[ this is a template for a new perldelta file. Any text flagged as XXX needs
to be processed before release. ]
-perldelta - what is new for perl v5.19.1
+perldelta - what is new for perl v5.19.3
=head1 DESCRIPTION
-This document describes differences between the 5.19.0 release and the 5.19.1
+This document describes differences between the 5.19.2 release and the 5.19.3
release.
+If you are upgrading from an earlier release such as 5.19.1, first read
+L<perl5192delta>, which describes differences between 5.19.1 and 5.19.2.
+
=head1 Notice
XXX Any important notices here
[ List each enhancement as a =head2 entry ]
+=head2 B<-F> now implies B<-a> and B<-a> implies B<-n>
+
+Previously B<-F> without B<-a> was a no-op, and B<-a> without B<-n> or
+B<-p> was a no-op, with this change, if you supply B<-F> then both
+B<-a> and B<-n> are implied and if you supply B<-a> then B<-n> is implied.
+
+You can still use B<-p> for its extra behaviour. [perl #116190]
+
=head1 Security
XXX Any security-related notices go here. In particular, any security
[ List each incompatible change as a =head2 entry ]
-=head2 Most regex engine global state eliminated
-
-As part of this series of fixes it was necessary to change the API of
-Perl_re_intuit_start(). See L</Internal Changes> for more.
-
-=head2 Locale decimal point character no longer leaks outside of S<C<use locale>> scope
-
-This is actually a bug fix, but some code has come to rely on the bug
-being present, so this change is listed here. The current locale that
-the program is running under is not supposed to be visible to Perl code
-except within the scope of a S<C<use locale>>. However, until now under
-certain circumstances, the character used for a decimal point (often a
-comma) leaked outside the scope. If your code is affected by this
-change, simply add a S<C<use locale>>.
-
=head1 Deprecations
XXX Any deprecated features, syntax, modules etc. should be listed here.
XXX Remove this section if inapplicable.
-The following modules will be removed from the core distribution in a future
-release, and will at that time need to be installed from CPAN. Distributions
-on CPAN which require these modules will need to list them as prerequisites.
+The following modules will be removed from the core distribution in a
+future release, and will at that time need to be installed from CPAN.
+Distributions on CPAN which require these modules will need to list them as
+prerequisites.
The core versions of these modules will now issue C<"deprecated">-category
-warnings to alert you to this fact. To silence these deprecation warnings,
+warnings to alert you to this fact. To silence these deprecation warnings,
install the modules in question from CPAN.
Note that these are (with rare exceptions) fine modules that you are encouraged
-to continue to use. Their disinclusion from core primarily hinges on their
+to continue to use. Their disinclusion from core primarily hinges on their
necessity to bootstrapping a fully functional, CPAN-capable Perl installation,
not usually on concerns over their design.
-XXX Note that deprecated modules should be listed here even if they are listed
-as an updated module in the L</Modules and Pragmata> section.
-
=over
-=item *
-
-XXXX
+XXX Note that deprecated modules should be listed here even if they are listed
+as an updated module in the L</Modules and Pragmata> section.
=back
=item *
-Perl has a new copy-on-write mechanism that avoids the need to copy the
-internal string buffer when assigning from one scalar to another. This
-makes copying large strings appear much faster. Modifying one of the two
-(or more) strings after an assignment will force a copy internally. This
-makes it unnecessary to pass strings by reference for efficiency.
-
-This feature was already available in 5.18.0, but wasn't enabled by
-default. It is the default now, and so you no longer need build perl with
-the F<Configure> argument:
-
- -Accflags=PERL_NEW_COPY_ON_WRITE
-
-It can be disabled (for now) in a perl build with:
-
- -Accflags=PERL_NO_COW
+XXX
=back
=item *
-L<Module::CoreList::Utils> which provides information on which core and
-dual-life utilities shipped with each version of L<perl>.
+XXX
=back
=item *
-L<B::Deparse> has been upgraded from version 1.20 to 1.21.
+L<B> has been upgraded from version 1.44 to 1.45.
-C<foreach my $lexical> is now deparsed correctly with the B<-p> option.
