=over 4
-=item * C<.> no longer in C<@INC>
+=item * C<"."> no longer in C<@INC>
-For security reasons, the current directory (C<.>) is no longer included
+For security reasons, the current directory (C<".">) is no longer included
by default at the end of the module search path (C<@INC>). This may have
widespread implications for the building, testing and installing of
modules, and for the execution of scripts. See the section
-L<< Removal of the current directory (C<.>) from C<@INC> >>
+L<< Removal of the current directory (C<".">) from C<@INC> >>
for the full details.
=item * C<do> may now warn
C<do> now gives a deprecation warning when it fails to load a file which
-it would have loaded had C<.> been in C<@INC>.
+it would have loaded had C<"."> been in C<@INC>.
=item * In regular expression patterns, a literal left brace C<"{">
should be escaped
=head2 Indented Here-documents
-This adds a new modifier '~' to here-docs that tells the parser
+This adds a new modifier C<"~"> to here-docs that tells the parser
that it should look for /^\s*$DELIM\n/ as the closing delimiter.
These syntaxes are all supported:
<<~ "EOF";
<<~ `EOF`;
-The '~' modifier will strip, from each line in the here-doc, the
+The C<"~"> modifier will strip, from each line in the here-doc, the
same whitespace that appears before the delimiter.
Newlines will be copied as-is, and lines that don't include the
=head2 New regular expression modifier C</xx>
-Specifying two C<x> characters to modify a regular expression pattern
+Specifying two C<"x"> characters to modify a regular expression pattern
does everything that a single one does, but additionally TAB and SPACE
characters within a bracketed character class are generally ignored and
can be added to improve readability, like
=head1 Security
-=head2 Removal of the current directory (C<.>) from C<@INC>
+=head2 Removal of the current directory (C<".">) from C<@INC>
The perl binary includes a default set of paths in C<@INC>. Historically
-it has also included the current directory (C<.>) as the final entry,
+it has also included the current directory (C<".">) as the final entry,
unless run with taint mode enabled (C<perl -T>). While convenient, this has
security implications: for example, where a script attempts to load an
optional module when its current directory is untrusted (such as F</tmp>),
it could load and execute code from under that directory.
-Starting with v5.26, C<.> is always removed by default, not just under
+Starting with v5.26, C<"."> is always removed by default, not just under
tainting. This has major implications for installing modules and executing
scripts.
=item * C<Configure -Udefault_inc_excludes_dot>
There is a new C<Configure> option, C<default_inc_excludes_dot> (enabled
-by default) which builds a perl executable without C<.>; unsetting this
+by default) which builds a perl executable without C<".">; unsetting this
option using C<-U> reverts perl to the old behaviour. This may fix your
path issues but will reintroduce all the security concerns, so don't
build a perl executable like this unless you're I<really> confident that
=item * C<PERL_USE_UNSAFE_INC>
There is a new environment variable recognised by the perl interpreter.
-If this variable has the value C<1> when the perl interpreter starts up,
-then C<.> will be automatically appended to C<@INC> (except under tainting).
+If this variable has the value 1 when the perl interpreter starts up,
+then C<"."> will be automatically appended to C<@INC> (except under tainting).
This allows you restore the old perl interpreter behaviour on a
case-by-case basis. But note that this is intended to be a temporary crutch,
While it is well-known that C<use> and C<require> use C<@INC> to search
for the file to load, many people don't realise that C<do "file"> also
-searches C<@INC> if the file is a relative path. With the removal of C<.>,
+searches C<@INC> if the file is a relative path. With the removal of C<".">,
a simple C<do "file.pl"> will fail to read in and execute C<file.pl> from
the current directory. Since this is commonly expected behaviour, a new
mandatory warning is now issued whenever C<do> fails to load a file which
If the issue is within your own code (rather than within included
modules), then you have two main options. Firstly, if you are confident
that your script will only be run within a trusted directory (under which
-you expect to find trusted files and modules), then add C<.> back into the
+you expect to find trusted files and modules), then add C<"."> back into the
path; I<e.g.>:
BEGIN {
If you maintain a CPAN distribution, it may need updating to run in
a dotless environment. Although C<cpan> and other such tools will
currently set the C<PERL_USE_UNSAFE_INC> during module build, this is a
-temporary workaround for the set of modules which rely on C<.> being in
+temporary workaround for the set of modules which rely on C<"."> being in
C<@INC> for installation and testing, and this may mask deeper issues. It
could result in a module which passes tests and installs, but which
fails at run time.
variable as tainted when starting a new process. Previously, it was
allowing a backslash to escape a colon (unlike the OS), consequently
allowing relative paths to be considered safe if the PATH was set to
-something like C</\:.>. The check has been fixed to treat C<.> as tainted
+something like C</\:.>. The check has been fixed to treat C<"."> as tainted
in that example.
