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perl-5.19.5
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NAME

perl5194delta - what is new for perl v5.19.4

DESCRIPTION

This document describes differences between the 5.19.3 release and the 5.19.4 release.

If you are upgrading from an earlier release such as 5.19.2, first read perl5193delta, which describes differences between 5.19.2 and 5.19.3.

Core Enhancements

rand now uses a consistent random number generator

Previously perl would use a platform specific random number generator, varying between the libc rand(), random() or drand48().

This meant that the quality of perl's random numbers would vary from platform to platform, from the 15 bits of rand() on Windows to 48-bits on POSIX platforms such as Linux with drand48().

Perl now uses its own internal drand48() implementation on all platforms. This does not make perl's rand cryptographically secure. [perl #115928]

Better 64-bit support

On 64-bit platforms, the internal array functions now use 64-bit offsets, allowing Perl arrays to hold more than 2**31 elements, if you have the memory available.

The regular expression engine now supports strings longer than 2**31 characters. [perl #112790, #116907]

The functions PerlIO_get_bufsiz, PerlIO_get_cnt, PerlIO_set_cnt and PerlIO_set_ptrcnt now have SSize_t, rather than int, return values and parameters.

New slice syntax

The new %hash{...} and %array[...] syntax returns a list of key/value (or index/value) pairs. See "Key/Value Hash Slices" in perldata.

EBCDIC support

Core Perl now mostly works on EBCDIC platforms. This is not true of many modules, including some which are shipped with this release. If you have resources to help continue this process, including test machines, send email to mailto:perl-mvs@perl.org.

As a result of this, certain XS functions are now deprecated; see "Internal Changes".

Incompatible Changes

Locale decimal point character no longer leaks outside of use locale scope (with the exception of $!)

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 use locale. However, until now under certain circumstances, the character used for a decimal point (often a comma) leaked outside the scope.

This continues the work released in Perl 5.19.1. It turns out that that did not catch all the leaks, including printf and sprintf not respecting use locale. If your code is affected by this change, simply add a use locale.

Now, the only known place where use locale is not respected is in the stringification of $!.

Assignments of Windows sockets error codes to $! now prefer errno.h values over WSAGetLastError() values

In previous versions of Perl, Windows sockets error codes as returned by WSAGetLastError() were assigned to $!, and some constants such as ECONNABORTED, not in errno.h in VC++ (or the various Windows ports of gcc) were defined to corresponding WSAE* values to allow $! to be tested against the E* constants exported by Errno and POSIX.

This worked well until VC++ 2010 and later, which introduced new E* constants with values > 100 into errno.h, including some being (re)defined by perl to WSAE* values. That caused problems when linking XS code against other libraries which used the original definitions of errno.h constants.

To avoid this incompatibility, perl now maps WSAE* error codes to E* values where possible, and assigns those values to $!. The E* constants exported by Errno and POSIX are updated to match so that testing $! against them, wherever previously possible, will continue to work as expected, and all E* constants found in errno.h are now exported from those modules with their original errno.h values

In order to avoid breakage in existing Perl code which assigns WSAE* values to $!, perl now intercepts the assignment and performs the same mapping to E* values as it uses internally when assigning to $! itself.

However, one backwards-incompatibility remains: existing Perl code which compares $! against the numeric values of the WSAE* error codes that were previously assigned to $! will now be broken in those cases where a corresponding E* value has been assigned instead. This is only an issue for those E* values < 100, which were always exported from Errno and POSIX with their original errno.h values, and therefore could not be used for WSAE* error code tests (e.g. WSAEINVAL is 10022, but the corresponding EINVAL is 22). (E* values > 100, if present, were redefined to WSAE* values anyway, so compatibility can be achieved by using the E* constants, which will work both before and after this change, albeit using different numeric values under the hood.)

Deprecations

Literal control characters in variable names

This deprecation affects things like $\cT, where \cT is a literal control in the source code. Surprisingly, it appears that originally this was intended as the canonical way of accessing variables like $^T, with the caret form only being added as an alternative.