-[RT #117081]
+Calling the C<GV> method on C<B::CV> objects created from a lexical
+sub would return nonsense, possibly crashing perl. C<GV> now returns
+C<undef> for lexical subs. [perl #118525]
-The B<-l> option no longer puts form feeds in the middle of a line when
-outputting C<map> and C<grep> blocks. [RT #117311]
+Added the C<NAME_HEK> method to return the name of a lexical sub.
-Elements of C<%#>, such as C<$# {foo}> and C<${#}{foo}> are now deparsed
-correctly. [RT #117531]
+=item *
+
+L<bignum> has been upgraded from version 0.35 to 0.36.
+
+L<bigrat> wasn't correctly updating an internal variable when C<use>d
+with a C<lib> option.
+
+L<Carp> has been upgraded from 1.30 to 1.31
+
+L<Carp> now handles objects with string overloads. It also allows objects
+to specify how they appear in the stack dump with a C<CARP_TRACE> method,
+and also allows the user to specify their own formatter for objects without
+C<CARP_TRACE> as well as other references. [perl #92446]
=item *
-L<DB> has been updated from 1.05 to 1.06 and L<perl5db.pl> from 1.39_10
-to 1.40. The call depth allowed by default in the debugger is now 1000
-rather than 100.
+L<Compress::Raw::Bzip2> has been upgraded from 2.061 to 2.062.
=item *
-L<File::Spec> has been upgraded from version 3.40 to 3.41.
+L<Compress::Raw::Zlib> has been upgraded from 2.061 to 2.062.
+
+=item *
-C<tmpdir> now respects changes to environment variables from which the
-temporary directory is derived. [RT #88940]
+L<Config::Perl::V> has been upgraded from version 0.18 to 0.19.
=item *
-L<Test::Harness> has been upgraded from version 3.26 to 3.28
+L<Data::Dumper> has been upgraded from version 2.147 to 2.148.
-Memory usage is dramatically reduced. t/harness now uses about 10% of the
-memory used by 3.26 and earlier.
+The compatbility of the XS implementation with the pure perl version
+under C<Useqq> has been improved. [perl #118933]
-C<PERL5LIB> is always propagated to a test's C<@INC>, even under C<-T>.
+=item *
+
+L<Devel::Peek> has been upgraded from version 1.12 to 1.13.
+
+The C<SvREFCNT_inc()> and C<SvREFCNT_dec()> functions have been
+removed and C<SvREFCNT()> will now work on non-scalars. [perl #117793]
=item *
-L<Unicode::UCD> has been upgraded from version 0.51 to 0.52.
+L<Exporter> has been upgraded from version 5.68 to 5.69.
-A function, L<Unicode::UCD/search_invlist()> is now available to do
-search an inversion list or map for a code point.
+L<Exporter> would ignore custom C<$SIG{__WARN__}> handlers in
+C<Exporter::Heavy>. [perl #39739]
+
+=item *
+
+The IO-Compress module collection has been upgraded from 2.061 to 2.062.
+
+=item *
+
+L<IPC::Cmd> has been upgraded from version 0.82 to 0.84.
+
+C<run_forked> has various fixes/improvements, L<Socket> is only used where
+needed and a regression introduced in 0.78 has been fixed.
+
+=item *
+
+The libnet module collection has been upgraded from version 1.22 to 1.23.
+
+=item *
+
+L<List::Util> has been upgraded from version 1.27 to 1.30
+
+L<List::Util> now includes C<pairgrep>, C<pairmap>, C<pairs>, C<pairkeys>,
+C<pairvalues> and C<pairfirst> functions that operate on even-sized lists of
+pairs.
+
+=item *
+
+L<parent> has been upgraded from version 0.225 to 0.226.
+
+=item *
+
+L<Socket> has been upgraded from version 2.010 to 2.011.
+
+Handle FreeBSD (or other platforms) returning shorter AF_UNIX sockaddr
+structures due to embedded sun_len. [cpan #86613]
+
+=item *
+
+L<Storable> has been upgraded from version 2.45 to 2.46.
+
+Avoid creating temporary objects for STORABLE_attach when they aren't
+required. [perl #118907]
+
+=item *
+
+L<Time::Piece> has been upgraded from version 1.21 to 1.22.
=back
However, any changes to F<pod/perldiag.pod> should go in the L</Diagnostics>
section.
