perl589delta


DESCRIPTION
       This document describes differences between the 5.8.8 release and the
       5.8.9 release.

Notice
       The 5.8.9 release will be the last significant release of the 5.8.x
       series. Any future releases of 5.8.x will likely only be to deal with
       security issues, and platform build failures. Hence you should look to
       migrating to 5.10.x, if you have not started already.  See "Known
       Problems" for more information.

Incompatible Changes
       A particular construction in the source code of extensions written in
       C++ may need changing. See "Changed Internals" for more details. All
       extensions written in C, most written in C++, and all existing compiled
       extensions are unaffected. This was necessary to improve C++ support.

       Other than this, there are no changes intentionally incompatible with
       5.8.8.  If any exist, they are bugs and reports are welcome.

Core Enhancements
   Unicode Character Database 5.1.0.
       The copy of the Unicode Character Database included in Perl 5.8 has
       been updated to 5.1.0 from 4.1.0. See
       <http://www.unicode.org/versions/Unicode5.1.0/#NotableChanges> for the
       notable changes.

   stat and -X on directory handles
       It is now possible to call "stat" and the "-X" filestat operators on
       directory handles. As both directory and file handles are barewords,
       there can be ambiguities over which was intended. In these situations
       the file handle semantics are preferred. Both also treat *FILE{IO}
       filehandles like *FILE filehandles.

   Source filters in @INC
       It's possible to enhance the mechanism of subroutine hooks in @INC by
       adding a source filter on top of the filehandle opened and returned by
       the hook. This feature was planned a long time ago, but wasn't quite
       working until now. See "require" in perlfunc for details. (Nicholas
       Clark)

   Exceptions in constant folding
       The constant folding routine is now wrapped in an exception handler,
       and if folding throws an exception (such as attempting to evaluate
       0/0), perl now retains the current optree, rather than aborting the
       whole program.  Without this change, programs would not compile if they
       had expressions that happened to generate exceptions, even though those
       expressions were in code that could never be reached at runtime.
       (Nicholas Clark, Dave Mitchell)

   "no VERSION"
       You can now use "no" followed by a version number to specify that you
       want to use a version of perl older than the specified one.
       There is now Configure support for creating a perl tree that is
       relocatable at run time. see "Relocatable installations".

   New internal variables
       "${^CHILD_ERROR_NATIVE}"
           This variable gives the native status returned by the last pipe
           close, backtick command, successful call to "wait" or "waitpid", or
           from the "system" operator. See perlvar for details. (Contributed
           by Gisle Aas.)

       "${^UTF8CACHE}"
           This variable controls the state of the internal UTF-8 offset
           caching code.  1 for on (the default), 0 for off, -1 to debug the
           caching code by checking all its results against linear scans, and
           panicking on any discrepancy.

   "readpipe" is now overridable
       The built-in function "readpipe" is now overridable. Overriding it
       permits also to override its operator counterpart, "qx//" (also known
       as "``").

   simple exception handling macros
       Perl 5.8.9 (and 5.10.0 onwards) now provides a couple of macros to do
       very basic exception handling in XS modules. You can use these macros
       if you call code that may "croak", but you need to do some cleanup
       before giving control back to Perl. See "Exception Handling" in
       perlguts for more details.

   -D option enhancements
       o   "-Dq" suppresses the EXECUTING... message when running under "-D"

       o   "-Dl" logs runops loop entry and exit, and jump level popping.

       o   "-Dv" displays the process id as part of the trace output.

   XS-assisted SWASHGET
       Some pure-perl code that the regexp engine was using to retrieve
       Unicode properties and transliteration mappings has been reimplemented
       in XS for faster execution.  (SADAHIRO Tomoyuki)

   Constant subroutines
       The interpreter internals now support a far more memory efficient form
       of inlineable constants. Storing a reference to a constant value in a
       symbol table is equivalent to a full typeglob referencing a constant
       subroutine, but using about 400 bytes less memory. This proxy constant
       subroutine is automatically upgraded to a real typeglob with subroutine
       if necessary.  The approach taken is analogous to the existing space
       optimisation for subroutine stub declarations, which are stored as
       plain scalars in place of the full typeglob.

       However, to aid backwards compatibility of existing code, which
       (wrongly) does not expect anything other than typeglobs in symbol
       tables, nothing in core uses this feature, other than the regression
       tests.
       o   MidnightBSD

       o   MirOS BSD

       o   RISC OS

       o   Cray XT4/Catamount

Modules and Pragmata
   New Modules
       o   "Module::Pluggable" is a simple framework to create modules that
           accept pluggable sub-modules. The bundled version is 3.8

       o   "Module::CoreList" is a hash of hashes that is keyed on perl
           version as indicated in $]. The bundled version is 2.17

       o   "Win32API::File" now available in core on Microsoft Windows. The
           bundled version is 0.1001_01

       o   "Devel::InnerPackage" finds all the packages defined by a single
           file. It is part of the "Module::Pluggable" distribution. The
           bundled version is 0.3