The literal control form is being deprecated for two main reasons. It has what are likely unfixable bugs, such as $\cI not working as an alias for $^I, and their usage not being portable to non-ASCII platforms: While $^T will work everywhere, \cT is whitespace in EBCDIC. [perl #119123]

Performance Enhancements

  • The trie performance enhancement for regular expressions has now been extended to those compiled under /iaa.

Modules and Pragmata

Updated Modules and Pragmata

  • autodie has been upgraded from version 2.20 to 2.21.

    Numerous improvements have been made, many speed-related. See the Changes file in the CPAN distribution for full details.

  • B has been upgraded from version 1.45 to 1.46.

    The fix for [perl #118525] introduced a regression in the behaviour of B::CV::GV, changing the return value from a B::SPECIAL object on a NULL CvGV to undef. B::CV::GV again returns a B::SPECIAL object in this case. [perl #119351]

    B version 1.44 (Perl 5.19.2) introduced four new B::OP methods, slabbed, savefree, static and folded, but these have never actually worked until now. They used to croak.

  • B::Concise has been upgraded from version 0.98 to 0.99.

    The handling of the glob operator, broken since Perl 5.17.6, has been fixed and handling of the new kvaslice and kvhslice operators have been added.

  • B::Deparse has been upgraded from version 1.22 to 1.23.

    The new kvaslice and kvhslice operators have been added.

  • Carp has been upgraded from version 1.31 to 1.32.

    • In stack traces, subroutine arguments that are strings are now quoted in a consistent manner, regardless of what characters they contain and how they're internally represented.

    • Carp also now shows subroutine arguments that are references to regexp objects in a consistent manner in stack traces.

    • Carp now takes care not to clobber the status variables $! and $^E.

    • Carp now won't vivify the overload::StrVal glob or subroutine or the overload stash.

    • Carp now avoids some unwanted Unicode warnings on older Perls. This doesn't affect behaviour with current Perls.

    • Carp::Heavy detects version mismatch with Carp, to give a good error message if a current (stub) Carp::Heavy gets loaded by an old Carp that expects Carp::Heavy to provide subroutines.

  • charnames has been upgraded from version 1.38 to 1.39.

    This module now works on EBCDIC platforms.

  • CPAN has been upgraded from version 2.00 to 2.03-TRIAL.

    Numerous updates and bug fixes are incorporated. See the Changes file for full details.

  • CPAN::Meta has been upgraded from version 2.132140 to 2.132620.

    META validation no longer allows a scalar value when a list was required for a field.

  • CPAN::Meta::Requirements has been upgraded from version 2.122 to 2.123.

    No changes have been made to the installed code other than the version bump to keep in sync with the latest CPAN release.

  • Data::Dumper has been upgraded from version 2.148 to 2.149.

    This upgrade is part of a larger change to make the array interface 64-bit safe by using SSize_t instead of I32 for array indices.

    In addition, an EBCDIC fix has been applied.

  • Devel::Peek has been upgraded from version 1.13 to 1.14.

    This upgrade is part of a larger change to preserve referential identity when passing undef to a subroutine by using NULL rather than &PL_sv_undef for non-existent array elements.

    In addition, Dump with no args was broken in Perl 5.19.3, but has now been fixed.

  • diagnostics has been upgraded from version 1.32 to 1.33.

    =back is now treated as the end of a warning description, thus keeping any trailing data in the file from showing up as part of the last warning's description. [perl #119817]

  • DynaLoader has been upgraded from version 1.19 to 1.20.

    The documentation now makes it clear, as has always been the case, that dl_unload_file is only called automatically to unload all loaded shared objects if the perl interpreter was built with the C macro DL_UNLOAD_ALL_AT_EXIT defined. Support for GNU DLD has also been removed.

  • Encode has been upgraded from version 2.52 to 2.55.

    An erroneous early return in decode_utf8 has been removed, and a bug in _utf8_on under COW has been fixed. Encode also now uses parent rather than base throughout.

  • Errno has been upgraded from version 1.19 to 1.20.

    The list of E* constants exported on Windows has been updated to reflect the changes made in the assignment of sockets error codes to $! (see "Incompatible Changes").

  • Exporter has been upgraded from version 5.69 to 5.70.

    A number of typos have been corrected in the documentation.