-=head3 L<perllocale>
-
-=over
-
-=item *
-
-Update to mention fc(), \F
-
-=back
-
-=head3 L<perltrap>
+=head3 L<perlopentut>
=over 4
=item *
-There is now a L<JavaScript|perltrap/JavaScript Traps> section.
+The C<open> tutorial has been completely rewriten by Tom Christiansen, and now
+focuses on covering only the basics, rather than providing a comprehensive
+reference to all things openable. This rewrite came as the result of a
+vigorous discussion on perl5-porters kicked off by a set of improvements
+written by Alexander Hartmaier to the existing C<perlopentut>. A "more than
+you ever wanted to know about C<open>" document may follow in subsequent
+versions of perl.
=back
=item *
-L<A sequence of multiple spaces in a charnames alias definition is deprecated|perldiag/"A sequence of multiple spaces in a charnames alias definition is deprecated">
-
-L<Trailing white-space in a charnames alias definition is deprecated|perldiag/"Trailing white-space in a charnames alias definition is deprecated">
-
-These two deprecation warnings involving C<\N{...}> were incorrectly
-implemented. They did not warn by default (now they do) and could not be
-made fatal via C<use warnings FATAL => 'deprecated'> (now they can).
+XXX L<message|perldiag/"message">
=back
entries for each change
Use L<XXX> with program names to get proper documentation linking. ]
-=head3 F<bisect.pl> enhancements
-
-The git bisection tool F<Porting/bisect.pl> has had many enhancements.
+=head3 L<XXX>
=over 4
=item *
-Can optionally run the test case with a timeout.
-
-=item *
-
-Can now run in-place in a clean git checkout.
-
-=item *
-
-Can run the test case under C<valgrind>.
-
-=item *
-
-Can apply user supplied patches and fixes to the source checkout before
-building.
-
-=item *
-
-Now has fixups to enable building several more historical ranges of bleadperl,
-which can be useful for pinpointing the origins of bugs or behaviour changes.
+XXX
=back
-It is provided as part of the source distribution but not installed because
-it is not self-contained as it relies on being run from within a git
-checkout. Note also that it makes no attempt to fix tests, correct runtime
-bugs or make something useful to install - its purpose is to make minimal
-changes to get any historical revision of interest to build and run as close
-as possible to "as-was", and thereby make C<git bisect> easy to use.
-
=head1 Configuration and Compilation
XXX Changes to F<Configure>, F<installperl>, F<installman>, and analogous tools
=over 4
-=item DG/UX
-
-DG/UX was a Unix sold by Data General. The last release was in April 2001.
-It only runs on Data General's own hardware.
-
=item XXX-some-platform
XXX
=over 4
-=item Mixed-endian platforms
-
-The code supporting C<pack> and C<unpack> operations on mixed endian
-platforms has been removed. We believe that Perl has long been unable to
-build on mixed endian architectures (such as PDP-11s), so we don't think
-that this change will affect any platforms which are able to build v5.18.0.
-
-=item Windows
-
-The BUILD_STATIC and ALL_STATIC makefile options for linking some or (nearly)
-all extensions statically (into perl519.dll, and into a separate
-perl-static.exe too) were broken for MinGW builds. This has now been fixed.
+=item XXX-some-platform
-The ALL_STATIC option has also been improved to include the Encode and Win32
-extensions (for both VC++ and MinGW builds).
+XXX
=back
significant internal changes for future core maintainers should be noted as
well.
-=over 4
-
-=item *
-
-Perl's new copy-on-write mechanism (which is now enabled by default),
-allows any C<SvPOK> scalar to be automatically upgraded to a copy-on-write
-scalar when copied. A reference count on the string buffer is stored in
-the string buffer itself.
-
-For example:
-
- $ perl -MDevel::Peek -e'$a="abc"; $b = $a; Dump $a; Dump $b'
- SV = PV(0x260cd80) at 0x2620ad8
- REFCNT = 1
- FLAGS = (POK,IsCOW,pPOK)
- PV = 0x2619bc0 "abc"\0
- CUR = 3
- LEN = 16
- COW_REFCNT = 1
- SV = PV(0x260ce30) at 0x2620b20
- REFCNT = 1
- FLAGS = (POK,IsCOW,pPOK)
- PV = 0x2619bc0 "abc"\0
- CUR = 3
- LEN = 16
- COW_REFCNT = 1
-
-Note that both scalars share the same PV buffer and have a COW_REFCNT
-greater than zero.
