5 perl5261delta - what is new for perl v5.26.1
9 This document describes differences between the 5.26.0 release and the 5.26.1
12 If you are upgrading from an earlier release such as 5.24.0, first read
13 L<perl5260delta>, which describes differences between 5.24.0 and 5.26.0.
17 =head2 [CVE-2017-12837] Heap buffer overflow in regular expression compiler
19 Compiling certain regular expression patterns with the case-insensitive
20 modifier could cause a heap buffer overflow and crash perl. This has now been
22 L<[perl #131582]|https://rt.perl.org/Public/Bug/Display.html?id=131582>
24 =head2 [CVE-2017-12883] Buffer over-read in regular expression parser
26 For certain types of syntax error in a regular expression pattern, the error
27 message could either contain the contents of a random, possibly large, chunk of
28 memory, or could crash perl. This has now been fixed.
29 L<[perl #131598]|https://rt.perl.org/Public/Bug/Display.html?id=131598>
31 =head2 [CVE-2017-12814] C<$ENV{$key}> stack buffer overflow on Windows
33 A possible stack buffer overflow in the C<%ENV> code on Windows has been fixed
34 by removing the buffer completely since it was superfluous anyway.
35 L<[perl #131665]|https://rt.perl.org/Public/Bug/Display.html?id=131665>
37 =head1 Incompatible Changes
39 There are no changes intentionally incompatible with 5.26.0. If any exist,
40 they are bugs, and we request that you submit a report. See L</Reporting
43 =head1 Modules and Pragmata
45 =head2 Updated Modules and Pragmata
51 L<base> has been upgraded from version 2.25 to 2.26.
53 The effects of dotless C<@INC> on this module have been limited by the
54 introduction of a more refined and accurate solution for removing C<'.'> from
55 C<@INC> while reducing the false positives.
59 L<charnames> has been upgraded from version 1.44 to 1.45.
63 L<Module::CoreList> has been upgraded from version 5.20170530 to 5.20170922_26.
67 =head1 Platform Support
69 =head2 Platform-Specific Notes
79 Building with B<g++> on FreeBSD-11.0 has been fixed.
80 L<[perl #131337]|https://rt.perl.org/Public/Bug/Display.html?id=131337>
90 Support for compiling perl on Windows using Microsoft Visual Studio 2017
91 (containing Visual C++ 14.1) has been added.
95 Building XS modules with GCC 6 in a 64-bit build of Perl failed due to
96 incorrect mapping of C<strtoll> and C<strtoull>. This has now been fixed.
97 L<[perl #131726]|https://rt.perl.org/Public/Bug/Display.html?id=131726>
98 L<[cpan #121683]|https://rt.cpan.org/Public/Bug/Display.html?id=121683>
99 L<[cpan #122353]|https://rt.cpan.org/Public/Bug/Display.html?id=122353>
105 =head1 Selected Bug Fixes
111 Several built-in functions previously had bugs that could cause them to write
112 to the internal stack without allocating room for the item being written. In
113 rare situations, this could have led to a crash. These bugs have now been
114 fixed, and if any similar bugs are introduced in future, they will be detected
115 automatically in debugging builds.
116 L<[perl #131732]|https://rt.perl.org/Public/Bug/Display.html?id=131732>
120 Using a symbolic ref with postderef syntax as the key in a hash lookup was
121 yielding an assertion failure on debugging builds.
122 L<[perl #131627]|https://rt.perl.org/Public/Bug/Display.html?id=131627>
126 List assignment (C<aassign>) could in some rare cases allocate an entry on the
127 mortal stack and leave the entry uninitialized.
128 L<[perl #131570]|https://rt.perl.org/Public/Bug/Display.html?id=131570>
132 Attempting to apply an attribute to an C<our> variable where a function of that
133 name already exists could result in a NULL pointer being supplied where an SV
134 was expected, crashing perl.
135 L<[perl #131597]|https://rt.perl.org/Public/Bug/Display.html?id=131597>
139 The code that vivifies a typeglob out of a code ref made some false assumptions
140 that could lead to a crash in cases such as C<< $::{"A"} = sub {}; \&{"A"} >>.