  • ExtUtils::CBuilder has been upgraded from version 0.280210 to 0.280212.

    No changes have been made to the installed code other than the version bump to keep in sync with the latest CPAN release.

  • ExtUtils::Command has been upgraded from version 1.17 to 1.18.

    No changes have been made to the installed code other than the version bump to keep in sync with the latest CPAN release.

  • ExtUtils::MakeMaker has been upgraded from version 6.72 to 6.76.

    Numerous updates and bug fixes are incorporated. See the Changes file for full details.

  • ExtUtils::ParseXS has been upgraded from version 3.21 to 3.23.

    Unquoted "here-doc" markers for typemaps can now be optionally followed by a semicolon, just like quoted markers. [perl #119761]

  • File::Copy has been upgraded from version 2.27 to 2.28.

    The documentation of copy now makes it clear that trying to copy a file into a non-existent directory is not supported. [perl #119539]

  • File::Find has been upgraded from version 1.24 to 1.25.

    Better diagnostics are now provided in the case of a failed chdir.

  • File::Glob has been upgraded from version 1.20 to 1.21.

    glob now warns in the context of use warnings "syscalls"; if the supplied pattern has an internal NUL ("\0") character.

  • FileCache has been upgraded from version 1.08 to 1.09.

    This upgrade is part of a larger change to use parent rather than base.

  • Hash::Util::FieldHash has been upgraded from version 1.12 to 1.13.

    This upgrade is part of a larger change to use parent rather than base.

  • HTTP::Tiny has been upgraded from version 0.034 to 0.035.

    Encoded data from post_form now preserves term order if data is provided as an array reference. (They are still sorted for consistency if provided as a hash reference.)

  • I18N::LangTags has been upgraded from version 0.39 to 0.40.

    Bosnian has now joined Croatian and Serbian in the lists of mutually intelligible Slavic languages. [perl #72594]

  • IO has been upgraded from version 1.28 to 1.29.

    A minor internals-only change has been made to the XS code.

  • IO::Socket has been upgraded from version 1.36 to 1.37.

    The connect method has been updated in the light of changes made in the assignment of sockets error codes to $! on Windows (see "Incompatible Changes").

  • IPC::Open3 has been upgraded from version 1.15 to 1.16.

    This upgrade is part of a larger change to preserve referential identity when passing undef to a subroutine by using NULL rather than &PL_sv_undef for non-existent array elements.

  • JSON::PP has been patched from version 2.27202 to 2.27202_01.

    A precedence issue has been fixed in the return value of a private subroutine.

  • Locale::Codes has been upgraded from version 3.26 to 3.27.

    New codes have been added and the (deprecated) set of FIPS-10 country codes has been removed.

  • Math::BigInt has been upgraded from version 1.9992 to 1.9993.

    Cleaned up the Math::BigInt and Math::BigFloat documentation to be more consistent with other Perl documentation. [perl #86686]

    Added a bint method for rounding towards zero. [perl #85296]

  • Math::BigInt::FastCalc has been upgraded from version 0.30 to 0.31.

    This upgrade is part of a larger change to make the array interface 64-bit safe by using SSize_t instead of I32 for array indices.

  • Module::CoreList has been upgraded from version 2.97 to 2.99.

    The list of Perl versions covered has been updated.

    A function is_core has been added, which returns true if the specified module was bundled with Perl. Optionally you can specify a minimum version of the module, and the specific version of Perl you're interested in (defaults to $^V, the running version of Perl).

  • Module::Load::Conditional has been upgraded from version 0.54 to 0.58.

    requires has been made more robust. [cpan #83728]

  • Module::Metadata has been upgraded from version 1.000014 to 1.000018.

    The module's DESCRIPTION has been re-worded regarding safety/security to satisfy CVE-2013-1437. Also, versions are now detainted if needed. [cpan #88576]

  • mro has been upgraded from version 1.13 to 1.14.

    This upgrade is part of a larger change to make the array interface 64-bit safe by using SSize_t instead of I32 for array indices.

  • Opcode has been upgraded from version 1.25 to 1.26.

    The new kvaslice and kvhslice operators have been added.

