Ubuntu Manpage: perl5243delta - what is new for perl v5.24.3

Provided by: perl-doc_5.38.2-3.2ubuntu0.1_all

NAME

       perl5243delta - what is new for perl v5.24.3

DESCRIPTION

       This document describes differences between the 5.24.2 release and the 5.24.3 release.

       If you are upgrading from an earlier release such as 5.24.1, first read perl5242delta, which describes
       differences between 5.24.1 and 5.24.2.

Security

   [CVE-2017-12837] Heap buffer overflow in regular expression compiler
       Compiling certain regular expression patterns with the case-insensitive modifier could cause a heap
       buffer overflow and crash perl.  This has now been fixed.  [GH #16021]
       <https://github.com/Perl/perl5/issues/16021>

   [CVE-2017-12883] Buffer over-read in regular expression parser
       For certain types of syntax error in a regular expression pattern, the error message could either contain
       the contents of a random, possibly large, chunk of memory, or could crash perl.  This has now been fixed.
       [GH #16025] <https://github.com/Perl/perl5/issues/16025>

   [CVE-2017-12814] $ENV{$key} stack buffer overflow on Windows
       A possible stack buffer overflow in the %ENV code on Windows has been fixed by removing the buffer
       completely since it was superfluous anyway.  [GH #16051] <https://github.com/Perl/perl5/issues/16051>

Incompatible Changes

       There are no changes intentionally incompatible with 5.24.2.  If any exist, they are bugs, and we request
       that you submit a report.  See "Reporting Bugs" below.

Modules and Pragmata

   Updated Modules and Pragmata
       •   Module::CoreList has been upgraded from version 5.20170715_24 to 5.20170922_24.

       •   POSIX has been upgraded from version 1.65 to 1.65_01.

       •   Time::HiRes has been upgraded from version 1.9733 to 1.9741.

           [GH          #15396]         <https://github.com/Perl/perl5/issues/15396>         [GH         #15401]
           <https://github.com/Perl/perl5/issues/15401> [GH #15524] <https://github.com/Perl/perl5/issues/15524>
           [cpan #120032] <https://rt.cpan.org/Public/Bug/Display.html?id=120032>

Configuration and Compilation

       •   When building with GCC 6 and link-time optimization (the -flto option to gcc), Configure was treating
           all probed symbols as present on the system, regardless of whether they  actually  exist.   This  has
           been fixed.  [GH #15322] <https://github.com/Perl/perl5/issues/15322>

       •   Configure  now  aborts  if  both  "-Duselongdouble"  and  "-Dusequadmath" are requested.  [GH #14944]
           <https://github.com/Perl/perl5/issues/14944>

       •   Fixed a bug in which Configure could append "-quadmath" to  the  archname  even  if  it  was  already
           present.  [GH #15423] <https://github.com/Perl/perl5/issues/15423>

       •   Clang  builds  with  "-DPERL_GLOBAL_STRUCT"  or  "-DPERL_GLOBAL_STRUCT_PRIVATE"  have  been fixed (by
           disabling Thread Safety Analysis for these configurations).

Platform Support

   Platform-Specific Notes
       VMS
           •   "configure.com" now recognizes the VSI-branded C compiler.

       Windows
           •   Building XS modules with GCC 6 in a 64-bit build of Perl  failed  due  to  incorrect  mapping  of
               "strtoll"     and     "strtoull".      This     has     now     been    fixed.     [GH    #16074]
               <https://github.com/Perl/perl5/issues/16074>                    [cpan                    #121683]
               <https://rt.cpan.org/Public/Bug/Display.html?id=121683>               [cpan              #122353]
               <https://rt.cpan.org/Public/Bug/Display.html?id=122353>

Selected Bug Fixes

       •   "/@0{0*->@*/*0" and similar contortions used to crash, but no longer do, but merely produce a  syntax
           error.  [GH #15333] <https://github.com/Perl/perl5/issues/15333>

       •   "do" or "require" with an argument which is a reference or typeglob which, when stringified, contains
           a   null   character,  started  crashing  in  Perl  5.20,  but  has  now  been  fixed.   [GH  #15337]
           <https://github.com/Perl/perl5/issues/15337>

       •   Expressions containing an "&&" or "||" operator  (or  their  synonyms  "and"  and  "or")  were  being
           compiled  incorrectly  in  some  cases.  If the left-hand side consisted of either a negated bareword
           constant or a negated "do {}" block  containing  a  constant  expression,  and  the  right-hand  side
           consisted  of  a  negated non-foldable expression, one of the negations was effectively ignored.  The
           same was true of "if" and "unless" statement modifiers, though  with  the  left-hand  and  right-hand
           sides    swapped.     This    long-standing    bug    has    now    been    fixed.     [GH    #15285]
           <https://github.com/Perl/perl5/issues/15285>

       •   "reset" with an argument no longer crashes when encountering stash entries  other  than  globs.   [GH
           #15314] <https://github.com/Perl/perl5/issues/15314>

       •   Assignment  of  hashes  to,  and  deletion of, typeglobs named *:::::: no longer causes crashes.  [GH
           #15307] <https://github.com/Perl/perl5/issues/15307>

