- NAME
- DESCRIPTION
- Security
  - Hash iteration randomized per hash variable
- Incompatible Changes
  - Explicit rules for variable names and identifiers
- Deprecations
  - PL_sv_objcount
- Modules and Pragmata
  - New Modules and Pragmata
  - Updated Modules and Pragmata
- Documentation
  - Changes to Existing Documentation
    - "\N" in perlrebackslash
- Diagnostics
  - New Diagnostics
    - New Warnings
  - Changes to Existing Diagnostics
- Internal Changes
- Selected Bug Fixes
- Acknowledgements
- Reporting Bugs
- SEE ALSO

# utf8NAME

perldelta - what is new for perl v5.17.10

# DESCRIPTION

This document describes differences between the 5.17.9 release and the 5.17.10 release.

If you are upgrading from an earlier release such as 5.17.8, first read perl5179delta, which describes differences between 5.17.8 and 5.17.9.

# Security

## Hash iteration randomized per hash variable

Every hash has its own iteration order, which should make it much more difficult to determine what the current hash seed is.

# Incompatible Changes

## Explicit rules for variable names and identifiers

Due to an oversight, length-one variable names in 5.16 were completely unrestricted, and opened the door to several kinds of insanity. As of 5.18, these now follow the rules of other identifiers, in addition to accepting characters that match the \p{POSIX_Punct} property.

There are no longer any differences in the parsing of identifiers specified as $... or ${...}; previously, they were dealt with in different parts of the core, and so had slightly different behavior. For instance, `${foo:bar}` was a legal variable name. Since they are now both parsed by the same code, that is no longer the case.

[ List each incompatible change as a =head2 entry ]

# Deprecations

## PL_sv_objcount

This interpreter-global variable used to track the total number of Perl objects in the interpreter. It is no longer maintained and will be removed altogether in Perl 5.20.

# Modules and Pragmata

## New Modules and Pragmata

- Config::Perl::V 0.17 has been added to the Perl core.

## Updated Modules and Pragmata

- Archive::Extract has been upgraded from version 0.62 to 0.68.

  NOTE: Archive::Extract is deprecated and may be removed from a future version of Perl.

- Attribute::Handlers has been upgraded from version 0.93 to 0.94.

- B::Lint has been upgraded from version 1.14 to 1.17.

  NOTE: B::Lint is deprecated and may be removed from a future version of Perl.

- Benchmark has been upgraded from version 1.14 to 1.15.

  This reverts (for now) a change in 1.14 whereby the "too few iterations" message became a warning on STDERR instead of being output on STDOUT. It's now on STDOUT again.

- bignum has been upgraded from version 0.31 to 0.32.

- CPAN has been upgraded from version 1.99_51 to 2.00.

- CPANPLUS has been upgraded from version 0.9133 to 0.9135.

  NOTE: CPANPLUS is deprecated and may be removed from a future version of Perl.

- CPANPLUS::Dist::Build has been upgraded from version 0.68 to 0.70.

  NOTE: CPANPLUS::Dist::Build is deprecated and may be removed from a future version of Perl.

- Data::Dumper has been upgraded from version 2.141 to 2.142.

- DBM_Filter has been upgraded from version 0.04 to 0.05.

- Digest::SHA has been upgraded from version 5.81 to 5.82.

- Encode has been upgraded from version 2.47 to 2.48.

- ExtUtils::Manifest has been upgraded from version 1.62 to 1.63.

- File::CheckTree has been upgraded from version 4.41 to 4.42.

- File::DosGlob has been upgraded from version 1.09 to 1.10.

- File::Temp has been upgraded from version 0.22 to 0.22_90.

- Filter::Simple has been upgraded from version 0.88 to 0.89.

- IO has been upgraded from version 1.26 to 1.27.

- Log::Message has been upgraded from version 0.04 to 0.06.

  NOTE: Log::Message is deprecated and may be removed from a future version of Perl.

- Log::Message::Simple has been upgraded from version 0.08 to 0.10.

  NOTE: Log::Message::Simple is deprecated and may be removed from a future version of Perl.

- Math::BigInt has been upgraded from version 1.998 to 1.999.

- Module::CoreList has been upgraded from version 2.80 to 2.85.

- Module::Load has been upgraded from version 0.22 to 0.24.

- Module::Pluggable has been upgraded from version 4.5 to 4.6.