  • parent has been upgraded from version 0.226 to 0.228.

    No changes have been made to the installed code other than the version bump to keep in sync with the latest CPAN release.

  • Parse::CPAN::Meta has been upgraded from version 1.4405 to 1.4407.

    No changes have been made to the installed code other than the version bump to keep in sync with the latest CPAN release.

  • Perl::OSType has been upgraded from version 1.003 to 1.005.

    The Unix OSType 'bitrig' has been added.

  • perlfaq has been upgraded from version 5.0150043 to 5.0150044.

    The use of gensym in a number of examples has been removed, the use of & in subroutine calls is now clarified and several new questions have been answered.

  • Pod::Html has been upgraded from version 1.20 to 1.21.

    This upgrade is part of a larger change to use parent rather than base.

  • POSIX has been upgraded from version 1.34 to 1.35.

    The list of E* constants exported on Windows has been updated to reflect the changes made in the assignment of sockets error codes to $! (see "Incompatible Changes").

  • re has been upgraded from version 0.25 to 0.26.

    This upgrade is part of a larger change to support 64-bit string lengths in the regular expression engine.

  • Scalar::Util has been upgraded from version 1.31 to 1.32.

    The documentation of blessed has been improved to mention the fact that package "0" is defined but false.

  • Socket has been upgraded from version 2.011 to 2.012.

    Syntax errors when building on the WinCE platform have been fixed. [cpan #87389]

  • Storable has been upgraded from version 2.46 to 2.47.

    This upgrade is part of a larger change to preserve referential identity when passing undef to a subroutine by using NULL rather than &PL_sv_undef for non-existent array elements.

  • Term::ReadLine has been upgraded from version 1.13 to 1.14.

    Term::ReadLine::EditLine support has been added.

  • Test::Simple has been patched from version 0.98 to 0.98_06.

    A precedence issue has been fixed in the return value of a private subroutine in Test::Builder.

  • Time::Piece has been upgraded from version 1.22 to 1.23.

    Day of year parsing (like "%y%j") has been fixed.

  • Unicode::Collate has been upgraded from version 0.98 to 0.99.

    By default, out-of-range values are replaced with U+FFFD (REPLACEMENT CHARACTER) when UCA_Version >= 22, or ignored when UCA_Version <= 20. When UCA_Version >= 22, the weights of out-of-range values can be overridden.

  • Unicode::UCD has been upgraded from version 0.53 to 0.54.

    This module now works on EBCDIC platforms.

  • version has been upgraded from version 0.9903 to 0.9904.

    No changes have been made to the installed code other than the version bump to keep in sync with the latest CPAN release.

  • warnings has been upgraded from version 1.18 to 1.19.

    The syscalls warnings category has been added to check for embedded NUL ("\0") characters in pathnames and string arguments to other system calls. [perl #117265]

  • XS::Typemap has been upgraded from version 0.10 to 0.11.

    This upgrade is part of the change to remove the uninitialized warnings exemption for uninitialized values returned by XSUBs (see the "Selected Bug Fixes" section).

Documentation

New Documentation

perlrepository

This document was removed (actually, renamed perlgit and given a major overhaul) in Perl 5.13.10, causing Perl documentation websites to show the now out of date version in Perl 5.12 as the latest version. It has now been restored in stub form, directing readers to current information.

Changes to Existing Documentation

perldata

  • New sections have been added to document the new index/value array slice and key/value hash slice syntax.

perldebguts

  • The DB::goto and DB::lsub debugger subroutines are now documented. [perl #77680]

perlguts

  • Numerous minor changes have been made to reflect changes made to the perl internals in this release.

perlhack

perlsub

  • A list of subroutine names used by the perl implementation is now included. [perl #77680]

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

New Errors

New Warnings

  • Invalid \0 character in %s for %s: %s\0%s

    (W syscalls) Embedded \0 characters in pathnames or other system call arguments produce a warning as of 5.20. The parts after the \0 were formerly ignored by system calls.

  • Possible precedence issue with control flow operator

    (W syntax) There is a possible problem with the mixing of a control flow operator (e.g. return) and a low-precedence operator like or. Consider:

    sub { return $a or $b; }

    This is parsed as:

    sub { (return $a) or $b; }

    Which is effectively just:

    sub { return $a; }

    Either use parentheses or the high-precedence variant of the operator.