=head2 C<-Di> switch is now required for PerlIO debugging output
in actual code, as they would typically display as attached to the
character in front of them.
-=head1 Removed Deprecations
+=head2 C<\cI<X>> that maps to a printable is no longer deprecated
-The C<\cI<X>> construct is intended to be a way to specify non-printable
-characters. Previously it was deprecated to use it for a printable one,
-which is better written as simply itself, perhaps preceded by a
-backslash for non-word characters. Now this raises a warning, but not a
-deprecation. See
+This means we have no plans to remove this feature. It still raises a
+warning, but only if syntax warnings are enabled. The feature was
+originally intended to be a way to express non-printable characters that
+don't have a mnemonic (C<\t> and C<\n> are mnemonics for two
+non-printable characters, but most non-printables don't have a
+mnemonic.) But the feature can be used to specify a few printable
+characters, though those are more clearly expressed as the printable
+itself. See
L<http://www.nntp.perl.org/group/perl.perl5.porters/2017/02/msg242944.html>.
=head1 Performance Enhancements
in the LHS of a list assignment, such as C<(..., @a) = (...);>, it's
likely to be considerably faster, especially if it involves emptying the
array/hash. For example this code runs about 1/3 faster compared to
-5.24.0:
+Perl 5.24.0:
my @a;
for my $i (1..10_000_000) {
regular expression pattern modifier, and a change to the L<S<C<use re
'strict'>>|re/'strict' mode> experimental feature. When S<C<re
'strict'>> is enabled, a warning now will be generated for all
-unescaped uses of the two characters C<}> and C<]> in regular
+unescaped uses of the two characters C<"}"> and C<"]"> in regular
expression patterns (outside bracketed character classes) that are taken
-literally. This brings them more in line with the C<)> character which
+literally. This brings them more in line with the C<")"> character which
is always a metacharacter unless escaped. Being a metacharacter only
sometimes, depending on action at a distance, can lead to silently
having the pattern mean something quite different than was intended,
We have attempted to update the documentation to reflect the changes
listed in this document. If you find any we have missed, send email to
-L<mailto:perlbug@perl.org>.
+L<perlbug@perl.org|mailto:perlbug@perl.org>.
Additionally all references to Usenet have been removed, and the
following selected changes have been made:
=item *
In L<C<split()>|perlfunc/split> added a caution about its use in Perls
-before 5.11, and noted that certain pattern modifiers are legal in it.
+before v5.11, and noted that certain pattern modifiers are legal in it.
=item *
=over 4
+=item *
+
Some locales aren't compatible with Perl. Note that these can cause
core dumps.
=item *
-Since C<.> is now removed from C<@INC> by default, C<do> will now trigger
+Since C<"."> is now removed from C<@INC> by default, C<do> will now trigger
a warning recommending to fix the C<do> statement:
L<do "%s" failed, '.' is no longer in @INC|perldiag/do "%s" failed, '.' is no longer in @INC; did you mean do ".E<sol>%s"?>
=item *
-L<Unescaped left brace in regex is illegal here|perldiag/Unescaped left brace in regex is illegal here in regex; marked by S<E<lt>-- HERE> in m/%s/>
+L<Unescaped left brace in regex is illegal here|perldiag/Unescaped left brace in regex is illegal here in regex; marked by S<E<lt>-- HERE> in mE<sol>%sE<sol>>
Unescaped left braces are now illegal in some contexts in regular expression
patterns. In other contexts, they are still just deprecated; they will
=item *
-Since C<.> is now removed from C<@INC> by default, C<do> will now trigger
+Since C<"."> is now removed from C<@INC> by default, C<do> will now trigger
a warning recommending to fix the C<do> statement:
L<do "%s" failed, '.' is no longer in @INC|perldiag/do "%s" failed, '.' is no longer in @INC; did you mean do ".E<sol>%s"?>
=item *
-Since 5.18 for testing purposes we have included support for
+Since v5.18 for testing purposes we have included support for
building perl with a variety of non-standard, and non-recommended
hash functions. Since we do not recommend the use of these functions
we have removed them and their corresponding build options. Specifically
=head1 Testing
+Tests were added and changed to reflect the other additions and changes
+in this release. In addition, these substantive changes were made:
+
=over 4
=item *
-F<XS-APItest/t/utf8.t>: Several small fixes and enhancements.