  NOTE: Module::Pluggable is deprecated and may be removed from a future version of Perl.

- Net::Ping has been upgraded from version 2.39 to 2.41.

  This fixes some test failures on Windows.

- Object::Accessor has been upgraded from version 0.44 to 0.46.

  NOTE: Object::Accessor is deprecated and may be removed from a future version of Perl.

- overload has been upgraded from version 1.20 to 1.21.

- Perl::OSType has been upgraded from version 1.002 to 1.003.

  This fixes a bug detecting the VOS operating system.

- PerlIO::scalar has been upgraded from version 0.15 to 0.16.

- Pod::Checker has been upgraded from version 1.51 to 1.60.

- Pod::Html has been upgraded from version 1.17 to 1.18.

- Pod::Parser has been upgraded from version 1.51 to 1.60.

- Pod::Perldoc has been upgraded from version 3.17 to 3.19.

- Pod::Usage has been upgraded from version 1.51 to 1.61.

- SelfLoader has been upgraded from version 1.20 to 1.21.

- Term::UI has been upgraded from version 0.32 to 0.34.

  NOTE: Term::UI is deprecated and may be removed from a future version of Perl.

- Test::Harness has been upgraded from version 3.25_01 to 3.26.

- Text::Soundex has been upgraded from version 3.03_01 to 3.04.

- Thread::Queue has been upgraded from version 3.01 to 3.02.

- Unicode::UCD has been upgraded from version 0.47 to 0.50.

- warnings has been upgraded from version 1.16 to 1.17.

- Win32 has been upgraded from version 0.45 to 0.46.

- Win32API::File has been upgraded from version 0.1200 to 0.1201.

# Documentation

## Changes to Existing Documentation

### "\N" in perlrebackslash

- This feature is no longer experimental.

# 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 Warnings

- %c* is deprecated, and will become a syntax error

  Use of `@*`, `&*`, `**` or `%*` is now deprecated, and will generate a compile time warning, enabled by default. In future such code will fail to compile with a syntax error. Removing these variables, along with `$*`, will permit future syntax additions.

## Changes to Existing Diagnostics

- $* is no longer supported, and will become a syntax error

  The warning that use of `$*` and `$#` is no longer supported is now generated for every location that references them. Previously it would fail to be generated if another variable using the same typeglob was seen first (e.g. `@*` before `$*`), and would not be generated for the second and subsequent uses. (It's hard to fix the failure to generate warnings at all without also generating them every time, and warning every time is consistent with the warnings that `$[` used to generate.)

# Internal Changes

- The new copy-on-write mechanism that was introduced in 5.17.7 has now been disabled by default, since it was felt that there were too many rough edges for the 5.18 release. It is expected that it will be enabled by default for 5.20.

  This change also re-enables PL_sawampersand by default.

  It can be enabled in a perl build by running Configure with -Accflags=-DPERL_NEW_COPY_ON_WRITE, and we would encourage XS authors to try their code with such an enabled perl, and provide feedback. XXX need blurb, e.g. a reference to a new section in perlguts or perlxs explaining how XS authors should handle COW strings.

# Selected Bug Fixes

- Fix two crashes in the debugger when using Frame=2 or autotrace. These are [perl #116769] and [perl #116771].

# Acknowledgements

Perl 5.17.10 represents approximately 4 weeks of development since Perl 5.17.9 and contains approximately 77,000 lines of changes across 440 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 5.17.10:

Aaron Crane, Aaron Trevena, Andrew Tam, Andy Dougherty, Anton Nikishaev, Brad Gilbert, Brian Fraser, Charlie Gonzalez, Chris 'BinGOs' Williams, Craig A. Berry, Daniel Dragan, David Golden, David Mitchell, Dominic Hargreaves, Florian Ragwitz, George Greer, H.Merijn Brand, James E Keenan, Jasmine Ahuja, John Goodyear, John Peacock, Karl Williamson, Kent Fredric, Lukas Mai, Max Maischein, Nicholas Clark, Patrik Hägglund, Paul Green, Peter Martini, Rafael Garcia-Suarez, Renee Baecker, Ricardo Signes, Ruslan Zakirov, Salvador Fandiño, Scott Lanning, Shirakata Kentaro, Steffen Müller, Steve Hay, Steve Peters, Sullivan Beck, Tony Cook, Yves Orton.

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.