    Note this may be also triggered for constructs like:

    sub { 1 if die; }

  • Scalar value %%s[%s] better written as $%s[%s]

    (W syntax) In scalar context, you've used an array index/value slice (indicated by %) to select a single element of an array. Generally it's better to ask for a scalar value (indicated by $). The difference is that $foo[&bar] always behaves like a scalar, both in the value it returns and when evaluating its argument, while %foo[&bar] provides a list context to its subscript, which can do weird things if you're expecting only one subscript. When called in list context, it also returns the index (what &bar returns) in addition to the value.

  • Scalar value %%s{%s} better written as $%s{%s}

    (W syntax) In scalar context, you've used a hash key/value slice (indicated by %) to select a single element of a hash. Generally it's better to ask for a scalar value (indicated by $). The difference is that $foo{&bar} always behaves like a scalar, both in the value it returns and when evaluating its argument, while @foo{&bar} and provides a list context to its subscript, which can do weird things if you're expecting only one subscript. When called in list context, it also returns the key in addition to the value.

  • Use of literal control characters in variable names is deprecated

    (D deprecated) Using literal control characters in the source to refer to the ^FOO variables, like $^X and ${^GLOBAL_PHASE} is now deprecated. This only affects code like $\cT, where \cT is a control in the source code: ${"\cT"} and $^T remain valid.

Changes to Existing Diagnostics

  • Warnings and errors from the regexp engine are now UTF-8 clean

  • The "Unknown switch condition" error message has some slight changes. This error triggers when there is an unknown condition in a (?(foo)) conditional. The error message used to read:

    Unknown switch condition (?(%s in regex;

    But what %s could be was mostly up to luck. For (?(foobar)), you might have seen "fo" or "f". For Unicode characters, you would generally get a corrupted string. The message has been changed to read:

    Unknown switch condition (?(...)) in regex;

    Additionally, the '<-- HERE' marker in the error will now point to the correct spot in the regex.

  • The "%s "\x%X" does not map to Unicode" warning is now correctly listed as a severe warning rather than as a fatal error.

Utility Changes

find2perl

  • find2perl now handles ? wildcards correctly. [perl #113054]

Configuration and Compilation

  • The Makefile.PL for SDBM_File now generates a better Makefile, which avoids a race condition during parallel makes, which could cause the build to fail. This is the last known parallel make problem (on *nix platforms), and therefore we believe that a parallel make should now always be error free.

    Strictly only for a build where build files such as Makefile.SH have not been updated by git in an already configured and built tree.

Testing

  • The test script t/bigmem/regexp.t has been added to test that regular expression matches on very large strings now succeed as expected.

  • A bug that was fixed in Perl 5.15.4 is now tested by the new test script t/io/eintr_print.t. [perl #119097]

  • The new test scripts t/op/kvaslice.t and t/op/kvhslice.t test the new index/value array slice and key/value hash slice syntax respectively.

  • Various cases of die, last, goto and exit triggering DESTROY are now tested by the new test script t/op/rt119311.t.

  • The new test script t/op/waitpid.t tests the fix for [perl #85228] (see "Selected Bug Fixes").

  • The latest copyright years in the top-level README file and the perl -v output are now tested as matching each other by the new test script t/porting/copyright.t

  • The new test script t/win32/signal.t tests that $! and $^E are now preserved across signal handlers by the Win32 signal emulation code.

  • The test script t/x2p/find2perl.t has been added to test the find2perl program on platforms where it is practical to do so.

Platform Support

New Platforms

FreeMiNT

Support has been added for FreeMiNT, a free open-source OS for the Atari ST system and its successors, based on the original MiNT that was officially adopted by Atari.

Bitrig

Compile support has been added for Bitrig, a fork of OpenBSD.

Discontinued Platforms

Configure hints and conditional code for several very old platforms has been removed. We have not received reports for these in many years, typically not since Perl 5.6.0.

AT&T 3b1

Configure support for the 3b1, also known as the AT&T Unix PC (and the similar AT&T 7300), has been removed.