   Updated Modules
       o   "attributes" upgraded to version 0.09

       o   "AutoLoader" upgraded to version 5.67

       o   "AutoSplit" upgraded to 1.06

       o   "autouse" upgraded to version 1.06

       o   "B" upgraded from 1.09_01 to 1.19

           o   provides new pad related abstraction macros
               "B::NV::COP_SEQ_RANGE_LOW", "B::NV::COP_SEQ_RANGE_HIGH",
               "B::NV::PARENT_PAD_INDEX", "B::NV::PARENT_FAKELEX_FLAGS", which
               hides the difference in storage in 5.10.0 and later.

           o   provides "B::sub_generation", which exposes "PL_sub_generation"

           o   provides "B::GV::isGV_with_GP", which on pre-5.10 perls always
               returns true.

           o   New type "B::HE" added with methods "VAL", "HASH" and
               "SVKEY_force"

           o   The "B::GVf_IMPORTED_CV" flag is now set correctly when a proxy
               constant subroutine is imported.

           o   bugs fixed in the handling of "PMOP"s.

           o   "B::BM::PREVIOUS" returns now "U32", not "U16".  "B::CV::START"
               and "B:CV::ROOT" return now "NULL" on an XSUB, "B::CV::XSUB"

           o   now has documentation of detailed hint symbols.

       o   "B::Debug" upgraded to version 1.05

       o   "B::Deparse" upgraded to version 0.87

           o   properly deparse "print readpipe $x, $y".

           o   now handles "''-"()>, "::()", "sub :: {}", etc. correctly [RT
               #43010].  All bugs in parsing these kinds of syntax are now
               fixed:

                   perl -MO=Deparse -e '"my %h = "->()'
                   perl -MO=Deparse -e '::->()'
                   perl -MO=Deparse -e 'sub :: {}'
                   perl -MO=Deparse -e 'package a; sub a::b::c {}'
                   perl -MO=Deparse -e 'sub the::main::road {}'

           o   does not deparse $^H{v_string}, which is automatically set by
               the internals.

       o   "B::Lint" upgraded to version 1.11

       o   "B::Terse" upgraded to version 1.05

       o   "base" upgraded to version 2.13

           o   loading a module via base.pm would mask a global $SIG{__DIE__}
               in that module.

           o   push all classes at once in @ISA

       o   "Benchmark" upgraded to version 1.10

       o   "bigint" upgraded to 0.23

       o   "bignum" upgraded to 0.23

       o   "bigrat" upgraded to 0.23

       o   "blib" upgraded to 0.04

       o   "Carp" upgraded to version 1.10

           The argument backtrace code now shows "undef" as "undef", instead
           of a string "undef".

       o   "CGI" upgraded to version 3.42

       o   "charnames" upgraded to 1.06

       o   "constant" upgraded to version 1.17

               such as Win32.

       o   "DB_File" upgraded to version 1.817

       o   "DB_Filter" upgraded to version 0.02

       o   "Devel::DProf" upgraded to version 20080331.00

       o   "Devel::Peek" upgraded to version 1.04

       o   "Devel::PPPort" upgraded to version 3.14

       o   "diagnostics" upgraded to version 1.16

       o   "Digest" upgraded to version 1.15

       o   "Digest::MD5" upgraded to version 2.37

       o   "DirHandle" upgraded to version 1.02

           o   now localises $., $@, $!, $^E, and $? before closing the
               directory handle to suppress leaking any side effects of
               warnings about it already being closed.

       o   "DynaLoader" upgraded to version 1.09

           "DynaLoader" can now dynamically load a loadable object from a file
           with a non-default file extension.

       o   "Encode" upgraded to version 2.26

           "Encode::Alias" includes a fix for encoding "646" on Solaris
           (better known as ASCII).

       o   "English" upgraded to version 1.03

       o   "Errno" upgraded to version 1.10

       o   "Exporter" upgraded to version 5.63

       o   "ExtUtils::Command" upgraded to version 1.15

       o   "ExtUtils::Constant" upgraded to version 0.21

       o   "ExtUtils::Embed" upgraded to version 1.28

       o   "ExtUtils::Install" upgraded to version 1.50_01

       o   "ExtUtils::Installed" upgraded to version 1.43

       o   "ExtUtils::MakeMaker" upgraded to version 6.48

           o   support for "INSTALLSITESCRIPT" and "INSTALLVENDORSCRIPT"
               configuration.

       o   "File::Basename" upgraded to version 2.77

       o   "FileCache" upgraded to version 1.07

       o   "File::Compare" upgraded to 1.1005

       o   "File::Copy" upgraded to 2.13

           o   now uses 3-arg open.

       o   "File::DosGlob" upgraded to 1.01

       o   "File::Find" upgraded to version 1.13

       o   "File::Glob" upgraded to version 1.06

           o   fixes spurious results with brackets inside braces.

       o   "File::Path" upgraded to version 2.07_02

       o   "File::Spec" upgraded to version 3.29

           o   improved handling of bad arguments.

           o   some platform specific improvements (including for VMS and
               Cygwin), with an optimisation on "abs2rel" when handling both
               relative arguments.