       •   Assignment variants of any bitwise ops under the "bitwise" feature would crash if the left-hand  side
           was an array or hash.  [GH #15346] <https://github.com/Perl/perl5/issues/15346>

       •   "socket"  now  leaves  the  error  code  returned  by  the  system  in  $!  on  failure.  [GH #15383]
           <https://github.com/Perl/perl5/issues/15383>

       •   Parsing    bad     POSIX     charclasses     no     longer     leaks     memory.      [GH     #15382]
           <https://github.com/Perl/perl5/issues/15382>

       •   Since Perl 5.20, line numbers have been off by one when perl is invoked with the -x switch.  This has
           been fixed.  [GH #15413] <https://github.com/Perl/perl5/issues/15413>

       •   Some  obscure  cases  of  subroutines  and  file handles being freed at the same time could result in
           crashes,  but  have  been  fixed.   The  crash  was   introduced   in   Perl   5.22.    [GH   #15435]
           <https://github.com/Perl/perl5/issues/15435>

       •   Some  regular  expression  parsing glitches could lead to assertion failures with regular expressions
           such   as    "/(?<=/"    and    "/(?<!/".     This    has    now    been    fixed.     [GH    #15332]
           <https://github.com/Perl/perl5/issues/15332>

       •   "gethostent"  and  similar  functions now perform a null check internally, to avoid crashing with the
           torsocks    library.     This    was    a    regression    from    Perl    5.22.      [GH     #15478]
           <https://github.com/Perl/perl5/issues/15478>

       •   Mentioning  the  same  constant twice in a row (which is a syntax error) no longer fails an assertion
           under   debugging   builds.    This   was   a   regression   from    Perl    5.20.     [GH    #15017]
           <https://github.com/Perl/perl5/issues/15017>

       •   In Perl 5.24 "fchown" was changed not to accept negative one as an argument because in some platforms
           that  is an error.  However, in some other platforms that is an acceptable argument.  This change has
           been reverted.  [GH #15523] <https://github.com/Perl/perl5/issues/15523>.

       •   "@{x" followed by a newline where "x" represents a control or non-ASCII character no longer  produces
           a garbled syntax error message or a crash.  [GH #15518] <https://github.com/Perl/perl5/issues/15518>

       •   A  regression  in  Perl 5.24 with "tr/\N{U+...}/foo/" when the code point was between 128 and 255 has
           been fixed.  [GH #15475] <https://github.com/Perl/perl5/issues/15475>.

       •   Many issues relating to "printf "%a"" of hexadecimal floating point were  fixed.   In  addition,  the
           "subnormals"  (formerly  known as "denormals") floating point numbers are now supported both with the
           plain IEEE 754 floating point numbers (64-bit or 128-bit) and the x86  80-bit  "extended  precision".
           Note  that  subnormal  hexadecimal  floating  point  literals  will  give  a  warning about "exponent
           underflow".      [GH     #15495]     <https://github.com/Perl/perl5/issues/15495>     [GH     #15502]
           <https://github.com/Perl/perl5/issues/15502> [GH #15503] <https://github.com/Perl/perl5/issues/15503>
           [GH          #15504]         <https://github.com/Perl/perl5/issues/15504>         [GH         #15505]
           <https://github.com/Perl/perl5/issues/15505> [GH #15510] <https://github.com/Perl/perl5/issues/15510>
           [GH #15512] <https://github.com/Perl/perl5/issues/15512>

       •   The  parser  could  sometimes  crash  if  a   bareword   came   after   "evalbytes".    [GH   #15586]
           <https://github.com/Perl/perl5/issues/15586>

       •   Fixed  a  place  where the regex parser was not setting the syntax error correctly on a syntactically
           incorrect pattern.  [GH #15565] <https://github.com/Perl/perl5/issues/15565>

       •   A vulnerability in Perl's "sprintf" implementation has been fixed by avoiding a possible memory wrap.
           [GH #15970] <https://github.com/Perl/perl5/issues/15970>

Acknowledgements

Perl 5.24.3 represents approximately 2 months of development since Perl 5.24.2 and contains approximately
3,200 lines of changes across 120 files from 23 authors.

Excluding auto-generated files, documentation and release tools, there were approximately 1,600 lines of
changes to 56 .pm, .t, .c and .h files.

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 5.24.3:

Aaron Crane, Craig A. Berry, Dagfinn Ilmari Mannsåker, Dan Collins, Daniel Dragan, Dave Cross, David
Mitchell, Eric Herman, Father Chrysostomos, H.Merijn Brand, Hugo van der Sanden, James E Keenan, Jarkko
Hietaniemi, John SJ Anderson, Karl Williamson, Ken Brown, Lukas Mai, Matthew Horsfall, Stevan Little,
Steve Hay, Steven Humphrey, 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 <https://rt.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.

       If  the bug you are reporting has security implications which make it inappropriate to send to a publicly
       archived mailing list, then see "SECURITY VULNERABILITY CONTACT INFORMATION" in perlsec  for  details  of
       how to report the issue.