Platform-Specific Notes

VMS

The PERL_ENV_TABLES feature to control the population of %ENV at perl start-up was broken in Perl 5.16.0 but has now been fixed.

Win32

rename and link on Win32 now set $! to ENOSPC and EDQUOT when appropriate. [perl #119857]

WinCE

Perl now builds again on WinCE, following locale-related breakage (WinCE has non-existent locale support) introduced around 5.19.1. [perl #119443]

The building of XS modules has largely been restored. Several still cannot (yet) be built but it is now possible to build Perl on WinCE with only a couple of further patches (to Socket and ExtUtils::MakeMaker), hopefully to be incorporated soon.

GNU/Hurd

The BSD compatibility library libbsd is no longer required for builds.

Internal Changes

  • The internal representation has changed for the match variables $1, $2 etc., $`, $&, $', ${^PREMATCH}, ${^MATCH} and ${^POSTMATCH}. It uses slightly less memory, avoids string comparisons and numeric conversions during lookup, and uses 23 fewer lines of C. This change should not affect any external code.

  • Arrays now use NULL internally to represent unused slots, instead of &PL_sv_undef. &PL_sv_undef is no longer treated as a special value, so av_store(av, 0, &PL_sv_undef) will cause element 0 of that array to hold a read-only undefined scalar. $array[0] = anything will croak and \$array[0] will compare equal to \undef.

  • The SV returned by HeSVKEY_force() now correctly reflects the UTF8ness of the underlying hash key when that key is not stored as a SV. [perl #79074]

  • Certain rarely used functions and macros available to XS code are now, or are planned to be, deprecated. These are: utf8n_to_uvuni (use utf8_to_uvchr_buf instead), utf8_to_uni_buf (use utf8_to_uvchr_buf instead), valid_utf8_to_uvuni (use utf8_to_uvchr_buf instead), uvuni_to_utf8 (use uvchr_to_utf8 instead), NATIVE_TO_NEED (this did not work properly anyway), and ASCII_TO_NEED (this did not work properly anyway).

    Starting in this release, almost never does application code need to distinguish between the platform's character set and Latin1, on which the lowest 256 characters of Unicode are based.

Selected Bug Fixes

  • The value of $^E is now saved across signal handlers on Windows. [perl #85104]

  • A lexical filehandle (as in open my $fh...) is usually given a name based on the current package and the name of the variable, e.g. "main::$fh". Under recursion, the filehandle was losing the "$fh" part of the name. This has been fixed.

  • Perl 5.19.3 accidentally extended the previous bug to all closures, even when not called recursively, i.e. lexical handles in closure would always be called "main::" or "MyPackage::" etc. This has been fixed.

  • Uninitialized values returned by XSUBs are no longer exempt from uninitialized warnings. [perl #118693]

  • elsif ("") no longer erroneously produces a warning about void context. [perl #118753]

  • Passing undef to a subroutine now causes @_ to contain the same read-only undefined scalar that undef returns. Furthermore, exists $_[0] will now return true if undef was the first argument. [perl #7508, #109726]

  • Passing a non-existent array element to a subroutine does not usually autovivify it unless the subroutine modifies its argument. This did not work correctly with negative indices and with non-existent elements within the array. The element would be vivified immediately. The delayed vivification has been extended to work with those. [perl #118691]

  • Assigning references or globs to the scalar returned by $#foo after the @foo array has been freed no longer causes assertion failures on debugging builds and memory leaks on regular builds.

  • Perl 5.19.2 threw line numbers off after some cases of line breaks following keywords, such as

    1 unless
1;

    This has been fixed. [perl #118931]

  • On 64-bit platforms, large ranges like 1..1000000000000 no longer crash, but eat up all your memory instead. [perl #119161]

  • __DATA__ now puts the DATA handle in the right package, even if the current package has been renamed through glob assignment.

  • The string position set by pos could shift if the string changed representation internally to or from utf8. This could happen, e.g., with references to objects with string overloading.

  • Taking references to the return values of two pos calls with the same argument, and then assigning a reference to one and undef to the other, could result in assertion failures or memory leaks.