       o   "File::stat" upgraded to version 1.01

       o   "File::Temp" upgraded to version 0.20

       o   "filetest" upgraded to version 1.02

       o   "Filter::Util::Call" upgraded to version 1.07

       o   "Filter::Simple" upgraded to version 0.83

       o   "FindBin" upgraded to version 1.49

       o   "GDBM_File" upgraded to version 1.09

       o   "Getopt::Long" upgraded to version 2.37

       o   "Getopt::Std" upgraded to version 1.06

       o   "Hash::Util" upgraded to version 0.06

       o   "if" upgraded to version 0.05

       o   "IO" upgraded to version 1.23

           Reduced number of calls to "getpeername" in "IO::Socket"

       o   "List::Util" upgraded to 1.19

       o   "Locale::Maketext" upgraded to 1.13

       o   "Math::BigFloat" upgraded to version 1.60

       o   "Math::BigInt" upgraded to version 1.89

       o   "Math::BigRat" upgraded to version 0.22

           o   implements new "as_float" method.

       o   "Math::Complex" upgraded to version 1.54.

       o   "Math::Trig" upgraded to version 1.18.

       o   "NDBM_File" upgraded to version 1.07

           o   improve g++ handling for systems using GDBM compatibility
               headers.

       o   "Net::Ping" upgraded to version 2.35

       o   "NEXT" upgraded to version 0.61

           o   fix several bugs with "NEXT" when working with "AUTOLOAD",
               "eval" block, and within overloaded stringification.

       o   "ODBM_File" upgraded to 1.07

       o   "open" upgraded to 1.06

       o   "ops" upgraded to 1.02

       o   "PerlIO::encoding" upgraded to version 0.11

       o   "PerlIO::scalar" upgraded to version 0.06

           o   [RT #40267] "PerlIO::scalar" doesn't respect readonly-ness.

       o   "PerlIO::via" upgraded to version 0.05

       o   "Pod::Html" upgraded to version 1.09

       o   "Pod::Parser" upgraded to version 1.35

       o   "Pod::Usage" upgraded to version 1.35

       o   "POSIX" upgraded to version 1.15

           o   "POSIX" constants that duplicate those in "Fcntl" are now
               imported from "Fcntl" and re-exported, rather than being
               duplicated by "POSIX"

       o   "Scalar::Util" upgraded to 1.19

       o   "SDBM_File" upgraded to version 1.06

       o   "SelfLoader" upgraded to version 1.17

       o   "Shell" upgraded to version 0.72

       o   "sigtrap" upgraded to version 1.04

       o   "Socket" upgraded to version 1.81

           o   this fixes an optimistic use of "gethostbyname"

       o   "Storable" upgraded to 2.19

       o   "Switch" upgraded to version 2.13

       o   "Sys::Syslog" upgraded to version 0.27

       o   "Term::ANSIColor" upgraded to version 1.12

       o   "Term::Cap" upgraded to version 1.12

       o   "Term::ReadLine" upgraded to version 1.03

       o   "Test::Builder" upgraded to version 0.80

       o   "Test::Harness" upgraded version to 2.64

           o   this makes it able to handle newlines.

       o   "Test::More" upgraded to version 0.80

       o   "Test::Simple" upgraded to version 0.80

       o   "Text::Balanced" upgraded to version 1.98

       o   "Text::ParseWords" upgraded to version 3.27

       o   "Text::Soundex" upgraded to version 3.03

       o   "Text::Tabs" upgraded to version 2007.1117

       o   "Text::Wrap" upgraded to version 2006.1117

       o   "Thread" upgraded to version 2.01

       o   "Thread::Semaphore" upgraded to version 2.09

       o   "Thread::Queue" upgraded to version 2.11

           o   added capability to add complex structures (e.g., hash of
               hashes) to queues.

           o   "Tie::Memoize::EXISTS" now correctly caches its results.

       o   "Tie::RefHash" upgraded to version 1.38

       o   "Tie::Scalar" upgraded to version 1.01

       o   "Tie::StdHandle" upgraded to version 4.2

       o   "Time::gmtime" upgraded to version 1.03

       o   "Time::Local" upgraded to version 1.1901

       o   "Time::HiRes" upgraded to version 1.9715 with various build
           improvements (including VMS) and minor platform-specific bug fixes
           (including for HP-UX 11 ia64).

       o   "threads" upgraded to 1.71

           o   new thread state information methods: "is_running",
               "is_detached" and "is_joinable".  "list" method enhanced to
               return running or joinable threads.

           o   new thread signal method: "kill"

           o   added capability to specify thread stack size.

           o   added capability to control thread exiting behavior.  Added a
               new "exit" method.

       o   "threads::shared" upgraded to version 1.27

           o   smaller and faster implementation that eliminates one internal
               structure and the consequent level of indirection.

           o   user locks are now stored in a safer manner.

           o   new function "shared_clone" creates a copy of an object leaving
               shared elements as-is and deep-cloning non-shared elements.

           o   added new "is_shared" method.

       o   "Unicode::Normalize" upgraded to version 1.02

       o   "Unicode::UCD" upgraded to version 0.25

       o   "warnings" upgraded to version 1.05_01

       o   "Win32" upgraded to version 0.38

           o   added new function "GetCurrentProcessId" which returns the
               regular Windows process identifier of the current process, even
               when called from within a fork.

       o   "XSLoader" upgraded to version 0.10
       o   The debugger should now correctly find tty the device on OS X 10.5
           and VMS when the program "fork"s.

       o   LVALUE subs now work inside the debugger.