+A new test script, F<comp/parser_run.t>, has been added to test
+reads through invalid pointers.
=item *
=item *
+A new test script, F<t/re/keep_tabs.t> has been added to contain tests
+where C<\t> characters should not be expanded into spaces.
+
+=item *
+
A new test script, F<t/re/anyof.t>, has been added to test that the ANYOF nodes
generated by bracketed character classes are as expected.
=item *
+There is now more extensive testing of the Unicode-related API macros
+and functions.
+
+=item *
+
+Several of the longer running API test files have been split into
+multiple test files so that they can be run in parallel.
+
+=item *
+
F<t/harness> now tries really hard not to run tests outside of the Perl
source tree. [perl #124050]
=item *
The path separator for the C<PERL5LIB> and C<PERLLIB> environment entries is
-now a colon (C<:>) when running under a Unix shell. There is no change when
-running under DCL (it's still C<|>).
+now a colon (C<":">) when running under a Unix shell. There is no change when
+running under DCL (it's still C<"|">).
=item *
=item *
-The C<op_class()> API function has been added. This is like the existing
-C<OP_CLASS()> macro, but can more accurately determine what struct an op
-has been allocated as. For example C<OP_CLASS()> might return
-C<OA_BASEOP_OR_UNOP> indicating that ops of this type are usually
-allocated as an C<OP> or C<UNOP>; while C<op_class()> will return
-C<OPclass_BASEOP> or C<OPclass_UNOP> as appropriate.
+A new API function C<sv_setvpv_bufsize()> allows simultaneously setting the
+length and allocated size of the buffer in an C<SV>, growing the buffer if
+necessary.
=item *
-The output format of the C<op_dump()> function (as used by C<perl -Dx>)
-has changed: it now displays an "ASCII-art" tree structure, and shows more
-low-level details about each op, such as its address and class.
+A new API macro C<SvPVCLEAR()> sets its C<SV> argument to an empty string,
+like Perl-space C<$x = ''>, but with several optimisations.
+
+=item *
+
+Several new macros and functions for dealing with Unicode and
+UTF-8-encoded strings have been added to the API, as well some changes in
+functionality of existing functions (see L<perlapi/Unicode Support> for
+more details):
+
+=over
=item *
=item *
-Calling the functions C<utf8n_to_uvchr> and its derivatives, while
-passing a string length of 0 is now asserted against in DEBUGGING
-builds, and otherwise returns the Unicode REPLACEMENT CHARACTER. If
-you have nothing to decode, you shouldn't call the decode function.
+Several new macros for analysing the validity of utf8 sequences. These
+are:
+
+L<C<UTF8_GOT_ABOVE_31_BIT>|perlapi/UTF8_GOT_ABOVE_31_BIT>
+L<C<UTF8_GOT_CONTINUATION>|perlapi/UTF8_GOT_CONTINUATION>
+L<C<UTF8_GOT_EMPTY>|perlapi/UTF8_GOT_EMPTY>
+L<C<UTF8_GOT_LONG>|perlapi/UTF8_GOT_LONG>
+L<C<UTF8_GOT_NONCHAR>|perlapi/UTF8_GOT_NONCHAR>
+L<C<UTF8_GOT_NON_CONTINUATION>|perlapi/UTF8_GOT_NON_CONTINUATION>
+L<C<UTF8_GOT_OVERFLOW>|perlapi/UTF8_GOT_OVERFLOW>
+L<C<UTF8_GOT_SHORT>|perlapi/UTF8_GOT_SHORT>
+L<C<UTF8_GOT_SUPER>|perlapi/UTF8_GOT_SUPER>
+L<C<UTF8_GOT_SURROGATE>|perlapi/UTF8_GOT_SURROGATE>
+L<C<UTF8_IS_INVARIANT>|perlapi/UTF8_IS_INVARIANT>
+L<C<UTF8_IS_NONCHAR>|perlapi/UTF8_IS_NONCHAR>
+L<C<UTF8_IS_SUPER>|perlapi/UTF8_IS_SUPER>
+L<C<UTF8_IS_SURROGATE>|perlapi/UTF8_IS_SURROGATE>
+L<C<UVCHR_IS_INVARIANT>|perlapi/UVCHR_IS_INVARIANT>
+L<C<isUTF8_CHAR_flags>|perlapi/isUTF8_CHAR_flags>
+L<C<isSTRICT_UTF8_CHAR>|perlapi/isSTRICT_UTF8_CHAR>
+L<C<isC9_STRICT_UTF8_CHAR>|perlapi/isC9_STRICT_UTF8_CHAR>
=item *
-The functions C<utf8n_to_uvchr> and its derivatives now return the
-Unicode REPLACEMENT CHARACTER if called with UTF-8 that has the overlong
-malformation, and that malformation is allowed by the input parameters.
