PERL5139DELTA(1) Perl Programmers Reference Guide PERL5139DELTA(1)NAME
perl5139delta - what is new for perl v5.13.9
DESCRIPTION
This document describes differences between the 5.13.8 release and the
5.13.9 release.
If you are upgrading from an earlier release such as 5.13.7, first read
perl5138delta, which describes differences between 5.13.7 and 5.13.8.
Core Enhancements
New regular expression modifier "/a"
The "/a" regular expression modifier restricts "\s" to match precisely
the five characters "[ \f\n\r\t]", "\d" to match precisely the 10
characters "[0-9]", "\w" to match precisely the 63 characters
"[A-Za-z0-9_]", and the Posix ("[[:posix:]]") character classes to
match only the appropriate ASCII characters. The complements, of
course, match everything but; and "\b" and "\B" are correspondingly
affected. Otherwise, "/a" behaves like the "/u" modifier, in that
case-insensitive matching uses Unicode semantics; for example, "k" will
match the Unicode "\N{KELVIN SIGN}" under "/i" matching, and code
points in the Latin1 range, above ASCII will have Unicode semantics
when it comes to case-insensitive matching. Like its cousins ("/u",
"/l", and "/d"), and in spite of the terminology, "/a" in 5.14 will not
actually be able to be used as a suffix at the end of a regular
expression (this restriction is planned to be lifted in 5.16). It must
occur either as an infix modifier, such as "(?a:...)" or ("(?a)...", or
it can be turned on within the lexical scope of "use re '/a'". Turning
on "/a" turns off the other "character set" modifiers.
Any unsigned value can be encoded as a character
With this release, Perl is adopting a model that any unsigned value can
be treated as a code point and encoded internally (as utf8) without
warnings -- not just the code points that are legal in Unicode.
However, unless utf8 warnings have been explicitly lexically turned
off, outputting or performing a Unicode-defined operation (such as
upper-casing) on such a code point will generate a warning. Attempting
to input these using strict rules (such as with the
":encoding('UTF-8')" layer) will continue to fail. Prior to this
release the handling was very inconsistent, and incorrect in places.
Also, the Unicode non-characters, some of which previously were
erroneously considered illegal in places by Perl, contrary to the
Unicode standard, are now always legal internally. But inputting or
outputting them will work the same as for the non-legal Unicode code
points, as the Unicode standard says they are illegal for "open
interchange".
Regular expression debugging output improvement
Regular expression debugging output (turned on by "use re 'debug';")
now uses hexadecimal when escaping non-ASCII characters, instead of
octal.
Security
Restrict \p{IsUserDefined} to In\w+ and Is\w+
In "User-Defined Character Properties" in perlunicode, it says you can
create custom properties by defining subroutines whose names begin with
"In" or "Is". However, perl doesn't actually enforce that naming
restriction, so \p{foo::bar} will call foo::Bar() if it exists.
This commit finally enforces this convention. Note that this broke a
number of existing tests for properties, since they didn't always use
an Is/In prefix.
Incompatible Changes
All objects are destroyed
It used to be possible to prevent a destructor from being called during
global destruction by artificially increasing the reference count of an
object.
Now such objects will will be destroyed, as a result of a bug fix [perl
#81230] <http://rt.perl.org/rt3/Public/Bug/Display.html?id=81230>.
This has the potential to break some XS modules. (In fact, it break
some. See "Known Problems", below.)
Modules and Pragmata
New Modules and Pragmata
· "CPAN::Meta::YAML" 0.003 has been added as a dual-life module. It
supports a subset of YAML sufficient for reading and writing
META.yml and MYMETA.yml files included with CPAN distributions or
generated by the module installation toolchain. It should not be
used for any other general YAML parsing or generation task.
· "HTTP::Tiny" 0.009 has been added as a dual-life module. It is a
very small, simple HTTP/1.1 client designed for simple GET requests
and file mirroring. It has has been added to enable CPAN.pm and
CPANPLUS to "bootstrap" HTTP access to CPAN using pure Perl without
relying on external binaries like curl or wget.
· "JSON::PP" 2.27103 has been added as a dual-life module, for the
sake of reading META.json files in CPAN distributions.
· "Module::Metadata" 1.000003 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 (e.g. 'dragonfly' or 'MSWin32') to more
generic types with standardized names (e.g. "Unix" or "Windows").
It has been refactored out of Module::Build and ExtUtils::CBuilder
and consolidates such mappings into a single location for easier
maintenance.
Updated Modules and Pragmata
· "Archive::Extract" has been upgraded from version 0.46 to 0.48
· "Archive::Tar" has been upgraded from version 1.74 to 1.76
· "CGI" has been upgraded from version 3.50 to 3.51
Further improvements have been made to guard against newline
injections in headers.