   perlthanks
       Perl 5.8.9 adds a new utility perlthanks, which is a variant of
       perlbug, but for sending non-bug-reports to the authors and maintainers
       of Perl.  Getting nothing but bug reports can become a bit demoralising
       - we'll see if this changes things.

   perlbug
       perlbug now checks if you're reporting about a non-core module and
       suggests you report it to the CPAN author instead.

   h2xs
       o   won't define an empty string as a constant [RT #25366]

       o   has examples for "h2xs -X"

   h2ph
       o   now attempts to deal sensibly with the difference in path
           implications between "" and "<>" quoting in "#include" statements.

       o   now generates correct code for "#if defined A || defined B" [RT
           #39130]

New Documentation
       As usual, the documentation received its share of corrections,
       clarifications and other nitfixes. More "" tags were added for
       indexing.

       perlunitut is a tutorial written by Juerd Waalboer on Unicode-related
       terminology and how to correctly handle Unicode in Perl scripts.

       perlunicode is updated in section user defined properties.

       perluniintro has been updated in the example of detecting data that is
       not valid in particular encoding.

       perlcommunity provides an overview of the Perl Community along with
       further resources.

       CORE documents the pseudo-namespace for Perl's core routines.

Changes to Existing Documentation
       perlglossary adds deprecated modules and features and to be dropped
       modules.

       perlhack has been updated and added resources on smoke testing.

       The Perl FAQs (perlfaq1..perlfaq9) have been updated.

       perlcheat is updated with better details on "\w", "\d", and "\s".

       o   Function "alarm" now mentions "Time::HiRes::ualarm" in preference
           to "select".

       o   Regarding precedence in "-X", filetest operators are the same as
           unary operators, but not regarding parsing and parentheses (spotted
           by Eirik Berg Hanssen).

       o   reverse function documentation received scalar context examples.

       perllocale documentation is adjusted for number localization and
       "POSIX::setlocale" to fix Debian bug #379463.

       perlmodlib is updated with "CPAN::API::HOWTO" and
       "Sys::Syslog::win32::Win32"

       perlre documentation updated to reflect the differences between
       "[[:xxxxx:]]" and "\p{IsXxxxx}" matches. Also added section on "/g" and
       "/c" modifiers.

       perlreguts describe the internals of the regular expressions engine. It
       has been contributed by Yves Orton.

       perlrebackslash describes all perl regular expression backslash and
       escape sequences.

       perlrecharclass describes the syntax and use of character classes in
       Perl Regular Expressions.

       perlrun is updated to clarify on the hash seed PERL_HASH_SEED. Also
       more information in options "-x" and "-u".

       perlsub example is updated to use a lexical variable for "opendir"
       syntax.

       perlvar fixes confusion about real GID $( and effective GID $).

       Perl thread tutorial example is fixed in section "Queues: Passing Data
       Around" in perlthrtut and perlothrtut.

       perlhack documentation extensively improved by Jarkko Hietaniemi and
       others.

       perltoot provides information on modifying @UNIVERSAL::ISA.

       perlport documentation extended to include different "kill(-9, ...)"
       semantics on Windows. It also clearly states "dump" is not supported on
       Win32 and cygwin.

       INSTALL has been updated and modernised.

Performance Enhancements
       o   The default since perl 5.000 has been for perl to create an empty
           scalar with every new typeglob. The increased use of lexical
           see whether all third party code is compatible with it, as this
           configuration may give useful performance improvements. For
           existing installations we would not recommend changing to this
           configuration unless thorough testing is performed before
           deployment.

       o   "diagnostics" no longer uses $&, which results in large speedups
           for regexp matching in all code using it.

       o   Regular expressions classes of a single character are now treated
           the same as if the character had been used as a literal, meaning
           that code that uses char-classes as an escaping mechanism will see
           a speedup. (Yves Orton)

       o   Creating anonymous array and hash references (ie. "[]" and "{}")
           now incurs no more overhead than creating an anonymous list or
           hash. Nicholas Clark provided changes with a saving of two ops and
           one stack push, which was measured as a slightly better than 5%
           improvement for these operations.

       o   Many calls to "strlen()" have been eliminated, either because the
           length was already known, or by adopting or enhancing APIs that
           pass lengths. This has been aided by the adoption of a
           "my_sprintf()" wrapper, which returns the correct C89 value - the
           length of the formatted string. Previously we could not rely on the
           return value of "sprintf()", because on some ancient but extant
           platforms it still returns "char *".

       o   "index" is now faster if the search string is stored in UTF-8 but
           only contains characters in the Latin-1 range.

       o   The Unicode swatch cache inside the regexp engine is now used. (the
           lookup had a key mismatch, present since the initial
           implementation). [RT #42839]

Installation and Configuration Improvements
   Relocatable installations
       There is now Configure support for creating a relocatable perl tree. If
       you Configure with "-Duserelocatableinc", then the paths in @INC (and
       everything else in %Config) can be optionally located via the path of
       the perl executable.

       At start time, if any paths in @INC or "Config" that Configure marked
       as relocatable (by starting them with ".../"), then they are prefixed
       the directory of $^X. This allows the relocation can be configured on a
       per-directory basis, although the default with "-Duserelocatableinc" is
       that everything is relocated. The initial install is done to the
       original configured prefix.