-This malformation is where the UTF-8 looks valid syntactically, but
-there is a shorter sequence that yields the same code point. This has
-been forbidden since Unicode version 3.1.
+Functions that are all extensions of the C<is_utf8_string_*()> functions,
+that apply various restrictions to the UTF-8 recognized as valid:
+
+L<C<is_strict_utf8_string>|perlapi/is_strict_utf8_string>,
+L<C<is_strict_utf8_string_loc>|perlapi/is_strict_utf8_string_loc>,
+L<C<is_strict_utf8_string_loclen>|perlapi/is_strict_utf8_string_loclen>,
+
+L<C<is_c9strict_utf8_string>|perlapi/is_c9strict_utf8_string>,
+L<C<is_c9strict_utf8_string_loc>|perlapi/is_c9strict_utf8_string_loc>,
+L<C<is_c9strict_utf8_string_loclen>|perlapi/is_c9strict_utf8_string_loclen>,
+
+L<C<is_utf8_string_flags>|perlapi/is_utf8_string_flags>,
+L<C<is_utf8_string_loc_flags>|perlapi/is_utf8_string_loc_flags>,
+L<C<is_utf8_string_loclen_flags>|perlapi/is_utf8_string_loclen_flags>,
+
+L<C<is_utf8_fixed_width_buf_flags>|perlapi/is_utf8_fixed_width_buf_flags>,
+L<C<is_utf8_fixed_width_buf_loc_flags>|perlapi/is_utf8_fixed_width_buf_loc_flags>,
+L<C<is_utf8_fixed_width_buf_loclen_flags>|perlapi/is_utf8_fixed_width_buf_loclen_flags>.
+
+L<C<is_utf8_invariant_string>|perlapi/is_utf8_invariant_string>.
+L<C<is_utf8_valid_partial_char>|perlapi/is_utf8_valid_partial_char>.
+L<C<is_utf8_valid_partial_char_flags>|perlapi/is_utf8_valid_partial_char_flags>.
=item *
-The functions C<utf8n_to_uvchr> and its derivatives now accept an input
+The functions L<C<utf8n_to_uvchr>|perlapi/utf8n_to_uvchr> and its
+derivatives have had several changes of behaviour.
+
+Calling them, while passing a string length of 0 is now asserted against
+in DEBUGGING builds, and otherwise returns the Unicode REPLACEMENT
+CHARACTER. If you have nothing to decode, you shouldn't call the decode
+function.
+
+They now return the Unicode REPLACEMENT CHARACTER if called with UTF-8
+that has the overlong malformation, and that malformation is allowed by
+the input parameters. This malformation is where the UTF-8 looks valid
+syntactically, but there is a shorter sequence that yields the same code
+point. This has been forbidden since Unicode version 3.1.
+
+They now accept an input
flag to allow the overflow malformation. This malformation is when the
UTF-8 may be syntactically valid, but the code point it represents is
not capable of being represented in the word length on the platform.
but it returns the Unicode REPLACEMENT CHARACTER as the value of the
code point (since the real value is not representable).
-=item *
-
-There is now a safer version of utf8_hop(), called utf8_hop_safe().
-Unlike utf8_hop(), utf8_hop_safe() won't navigate before the beginning or
-after the end of the supplied buffer.
-
-=item *
-
-The C<PADOFFSET> type has changed from being unsigned to signed, and
-several pad-related variables such as C<PL_padix> have changed from being
-of type C<I32> to type C<PADOFFSET>.