· "Compress::Raw::Bzip2" has been upgraded from version 2.031 to
2.033
· "Compress::Raw::Zlib" has been upgraded from version 2.030 to 2.033
· "CPAN" has been upgraded from version 1.94_62 to 1.94_63
· "CPANPLUS" has been upgraded from version 0.9010 to 0.9011
· "CPANPLUS::Dist::Build" has been upgraded from version 0.50 to 0.52
· "DB_File" has been upgraded from version 1.820 to 1.821
· "Encode" has been upgraded from version 2.40 to 2.42. Now, all 66
Unicode non-characters are treated the same way U+FFFF has always
been treated; if it was disallowed, all 66 are disallowed; if it
warned, all 66 warn.
· "File::Fetch" has been upgraded from version 0.28 to 0.32
· "IO::Compress" has been upgraded from version 2.030 to 2.033
· "IPC::Cmd" has been upgraded from version 0.66 to 0.68
· "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
· "Module::Load::Conditional" has been upgraded from version 0.38 to
0.40
· "Object::Accessor" has been upgraded from version 0.36 to 0.38
· "Params::Check" has been upgraded from version 0.26 to 0.28
· "Pod::LaTeX" has been upgraded from version 0.58 to 0.59
· "Socket" has been updated with new affordances for IPv6, including
implementations of the "Socket::getaddrinfo()" and
"Socket::getnameinfo()" functions, along with related constants.
· "Term::UI" has been upgraded from version 0.20 to 0.24
· "Thread::Queue" has been upgraded from version 2.11 to 2.12.
· "Thread::Semaphore" has been upgraded from version 2.11 to 2.12.
· "threads" has been upgraded from version 1.81_03 to 1.82
· "threads::shared" has been upgraded from version 1.35 to 1.36
· "Time::Local" has been upgraded from version 1.1901_01 to 1.2000.
· "Unicode::Normalize" has been upgraded from version 1.07 to 1.10
· "version" has been upgraded from 0.86 to 0.88.
· "Win32" has been upgraded from version 0.41 to 0.44.
Documentation
Changes to Existing Documentation
All documentation
· Numerous POD warnings were fixed.
· Many, many spelling errors and typographical mistakes were
corrected throughout Perl's core.
"perlhack"
· "perlhack" was extensively reorganized.
"perlfunc"
· It has now been documented that "ord" returns 0 for an empty
string.
Diagnostics
The following additions or changes have been made to diagnostic output,
including warnings and fatal error messages. For the complete list of
diagnostic messages, see perldiag.
New Diagnostics
· Performing an operation requiring Unicode semantics (such as case-
folding) on a Unicode surrogate or a non-Unicode character now
triggers a warning: 'Operation "%s" returns its argument for ...'.
Changes to Existing Diagnostics
· Previously, if none of the "gethostbyaddr", "gethostbyname" and
"gethostent" functions were implemented on a given platform, they
would all die with the message 'Unsupported socket function
"gethostent" called', with analogous messages for "getnet*" and
"getserv*". This has been corrected.
Utility Changes
"perlbug"
· "perlbug" did not previously generate a From: header, potentially
resulting in dropped mail. Now it does include that header.
"buildtoc"
· pod/buildtoc has been modernized and can now be used to test the
well-formedness of pod/perltoc.pod automatically.
Testing
· "lib/File/DosGlob.t" has been modernized and now uses "Test::More".
· A new test script, "t/porting/filenames.t", makes sure that
filenames and paths are reasonably portable.
· "t/porting/diag.t" is now several orders of magnitude faster.
· "t/porting/buildtoc.t" now tests that the documentation TOC file is
current and well-formed.
· "t/base/while.t" now tests the basics of a while loop with minimal
dependencies.
· "t/cmd/while.t" now uses test.pl for better maintainability.
· "t/op/split.t" now tests calls to "split" without any pattern
specified.
Platform Support
Discontinued Platforms
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.
Platform-Specific Notes
Cygwin
· Updated MakeMaker to build man pages on cygwin.
· Improved rebase behaviour
If a dll is updated on cygwin reuse the old imagebase address.
This solves most rebase errors, esp when updating on core
dll's. See
http://www.tishler.net/jason/software/rebase/rebase-2.4.2.README
<http://www.tishler.net/jason/software/rebase/rebase-2.4.2.README>
for more information.
· Support the standard cyg dll prefix, which is e.g. needed for
FFI's.
· Updated build hints file
Solaris
DTrace is now supported on Solaris. There used to be build
failures, but these have been fixed [perl #73630]
<http://rt.perl.org/rt3/Public/Bug/Display.html?id=73630>.
Internal Changes
· The opcode bodies for "chop" and "chomp" and for "schop" and
"schomp" have been merged. The implementation functions
"Perl_do_chop()" and "Perl_do_chomp()", never part of the public
API, have been merged and moved to a static function in pp.c. This
shrinks the perl binary slightly, and should not affect any code
outside the core (unless it is relying on the order of side effects
when "chomp" is passed a list of values).