   Configuration improvements
       Configure is now better at removing temporary files. Tom Callaway (from
       RedHat) also contributed patches that complete the set of flags passed
       to the compiler and the linker, in particular that "-fPIC" is now
       enabled on Linux. It will also croak when your /dev/null isn't a

   Compilation improvements
       Parallel makes should work properly now, although there may still be
       problems if "make test" is instructed to run in parallel.

       Many compilation warnings have been cleaned up. A very stubborn
       compiler warning in "S_emulate_eaccess()" was killed after six
       attempts.  g++ support has been tuned, especially for FreeBSD.

       mkppport has been integrated, and all ppport.h files in the core will
       now be autogenerated at build time (and removed during cleanup).

   Installation improvements.
       installman now works with "-Duserelocatableinc" and "DESTDIR".

       installperl no longer installs:

       o   static library files of statically linked extensions when a shared
           perl library is being used. (They are not needed. See "Windows"
           below).

       o   SIGNATURE and PAUSE*.pub (CPAN files)

       o   NOTES and PATCHING (ExtUtils files)

       o   perlld and ld2 (Cygwin files)

   Platform Specific Changes
       There are improved hints for AIX, Cygwin, DEC/OSF, FreeBSD, HP/UX, Irix
       6 Linux, MachTen, NetBSD, OS/390, QNX, SCO, Solaris, SunOS, System V
       Release 5.x (UnixWare 7, OpenUNIX 8), Ultrix, UMIPS, uts and VOS.

       FreeBSD

       o   Drop "-std=c89" and "-ansi" if using "long long" as the main
           integral type, else in FreeBSD 6.2 (and perhaps other releases),
           system headers do not declare some functions required by perl.

       Solaris

       o   Starting with Solaris 10, we do not want versioned shared
           libraries, because those often indicate a private use only library.
           These problems could often be triggered when SUNWbdb (Berkeley DB)
           was installed. Hence if Solaris 10 is detected set
           "ignore_versioned_solibs=y".

       VMS

       o   Allow IEEE math to be deselected on OpenVMS I64 (but it remains the
           default).

       o   Record IEEE usage in "config.h"

       o   Help older VMS compilers by using "ccflags" when building

       o   When using a shared perl library installperl no longer installs
           static library files, import library files and export library files
           (of statically linked extensions) and empty bootstrap files (of
           dynamically linked extensions). This fixes a problem building PAR-
           Packer on Win32 with a debug build of perl.

       o   Various improvements to the win32 build process, including support
           for Visual C++ 2005 Express Edition (aka Visual C++ 8.x).

       o   perl.exe will now have an icon if built with MinGW or Borland.

       o   Improvements to the perl-static.exe build process.

       o   Add Win32 makefile option to link all extensions statically.

       o   The WinCE directory has been merged into the Win32 directory.

       o   "setlocale" tests have been re-enabled for Windows XP onwards.

Selected Bug Fixes
   Unicode
       Many many bugs related to the internal Unicode implementation (UTF-8)
       have been fixed. In particular, long standing bugs related to returning
       Unicode via "tie", overloading or $@ are now gone, some of which were
       never reported.

       "unpack" will internally convert the string back from UTF-8 on numeric
       types.  This is a compromise between the full consistency now in 5.10,
       and the current behaviour, which is often used as a "feature" on string
       types.

       Using ":crlf" and "UTF-16" IO layers together will now work.

       Fixed problems with "split", Unicode "/\s+/" and "/ \0/".

       Fixed bug RT #40641 - encoding of Unicode characters in regular
       expressions.

       Fixed a bug where using certain patterns in a regexp led to a panic.
       [RT #45337]

       Perl no longer segfaults (due to infinite internal recursion) if the
       locale's character is not UTF-8 [RT #41442]:

           use open ':locale';
           print STDERR "\x{201e}"; # &bdquo;

   PerlIO
       Inconsistencies have been fixed in the reference counting PerlIO uses
       to keep track of Unix file descriptors, and the API used by XS code to
       manage getting and releasing "FILE *"s

   Magic

       A new entry has been added to the MAGIC vtable - "svt_local". This is
       used when copying magic to the new value during "local", allowing
       certain problems with localising shared variables to be resolved.

       For the implementation details, see "Magic Virtual Tables" in perlguts.

   Reblessing overloaded objects now works
       Internally, perl object-ness is on the referent, not the reference,
       even though methods can only be called via a reference. However, the
       original implementation of overloading stored flags related to
       overloading on the reference, relying on the flags being copied when
       the reference was copied, or set at the creation of a new reference.
       This manifests in a bug - if you rebless an object from a class that
       has overloading, into one that does not, then any other existing
       references think that they (still) point to an overloaded object,
       choose these C code paths, and then throw errors.  Analogously,
       blessing into an overloaded class when other references exist will
       result in them not using overloading.

       The implementation has been fixed for 5.10, but this fix changes the
       semantics of flag bits, so is not binary compatible, so can't be
       applied to 5.8.9.  However, 5.8.9 has a work-around that implements the
       same bug fix. If the referent has multiple references, then all the
       other references are located and corrected. A full search is avoided
       whenever possible by scanning lexicals outwards from the current
       subroutine, and the argument stack.