  • Elements of @- and @+ now update correctly when they refer to non-existent captures. Previously, a referenced element ($ref = \$-[1]) could refer to the wrong match after subsequent matches.

  • When die, last, next, redo, goto and exit unwind the scope, it is possible for DESTROY recursively to call a subroutine or format that is currently being exited. It that case, sometimes the lexical variables inside the sub would start out having values from the outer call, instead of being undefined as they should. This has been fixed. [perl #119311]

  • ${^MPEN} is no longer treated as a synonym for ${^MATCH}.

  • Perl now tries a little harder to return the correct line number in (caller)[2]. [perl #115768]

  • Line numbers inside multiline quote-like operators are now reported correctly. [perl #3643]

  • #line directives inside code embedded in quote-like operators are now respected.

  • Line numbers are now correct inside the second here-doc when two here-doc markers occur on the same line.

  • Starting with Perl 5.12, line numbers were off by one if the -d switch was used on the #! line. Now they are correct.

  • Perl 5.19.2 inadvertently stopped some lines of code from being available to the debugger if => occurred at the beginning of a line and the previous line ended with a keyword. This is now fixed.

  • Perl 5.19.2 allowed the PERL5DB environment variable to contain multiple lines of code, but those lines were not made available to the debugger. Now they are all stuffed into line number 0, accessible via $dbline[0] in the debugger.

  • An optimization in Perl 5.18 made incorrect assumptions causing a bad interaction with the Devel::CallParser CPAN module. If the module was loaded then lexical variables declared in separate statements following a my(...) list might fail to be cleared on scope exit.

  • &xsub and goto &xsub calls now allow the called subroutine to autovivify elements of @_.

  • &xsub and goto &xsub no longer crash if *_ has been undefined and has no ARRAY entry (i.e. @_ does not exist).

  • &xsub and goto &xsub now work with tied @_.

  • Overlong identifiers no longer cause a buffer overflow (and a crash). They started doing so in Perl 5.18.

  • The warning "Scalar value @hash{foo} better written as $hash{foo}" now produces far fewer false positives. In particular, @hash{+function_returning_a_list} and @hash{ qw "foo bar baz" } no longer warn. The same applies to array slices. [perl #28380, #114024]

  • $! = EINVAL; waitpid(0, WNOHANG); no longer goes into an internal infinite loop. [perl #85228]

  • Perl 5.19.3 accidentally caused \(1+2) to return a reference to the same mutable scalar each time, so that modifications affect future evaluations. This has been fixed. [perl #119501]

  • A possible segmentation fault in filehandle duplication has been fixed.

  • A subroutine in @INC can return a reference to a scalar containing the initial contents of the file. However, that scalar was freed prematurely if not referenced elsewhere, giving random results.

Acknowledgements

Perl 5.19.4 represents approximately 4 weeks of development since Perl 5.19.3 and contains approximately 31,000 lines of changes across 580 files from 42 authors.

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 5.19.4:

Andy Dougherty, Brian Fraser, Chris 'BinGOs' Williams, Christian Millour, Craig A. Berry, Daniel Dragan, David Golden, David Leadbeater, David Mitchell, Father Chrysostomos, Florian Ragwitz, François Perrad, H.Merijn Brand, James E Keenan, John Goodyear, John P. Linderman, John Peacock, Karl Williamson, kevin dawson, Leon Timmermans, Marco Peereboom, Matthew Horsfall, Nathan Glenn, Neil Bowers, Nicholas Clark, Niels Thykier, Niko Tyni, Owain G. Ainsworth, Peter John Acklam, Reini Urban, Ricardo Signes, Ruslan Zakirov, Slaven Rezic, Smylers, Steve Hay, Sullivan Beck, Toby Inkster, Tokuhiro Matsuno, Tony Cook, Victor Efimov, Zefram, Zsbán Ambrus.

The list above is almost certainly incomplete as it is automatically generated from version control history. In particular, it does not include the names of the (very much appreciated) contributors who reported issues to the Perl bug tracker.

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.

For a more complete list of all of Perl's historical contributors, please see the AUTHORS file in the Perl source distribution.

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 will 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.