· Some of the flags parameters to the uvuni_to_utf8_flags() and
utf8n_to_uvuni() have changed. This is a result of Perl 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 these
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 "Selected Bug
Fixes".
· Certain shared flags in the "pmop.op_pmflags" and "regexp.extflags"
structures have been removed. These are: "Rxf_Pmf_LOCALE",
"Rxf_Pmf_UNICODE", and "PMf_LOCALE". Instead there are encodes and
three static in-line functions for accessing the information:
"get_regex_charset()", "set_regex_charset()", and
"get_regex_charset_name()", which are defined in the places where
the original flags were.
· A new option 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
· Generate pp_* prototypes in pp_proto.h, and remove pp.sym
Eliminate the #define pp_foo Perl_pp_foo(pTHX) macros, and update
the 13 locations that relied on them.
regen/opcode.pl now generates prototypes for the PP functions
directly, into pp_proto.h. It no longer writes pp.sym, and
regen/embed.pl no longer reads this, removing the only ordering
dependency in the regen scripts. opcode.pl is now responsible for
prototypes for pp_* functions. (embed.pl remains responsible for
ck_* functions, reading from regen/opcodes)
Selected Bug Fixes
· The handling of Unicode non-characters has changed. Previously
they were mostly considered illegal, except that only one of the 66
of them was known about in places. The Unicode standard considers
them legal, but forbids the "open interchange" of them. This is
part of the change to allow the internal use of any code point (see
"Core Enhancements"). Together, these changes resolve # 38722
<https://rt.perl.org/rt3/Ticket/Display.html?id=38722>, # 51918
<http://rt.perl.org/rt3/Ticket/Display.html?id=51918>, # 51936
<http://rt.perl.org/rt3/Ticket/Display.html?id=51936>, # 63446
<http://rt.perl.org/rt3/Ticket/Display.html?id=63446>
· Sometimes magic (ties, tainted, 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]
<http://rt.perl.org/rt3/Public/Bug/Display.html?id=81230>.
· 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 was always meant to be the case.
· "<expr>" always respects overloading now if the expression is
overloaded.
Due to the way that '<> 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.
· Destructors on objects were not called during global destruction on
objects that were not referenced by any scalars. This could happen
if an array element were blessed (e.g., "bless \$a[0]") or if a
closure referenced a blessed variable ("bless \my @a; sub foo { @a
}").
Now there is an extra pass during global destruction to fire
destructors on any objects that might be left after the usual
passes that check for objects referenced by scalars [perl #36347]
<http://rt.perl.org/rt3/Public/Bug/Display.html?id=36347>.
· A long standing bug has now been fully fixed (partial fixes came in
earlier releases), in which some Latin-1 non-ASCII characters on
ASCII-platforms would match both a character class and its
complement, such as U+00E2 being both in "\w" and "\W", depending
on the UTF-8-ness of the regular expression pattern and target
string. Fixing this did expose some bugs in various modules and
tests that relied on the previous behavior of "[[:alpha:]]" not
ever matching U+00FF, "LATIN SMALL LETTER Y WITH DIAERESIS", even
when it should, in Unicode mode; now it does match when
appropriate. [perl #60156]
<http://rt.perl.org/rt3/Ticket/Display.html?id=60156>.
Known Problems
· The fix for [perl #81230] causes test failures for "Tk" version
804.029. This is still being investigated.
Acknowledgements
Perl 5.13.9 represents approximately one month of development since
Perl 5.13.8 and contains approximately 48000 lines of changes across
809 files from 35 authors and committers:
Abigail, var Arnfjoer` Bjarmason, brian d foy, Chris 'BinGOs' Williams,
Craig A. Berry, David Golden, David Leadbeater, David Mitchell, Father
Chrysostomos, Florian Ragwitz, Gerard Goossen, H.Merijn Brand, Jan
Dubois, Jerry D. Hedden, Jesse Vincent, John Peacock, Karl Williamson,
Leon Timmermans, Michael Parker, Michael Stevens, Nicholas Clark, Nuno
Carvalho, Paul "LeoNerd" Evans, Peter J. Acklam, Peter Martini, Rainer
Tammer, Reini Urban, Renee Baecker, Ricardo Signes, Robin Barker, Tony
Cook, Vadim Konovalov, Vincent Pit, Zefram, and Zsban Ambrus.
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.
Reporting Bugs
If you find what you think is a bug, you might check the articles
recently posted to the comp.lang.perl.misc newsgroup and the perl bug
database at http://rt.perl.org/perlbug/ . There may also be
information at http://www.perl.org/ , the Perl Home Page.
If you believe you have an unreported bug, please run the 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 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 an explanation of how to view 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 PERL5139DELTA(1)