       A certain well known Linux vendor applied incomplete versions of this
       bug fix to their /usr/bin/perl and then prematurely closed bug reports
       about performance issues without consulting back upstream. This not
       being enough, they then proceeded to ignore the necessary fixes to
       these unreleased changes for 11 months, until massive pressure was
       applied by their long-suffering paying customers, catalysed by the
       failings being featured on a prominent blog and Slashdot.

   "strict" now propagates correctly into string evals
       Under 5.8.8 and earlier:

           $ perl5.8.8 -e 'use strict; eval "use foo bar" or die $@'
           Can't locate foo.pm in @INC (@INC contains: ... .) at (eval 1) line 2.
           BEGIN failed--compilation aborted at (eval 1) line 2.

       Under 5.8.9 and later:

           $ perl5.8.9 -e 'use strict; eval "use foo bar" or die $@'
           Bareword "bar" not allowed while "strict subs" in use at (eval 1) line 1.

       This may cause problems with programs that parse the error message and
       rely on the buggy behaviour.

   Other fixes
       o   The tokenizer no longer treats "=cute" (and other words beginning
           with "=cut") as a synonym for "=cut".
           so that "redo" doesn't "undef" the lexical.

       o   The "encoding" pragma now correctly ignores anything following an
           "@" character in the "LC_ALL" and "LANG" environment variables. [RT
           # 49646]

       o   A segfault observed with some gcc 3.3 optimisations is resolved.

       o   A possible segfault when "unpack" used in scalar context with "()"
           groups is resolved. [RT #50256]

       o   Resolved issue where $! could be changed by a signal handler
           interrupting a "system" call.

       o   Fixed bug RT #37886, symbolic dereferencing was allowed in the
           argument of "defined" even under the influence of "use strict
           'refs'".

       o   Fixed bug RT #43207, where "lc"/"uc" inside "sort" affected the
           return value.

       o   Fixed bug RT #45607, where "*{"BONK"} = \&{"BONK"}" didn't work
           correctly.

       o   Fixed bug RT #35878, croaking from a XSUB called via "goto &xsub"
           corrupts perl internals.

       o   Fixed bug RT #32539, DynaLoader.o is moved into libperl.so to avoid
           the need to statically link DynaLoader into the stub perl
           executable. With this libperl.so provides everything needed to get
           a functional embedded perl interpreter to run.

       o   Fix bug RT #36267 so that assigning to a tied hash doesn't change
           the underlying hash.

       o   Fix bug RT #6006, regexp replaces using large replacement variables
           fail some of the time, i.e. when substitution contains something
           like "${10}" (note the bracket) instead of just $10.

       o   Fix bug RT #45053, "Perl_newCONSTSUB()" is now thread safe.

   Platform Specific Fixes
       Darwin / MacOS X

       o   Various improvements to 64 bit builds.

       o   Mutex protection added in "PerlIOStdio_close()" to avoid race
           conditions.  Hopefully this fixes failures in the threads tests
           free.t and blocks.t.

       o   Added forked terminal support to the debugger, with the ability to
           update the window title.

       OS/2
       o   Revisited a patch from 5.6.1 for RH7.2 for Intel's icc [RT #7916],
           added an additional check for $Config{gccversion}.

       Solaris/i386

       o   Use "-DPTR_IS_LONG" when using 64 bit integers

       VMS

       o   Fixed "PerlIO::Scalar" in-memory file record-style reads.

       o   pipe shutdown at process exit should now be more robust.

       o   Bugs in VMS exit handling tickled by "Test::Harness" 2.64 have been
           fixed.

       o   Fix "fcntl()" locking capability test in configure.com.

       o   Replaced "shrplib='define'" with "useshrplib='true'" on VMS.

       Windows

       o   "File::Find" used to fail when the target directory is a bare drive
           letter and "no_chdir" is 1 (the default is 0). [RT #41555]

       o   A build problem with specifying "USE_MULTI" and "USE_ITHREADS" but
           without "USE_IMP_SYS" has been fixed.

       o   The process id is no longer truncated to 16 bits on some Windows
           platforms ( http://bugs.activestate.com/show_bug.cgi?id=72443 )

       o   Fixed bug RT #54828 in perlio.c where calling "binmode" on Win32
           and Cygwin may cause a segmentation fault.

   Smaller fixes
       o   It is now possible to overload "eq" when using "nomethod".

       o   Various problems using "overload" with 64 bit integers corrected.

       o   The reference count of "PerlIO" file descriptors is now correctly
           handled.

       o   On VMS, escaped dots will be preserved when converted to Unix
           syntax.

       o   "keys %+" no longer throws an 'ambiguous' warning.

       o   Using "#!perl -d" could trigger an assertion, which has been fixed.

       o   Don't stringify tied code references in @INC when calling
           "require".

       o   Code references in @INC report the correct file name when
           "__FILE__" is used.
           its OP, rather than in a pad.

       o   pod2html labels anchors more consistently and handles nested
           definition lists better.

       o   "threads" cleanup veto has been extended to include "perl_free()"
           and "perl_destruct()"

       o   On some systems, changes to $ENV{TZ} would not always be respected
           by the underlying calls to "localtime_r()".  Perl now forces the
           inspection of the environment on these systems.

       o   The special variable $^R is now more consistently set when
           executing regexps using the "(?{...})" construct.  In particular,
           it will still be set even if backreferences or optional sub-
           patterns "(?:...)?" are used.

