwell, David Cantrell,
 David Golden, David Leadbeater, David Mitchell, David Wheeler, Eric
 Brine, Father Chrysostomos, Fingle Nark, Florian Ragwitz, Frank Wiegand,
 Franz Fasching, Gene Sullivan, George Greer, Gerard Goossen, Gisle Aas,
 Goro Fuji, Grant McLean, gregor herrmann, H.Merijn Brand, Hongwen Qiu,
 Hugo van der Sanden, Ian Goodacre, James E Keenan, James Mastros, Jan
 Dubois, Jay Hannah, Jerry D. Hedden, Jesse Vincent, Jim Cromie, Jirka
 Hruška, John Peacock, Joshua ben Jore, Joshua Pritikin, Karl Williamson,
 Kevin Ryde, kmx, Lars Dɪᴇᴄᴋᴏᴡ 迪拉斯, Larwan Berke, Leon Brocard, Leon
 Timmermans, Lubomir Rintel, Lukas Mai, Maik Hentsche, Marty Pauley,
 Marvin Humphrey, Matt Johnson, Matt S Trout, Max Maischein, Michael
 Breen, Michael Fig, Michael G Schwern, Michael Parker, Michael Stevens,
 Michael Witten, Mike Kelly, Moritz Lenz, Nicholas Clark, Nick Cleaton,
 Nick Johnston, Nicolas Kaiser, Niko Tyni, Noirin Shirley, Nuno Carvalho,
 Paul Evans, Paul Green, Paul Johnson, Paul Marquess, Peter J. Holzer,
 Peter John Acklam, Peter Martini, Philippe Bruhat (BooK), Piotr Fusik,
 Rafael Garcia-Suarez, Rainer Tammer, Reini Urban, Renee Baecker, Ricardo
 Signes, Richard Möhn, Richard Soderberg, Rob Hoelz, Robin Barker, Ruslan
 Zakirov, Salvador Fandiño, Salvador Ortiz Garcia, Shlomi Fish, Sinan
 Unur, Sisyphus, Slaven Rezic, Steffen Müller, Steve Hay, Steven
 Schubiger, Steve Peters, Sullivan Beck, Tatsuhiko Miyagawa, Tim Bunce,
 Todd Rinaldo, Tom Christiansen, Tom Hukins, Tony Cook, Tye McQueen, Vadim
 Konovalov, Vernon Lyon, Vincent Pit, Walt Mankowski, Wolfram Humann, Yves
 Orton, Zefram, and Zsbán Ambrus.

 This is woefully incomplete as it's automatically generated from version
 control history.  In particular, it doesn't include the names of the
 (very much appreciated) contributors who reported issues in previous
 versions of Perl that helped make Perl 5.14.0 better. For a more complete
 list of all of Perl's historical contributors, please see the "AUTHORS"
 file in the Perl 5.14.0 distribution.

 Many of the changes included in this version originated in the CPAN
 modules included in Perl's core. We're grateful to the entire CPAN
 community for helping Perl to flourish.

RReeppoorrttiinngg BBuuggss If you find what you think is a bug, you might check the articles recently posted to the comp.lang.perl.misc newsgroup and the Perl bug database at http://rt.perl.org/perlbug/ . There may also be information at http://www.perl.org/ , the Perl Home Page.

 If you believe you have an unreported bug, please run the perlbug program
 included with your release.  Be sure to trim your bug down to a tiny but
 sufficient test case.  Your bug report, along with the output of "perl
 -V", will be sent off to perlbug@perl.org to be analysed by the Perl
 porting team.

 If the bug you are reporting has security implications, which make it
 inappropriate to send to a publicly archived mailing list, then please
 send it to perl5-security-report@perl.org.  This points to a closed
 subscription unarchived mailing list, which includes all the core
 committers, who 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
 use this address for security issues in the Perl core _o_n_l_y, not for
 modules independently distributed on CPAN.

SSEEEE AALLSSOO #

 The _C_h_a_n_g_e_s file for an explanation of how to view exhaustive details on
 what changed.

 The _I_N_S_T_A_L_L file for how to build Perl.

 The _R_E_A_D_M_E file for general stuff.

 The _A_r_t_i_s_t_i_c and _C_o_p_y_i_n_g files for copyright information.

perl v5.36.3 2023-02-15 PERL5140DELTA(1)