-
-This means that XS code which wishes to modify the C<SvPVX()> buffer of an
-SV should call C<SvPV_force()> or similar first, to ensure a valid (and
-unshared) buffer, and to call C<SvSETMAGIC()> afterwards. This in fact has
-always been the case (for example hash keys were already copy-on-write);
-this change just spreads the COW behaviour to a wider variety of SVs.
-
-One important difference is that before 5.18.0, shared hash-key scalars
-used to have the C<SvREADONLY> flag set; this is no longer the case.
-
-This new behaviour can still be disabled by running F<Configure> with
-B<-Accflags=-DPERL_NO_COW>. This option will probably be removed in Perl
-5.22.
-
-=item *
-
-C<PL_sawampersand> is now a constant. The switch this variable provided
-(to enable/disable the pre-match copy depending on whether C<$&> had been
-seen) has been removed and replaced with copy-on-write, eliminating a few
-bugs.
+[ List each change as a =item entry ]
-The previous behaviour can still be enabled by running F<Configure> with
-B<-Accflags=-DPERL_SAWAMPERSAND>.
-
-=item *
-
-The functions C<my_swap>, C<my_htonl> and C<my_ntohl> have been removed.
-It is unclear why these functions were ever marked as I<A>, part of the
-API. XS code can't call them directly, as it can't rely on them being
-compiled. Unsurprisingly, no code on CPAN references them.
-
-=item *
-
-The signature of the C<Perl_re_intuit_start()> regex function has changed;
-the function pointer C<intuit> in the regex engine plugin structure
-has also changed accordingly. A new parameter, C<strbeg> has been added;
-this has the same meaning as the same-named parameter in
-C<Perl_regexec_flags>. Previously intuit would try to guess the start of
-the string from the passed SV (if any), and would sometimes get it wrong
-(e.g. with an overloaded SV).
-
-=item *
-
-XS code may use various macros to change the case of a character or code
-point (for example C<toLOWER_utf8()>). Only a couple of these were
-documented until now;
-and now they should be used in preference to calling the underlying
-functions. See L<perlapi/Character case changing>.
+=over 4
=item *
-The code dealt rather inconsistently with uids and gids. Some
-places assumed that they could be safely stored in UVs, others
-in IVs, others in ints. Four new macros are introduced:
-SvUID(), sv_setuid(), SvGID(), and sv_setgid()
+C<sv_pos_b2u_flags> has been added to the API. It is similar to
+C<sv_pos_b2u>, but supports long strings on 64-bit platforms.
=back
=item *
-The OP allocation code now returns correctly aligned memory in all cases
-for C<struct pmop>. Previously it could return memory only aligned to a
-4-byte boundary, which is not correct for an ithreads build with 64 bit IVs
-on some 32 bit platforms. Notably, this caused the build to fail completely
-on sparc GNU/Linux. [RT #118055]
-
-=item *
-
-The debugger's C<man> command been fixed. It was broken in the v5.18.0
-release. The C<man> command is aliased to the names C<doc> and C<perldoc> -
-all now work again.
-
-=item *
-
-C<@_> is now correctly visible in the debugger, fixing a regression
-introduced in v5.18.0's debugger. [RT #118169]
-
-=item *
-
-Evaluating large hashes in scalar context is now much faster, as the number
-of used chains in the hash is now cached for larger hashes. Smaller hashes
-continue not to store it and calculate it when needed, as this saves one IV.
-That would be 1 IV overhead for every object built from a hash. [RT #114576]
-
-=item *
-
-Fixed a small number of regexp constructions that could either fail to
-match or crash perl when the string being matched against was
-allocated above the 2GB line on 32-bit systems. [RT #118175]
-
-=item *
-
-Perl v5.16 inadvertently introduced a bug whereby calls to XSUBs that were
-not visible at compile time were treated as lvalues and could be assigned
-to, even when the subroutine was not an lvalue sub. This has been fixed.
-[RT #117947]
-
-=item *
-
-In Perl v5.18.0 dualvars that had an empty string for the string part but a
-non-zero number for the number part starting being treated as true. In
-previous versions they were treated as false, the string representation
-taking precedeence. The old behaviour has been restored. [RT #118159]
-
-=item *
-
-Since Perl v5.12, inlining of constants that override built-in keywords of
-the same name had countermanded C<use subs>, causing subsequent mentions of
-the constant to use the built-in keyword instead. This has been fixed.