New or Changed Diagnostics
   panic: sv_chop %s
       This new fatal error occurs when the C routine "Perl_sv_chop()" was
       passed a position that is not within the scalar's string buffer. This
       is caused by buggy XS code, and at this point recovery is not possible.

   Maximal count of pending signals (%s) exceeded
       This new fatal error occurs when the perl process has to abort due to
       too many pending signals, which is bound to prevent perl from being
       able to handle further incoming signals safely.

   panic: attempt to call %s in %s
       This new fatal error occurs when the ACL version file test operator is
       used where it is not available on the current platform. Earlier checks
       mean that it should never be possible to get this.

   FETCHSIZE returned a negative value
       New error indicating that a tied array has claimed to have a negative
       number of elements.

   Can't upgrade %s (%d) to %d
       Previously the internal error from the SV upgrade code was the less
       informative Can't upgrade that kind of scalar. It now reports the
       current internal type, and the new type requested.

   %s argument is not a HASH or ARRAY element or a subroutine
       This error, thrown if an invalid argument is provided to "exists" now
       correctly includes "or a subroutine". [RT #38955]

   Cannot make the non-overridable builtin %s fatal
       This error in "Fatal" previously did not show the name of the builtin
       in question (now represented by %s above).

   Unrecognized character '%s' in column %d
       This error previously did not state the column.

   Offset outside string
       useful than silently exiting.)

Changed Internals
       The perl sources can now be compiled with a C++ compiler instead of a C
       compiler. A necessary implementation details is that under C++, the
       macro "XS" used to define XSUBs now includes an "extern "C""
       definition. A side effect of this is that C++ code that used the
       construction

           typedef XS(SwigPerlWrapper);

       now needs to be written

           typedef XSPROTO(SwigPerlWrapper);

       using the new "XSPROTO" macro, in order to compile. C extensions are
       unaffected, although C extensions are encouraged to use "XSPROTO" too.
       This change was present in the 5.10.0 release of perl, so any actively
       maintained code that happened to use this construction should already
       have been adapted. Code that needs changing will fail with a
       compilation error.

       "set" magic on localizing/assigning to a magic variable will now only
       trigger for container magics, i.e. it will for %ENV or %SIG but not for
       $#array.

       The new API macro "newSVpvs()" can be used in place of constructions
       such as "newSVpvn("ISA", 3)". It takes a single string constant, and at
       C compile time determines its length.

       The new API function "Perl_newSV_type()" can be used as a more
       efficient replacement of the common idiom

           sv = newSV(0);
           sv_upgrade(sv, type);

       Similarly "Perl_newSVpvn_flags()" can be used to combine
       "Perl_newSVpv()" with "Perl_sv_2mortal()" or the equivalent
       "Perl_sv_newmortal()" with "Perl_sv_setpvn()"

       Two new macros "mPUSHs()" and "mXPUSHs()" are added, to make it easier
       to push mortal SVs onto the stack. They were then used to fix several
       bugs where values on the stack had not been mortalised.

       A "Perl_signbit()" function was added to test the sign of an "NV". It
       maps to the system one when available.

       "Perl_av_reify()", "Perl_lex_end()", "Perl_mod()", "Perl_op_clear()",
       "Perl_pop_return()", "Perl_qerror()", "Perl_setdefout()",
       "Perl_vivify_defelem()" and "Perl_yylex()" are now visible to
       extensions.  This was required to allow "Data::Alias" to work on
       Windows.

       "Perl_find_runcv()" is now visible to perl core extensions. This was
       A lot of small improvements in the code base were made due to reports
       from the Coverity static code analyzer.

       Corrected use and documentation of "Perl_gv_stashpv()",
       "Perl_gv_stashpvn()", "Perl_gv_stashsv()" functions (last parameter is
       a bitmask, not boolean).

       "PERL_SYS_INIT", "PERL_SYS_INIT3" and "PERL_SYS_TERM" macros have been
       changed into functions.

       "PERLSYS_TERM" no longer requires a context. "PerlIO_teardown()" is now
       called without a context, and debugging output in this function has
       been disabled because that required that an interpreter was present, an
       invalid assumption at termination time.

       All compile time options which affect binary compatibility have been
       grouped together into a global variable ("PL_bincompat_options").

       The values of "PERL_REVISION", "PERL_VERSION" and "PERL_SUBVERSION" are
       now baked into global variables (and hence into any shared perl
       library).  Additionally under "MULTIPLICITY", the perl executable now
       records the size of the interpreter structure (total, and for this
       version). Coupled with "PL_bincompat_options" this will allow 5.8.10
       (and later), when compiled with a shared perl library, to perform
       sanity checks in "main()" to verify that the shared library is indeed
       binary compatible.

       Symbolic references can now have embedded NULs. The new public function
       "Perl_get_cvn_flags()" can be used in extensions if you have to handle
       them.

   Macro cleanups
       The core code, and XS code in ext that is not dual-lived on CPAN, no
       longer uses the macros "PL_na", "NEWSV()", "Null()", "Nullav",
       "Nullcv", "Nullhv", "Nullhv" etc. Their use is discouraged in new code,
       particularly "PL_na", which is a small performance hit.