141 This has now been fixed.
142 L<[perl #131085]|https://rt.perl.org/Public/Bug/Display.html?id=131085>
146 C<my_atof2> no longer reads beyond the terminating NUL, which previously
147 occurred if the decimal point is immediately before the NUL.
148 L<[perl #131526]|https://rt.perl.org/Public/Bug/Display.html?id=131526>
152 Occasional "Malformed UTF-8 character" crashes in C<s//> on utf8 strings have
154 L<[perl #131575]|https://rt.perl.org/Public/Bug/Display.html?id=131575>
158 C<perldoc -f s> now finds C<s///>.
159 L<[perl #131371]|https://rt.perl.org/Public/Bug/Display.html?id=131371>
163 Some erroneous warnings after utf8 conversion have been fixed.
164 L<[perl #131190]|https://rt.perl.org/Public/Bug/Display.html?id=131190>
168 The C<jmpenv> frame to catch Perl exceptions is set up lazily, and this used to
169 be a bit too lazy. The catcher is now set up earlier, preventing some possible
171 L<[perl #105930]|https://rt.perl.org/Public/Bug/Display.html?id=105930>
175 Spurious "Assuming NOT a POSIX class" warnings have been removed.
176 L<[perl #131522]|https://rt.perl.org/Public/Bug/Display.html?id=131522>
180 =head1 Acknowledgements
182 Perl 5.26.1 represents approximately 4 months of development since Perl 5.26.0
183 and contains approximately 8,900 lines of changes across 85 files from 23
186 Excluding auto-generated files, documentation and release tools, there were
187 approximately 990 lines of changes to 38 .pm, .t, .c and .h files.
189 Perl continues to flourish into its third decade thanks to a vibrant community
190 of users and developers. The following people are known to have contributed
191 the improvements that became Perl 5.26.1:
193 Aaron Crane, Andy Dougherty, Aristotle Pagaltzis, Chris 'BinGOs' Williams,
194 Craig A. Berry, Dagfinn Ilmari Mannsåker, David Mitchell, E. Choroba, Eric
195 Herman, Father Chrysostomos, Jacques Germishuys, James E Keenan, John SJ
196 Anderson, Karl Williamson, Ken Brown, Lukas Mai, Matthew Horsfall, Ricardo
197 Signes, Sawyer X, Steve Hay, Tony Cook, Yves Orton, Zefram.
199 The list above is almost certainly incomplete as it is automatically generated
200 from version control history. In particular, it does not include the names of
201 the (very much appreciated) contributors who reported issues to the Perl bug
204 Many of the changes included in this version originated in the CPAN modules
205 included in Perl's core. We're grateful to the entire CPAN community for
206 helping Perl to flourish.
208 For a more complete list of all of Perl's historical contributors, please see
209 the F<AUTHORS> file in the Perl source distribution.
211 =head1 Reporting Bugs
213 If you find what you think is a bug, you might check the perl bug database
214 at L<https://rt.perl.org/> . There may also be information at
215 L<http://www.perl.org/> , the Perl Home Page.
217 If you believe you have an unreported bug, please run the L<perlbug> program
218 included with your release. Be sure to trim your bug down to a tiny but
219 sufficient test case. Your bug report, along with the output of C<perl -V>,
220 will be sent off to perlbug@perl.org to be analysed by the Perl porting team.
222 If the bug you are reporting has security implications which make it
223 inappropriate to send to a publicly archived mailing list, then see
224 L<perlsec/SECURITY VULNERABILITY CONTACT INFORMATION> for details of how to
229 If you wish to thank the Perl 5 Porters for the work we had done in Perl 5, you
230 can do so by running the C<perlthanks> program:
234 This will send an email to the Perl 5 Porters list with your show of thanks.
238 The F<Changes> file for an explanation of how to view exhaustive details on
241 The F<INSTALL> file for how to build Perl.
243 The F<README> file for general stuff.
245 The F<Artistic> and F<Copying> files for copyright information.