-
-=item *
-
-Lexical constants (C<my sub a() { 42 }>) no longer crash when inlined.
-
-=item *
-
-Parameter prototypes attached to lexical subroutines are now respected when
-compiling sub calls without parentheses. Previously, the prototypes were
-honoured only for calls I<with> parentheses. [RT #116735]
-
-=item *
-
-Syntax errors in lexical subroutines in combination with calls to the same
-subroutines no longer cause crashes at compile time.
-
-=item *
-
-The warning produced by C<-l $handle> now applies to IO refs and globs, not
-just to glob refs. That warning is also now UTF8-clean. [RT #117595]
-
-=item *
-
-Various memory leaks involving the parsing of the C<(?[...])> regular
-expression construct have been fixed.
+Autovivifying a subroutine stub via C<\&$glob> started causing crashes in
+Perl 5.18.0 if the $glob was merely a copy of a real glob, i.e., a scalar
+that had had a glob assigned to it. This has been fixed [perl #119051].
=item *
-C<(?[...])> now allows interpolation of precompiled patterns consisting of
-C<(?[...])> with bracketed character classes inside (C<$pat =
-S<qr/(?[ [a] ])/;> S</(?[ $pat ])/>>). Formerly, the brackets would
-confuse the regular expression parser.
+On 64-bit platforms C<pos> can now be set to a value higher than 2**31-1
+[perl #72766].
=item *
-The "Quantifier unexpected on zero-length expression" warning message could
-appear twice starting in Perl v5.10 for a regular expression also
-containing alternations (e.g., "a|b") triggering the trie optimisation.
+Perl used to leak an implementation detail when it came to referencing the
+return values of certain operators. C<for ($a+$b) { warn \$_; warn \$_ }>
+used to display two different memory addresses, because the C<\> operator
+was copying the variable. Under threaded builds, it would also happen for
+constants (C<for(1) { ... }>). This has been fixed [perl #21979, #78194,
+#89188, #109746, #114838, #115388].
=item *
-C<delete local $ENV{nonexistent_env_var}> no longer leaks memory.
+The range operator C<..> was returning the same modifiable scalars with
+each call, unless it was the only thing in a C<foreach> loop header. This
+meant that changes to values within the list returned would be visible the
+next time the operator was executed [perl #3105].
=item *
-C<sort> and C<require> followed by a keyword prefixed with C<CORE::> now
-treat it as a keyword, and not as a subroutine or module name. [RT #24482]
-
-=item *
-
-Through certain conundrums, it is possible to cause the current package to
-be freed. Certain operators (C<bless>, C<reset>, C<open>, C<eval>) could
-not cope and would crash. They have been made more resilient. [RT #117941]
-
-=item *
-
-Aliasing filehandles through glob-to-glob assignment would not update
-internal method caches properly if a package of the same name as the
-filehandle existed, resulting in filehandle method calls going to the
-package instead. This has been fixed.
-
-=item *
-
-C<./Configure -de -Dusevendorprefix> didn't default [RT #64126]
-
-=item *
-
-The C<Statement unlikely to be reached> warning was listed in
-L<perldiag> as an C<exec>-category warning, but was enabled and disabled
-by the C<syntax> category. On the other hand, the C<exec> category
-controlled its fatal-ness. It is now entirely handled by the C<exec>
-category.
-
-=item *
-
-Perl v5.18 inadvertently introduced a bug whereby interpolating mixed up-
-and down-graded UTF-8 strings in a regex could result in malformed UTF-8
-in the pattern: specifically if a downgraded character in the range
-C<\x80..\xff> followed a UTF-8 string, e.g.
-
- utf8::upgrade( my $u = "\x{e5}");
- utf8::downgrade(my $d = "\x{e5}");
- /$u$d/
-
-[RT #118297]
+Constant folding and subroutine inlining no longer cause operations that
+would normally return new modifiable scalars to return read-only values
+instead.
=back
XXX Generate this with:
- perl Porting/acknowledgements.pl v5.19.1..HEAD
+ perl Porting/acknowledgements.pl v5.19.2..HEAD
=head1 Reporting Bugs
https://perl5.git.perl.org / perl5.git / blobdiff