New Tests
       Many modules updated from CPAN incorporate new tests. Some core
       specific tests have been added:

       ext/DynaLoader/t/DynaLoader.t
           Tests for the "DynaLoader" module.

       t/comp/fold.t
           Tests for compile-time constant folding.

       t/io/pvbm.t
           Tests incorporated from 5.10.0 which check that there is no
           unexpected interaction between the internal types "PVBM" and
           "PVGV".

       t/lib/proxy_constant_subs.t
           Tests for the new form of constant subroutines.

       t/op/kill0.t
           Tests for RT #30970.

       t/op/qrstack.t
           Tests for RT #41484.

       t/op/qr.t
           Tests for the "qr//" construct.

       t/op/regexp_qr_embed.t
           Tests for the "qr//" construct within another regexp.

       t/op/regexp_qr.t
           Tests for the "qr//" construct.

       t/op/rxcode.t
           Tests for RT #32840.

       t/op/studytied.t
           Tests for "study" on tied scalars.

       t/op/substT.t
           Tests for "subst" run under "-T" mode.

       t/op/symbolcache.t
           Tests for "undef" and "delete" on stash entries that are bound to
           subroutines or methods.

       t/op/upgrade.t
           Tests for "Perl_sv_upgrade()".

       t/mro/package_aliases.t
           MRO tests for "isa" and package aliases.

       t/pod/twice.t
           Tests for calling "Pod::Parser" twice.

       t/run/cloexec.t
           Tests for inheriting file descriptors across "exec" (close-on-
           exec).

       t/uni/cache.t
           Tests for the UTF-8 caching code.

       t/uni/chr.t
           Test that strange encodings do not upset "Perl_pp_chr()".

       t/uni/greek.t
           Tests for RT #40641.

       t/uni/latin2.t
           Tests for RT #40641.

       incompatible, or because the code changes are too large and hence too
       risky to incorporate.

       We have only limited volunteer labour, and the maintenance burden is
       getting increasingly complex. Hence this will be the last significant
       release of the 5.8.x series. Any future releases of 5.8.x will likely
       only be to deal with security issues, and platform build failures.
       Hence you should look to migrating to 5.10.x, if you have not started
       already. Alternatively, if business requirements constrain you to
       continue to use 5.8.x, you may wish to consider commercial support from
       firms such as ActiveState.

Platform Specific Notes
   Win32
       "readdir()", "cwd()", $^X and @INC now use the alternate (short)
       filename if the long name is outside the current codepage (Jan Dubois).

       Updated Modules

       o   "Win32" upgraded to version 0.38. Now has a documented 'WinVista'
           response from "GetOSName" and support for Vista's privilege
           elevation in "IsAdminUser".  Support for Unicode characters in path
           names. Improved cygwin and Win64 compatibility.

       o   "Win32API" updated to 0.1001_01

       o   "killpg()" support added to "MSWin32" (Jan Dubois).

       o   "File::Spec::Win32" upgraded to version 3.2701

   OS/2
       Updated Modules

       o   "OS2::Process" upgraded to 1.03

           Ilya Zakharevich has added and documented several "Window*" and
           "Clipbrd*" functions.

       o   "OS2::REXX::DLL", "OS2::REXX" updated to version 1.03

   VMS
       Updated Modules

       o   "DCLsym" upgraded to version 1.03

       o   "Stdio" upgraded to version 2.4

       o   "VMS::XSSymSet" upgraded to 1.1.

Obituary
       Nick Ing-Simmons, long time Perl hacker, author of the "Tk" and
       "Encode" modules, perlio.c in the core, and 5.003_02 pumpking, died of
       a heart attack on 25th September 2006. He will be missed.


       Schwern verified the list of updated module versions, correcting quite
       a few errors that I (and everyone else) had missed, both wrongly stated
       module versions, and changed modules that had not been listed.

       The crack Berlin-based QA team of Andreas Koenig and Slaven Rezic
       tirelessly re-built snapshots, tested most everything CPAN against
       them, and then identified the changes responsible for any module
       regressions, ensuring that several show-stopper bugs were stomped
       before the first release candidate was cut.

       The other core committers contributed most of the changes, and applied
       most of the patches sent in by the hundreds of contributors listed in
       AUTHORS.

       And obviously, Larry Wall, without whom we wouldn't have Perl.

Reporting Bugs
       If you find what you think is a bug, you might check the articles
       recently posted to the comp.lang.perl.misc newsgroup and the perl bug
       database at http://bugs.perl.org.  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.  You can browse and search the Perl 5 bugs at
       http://bugs.perl.org/

       If the bug you are reporting has security implications, which make it
       inappropriate to send to a publicly archived mailing list, then please
       send it to perl5-security-report@perl.org. This points to a closed
       subscription unarchived mailing list, which includes all the core
       committers, who be able to help assess the impact of issues, figure out
       a resolution, and help co-ordinate the release of patches to mitigate
       or fix the problem across all platforms on which Perl is supported.
       Please only use this address for security issues in the Perl core, not
       for modules independently distributed on CPAN.

SEE ALSO
       The Changes file for exhaustive details on what changed.

       The INSTALL file for how to build Perl.

       The README file for general stuff.

       The Artistic and Copying files for copyright information.



perl v5.14.2                      2011-09-26                   PERL589DELTA(1)
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