-
-=item *
-
-The function C<L<perlapi/utf8n_to_uvchr>> has been changed to not
+C<utf8n_to_uvchr> has been changed to not
abandon searching for other malformations when the first one is
encountered. A call to it thus can generate multiple diagnostics,
instead of just one.
=item *
-A new function, C<L<perlapi/utf8n_to_uvchr_error>>, has been added for
+C<valid_utf8_to_uvchr()> has been added to the API (although it was
+present in core earlier). Like C<utf8_to_uvchr_buf()>, but assumes that
+the next character is well-formed.
+
+=item *
+
+A new function, L<C<utf8n_to_uvchr_error>|perlapi/utf8n_to_uvchr_error>,
+has been added for
use by modules that need to know the details of UTF-8 malformations
beyond pass/fail. Previously, the only ways to know why a sequence was
ill-formed was to capture and parse the generated diagnostics, or to do
=item *
-Several new functions for handling Unicode have been added to the API:
-C<L<perlapi/is_strict_utf8_string>>,
-C<L<perlapi/is_c9strict_utf8_string>>,
-C<L<perlapi/is_utf8_string_flags>>,
-C<L<perlapi/is_strict_utf8_string_loc>>,
-C<L<perlapi/is_strict_utf8_string_loclen>>,
-C<L<perlapi/is_c9strict_utf8_string_loc>>,
-C<L<perlapi/is_c9strict_utf8_string_loclen>>,
-C<L<perlapi/is_utf8_string_loc_flags>>,
-C<L<perlapi/is_utf8_string_loclen_flags>>,
-C<L<perlapi/is_utf8_fixed_width_buf_flags>>,
-C<L<perlapi/is_utf8_fixed_width_buf_loc_flags>>,
-C<L<perlapi/is_utf8_fixed_width_buf_loclen_flags>>.
-
-These functions are all extensions of the C<is_utf8_string_*()> functions,
-that apply various restrictions to the UTF-8 recognized as valid.
+There is now a safer version of utf8_hop(), called utf8_hop_safe().
+Unlike utf8_hop(), utf8_hop_safe() won't navigate before the beginning or
+after the end of the supplied buffer.
=item *
-A new API function C<sv_setvpv_bufsize()> allows simultaneously setting the
-length and allocated size of the buffer in an C<SV>, growing the buffer if
-necessary.
+Two new functions, C<utf8_hop_forward()> and C<utf8_hop_back()> are
+similar to C<utf8_hop_safe()> but are for when you know which direction
+you wish to travel.
=item *
-A new API macro C<SvPVCLEAR()> sets its C<SV> argument to an empty string,
-like Perl-space C<$x = ''>, but with several optimisations.
+Two new macros which return useful utf8 byte sequences:
-=item *
+L<C<BOM_UTF8>|perlapi/BOM_UTF8>
+L<C<REPLACEMENT_CHARACTER_UTF8>|perlapi/REPLACEMENT_CHARACTER_UTF8>
-All parts of the internals now agree that the C<sassign> op is a C<BINOP>;
-previously it was listed as a C<BASEOP> in F<regen/opcodes>, which meant
-that several parts of the internals had to be special-cased to accommodate
-it. This oddity's original motivation was to handle code like C<$x ||= 1>;
-that is now handled in a simpler way.
+=back
=item *
-Several new internal C macros have been added that take a string literal as
-arguments, alongside existing routines that take the equivalent value as two
-arguments, a character pointer and a length. The advantage of this is that
-the length of the string is calculated automatically, rather than having to
-be done manually. These routines are now used where appropriate across the
-entire codebase.
-
-=item *
+Perl is now built with the C<PERL_OP_PARENT> compiler define enabled by
+default. To disable it, use the C<PERL_NO_OP_PARENT> compiler define.
+This flag alters how the C<op_sibling> field is used in C<OP> structures,
+and has been available optionally since perl 5.22.
-The code in F<gv.c> that determines whether a variable has a special meaning
-to Perl has been simplified.
+See L<perl5220delta/"Internal Changes"> for more details of what this
+build option does.
=item *
-The C<DEBUGGING>-mode output for regex compilation and execution has been
-enhanced.
+Three new ops, C<OP_ARGELEM>, C<OP_ARGDEFELEM> and C<OP_ARGCHECK> have
+been added. These are intended principally to implement the individual
+elements of a subroutine signature, plus any overall checking required.
=item *
-Several macros and functions have been added to the public API for
-dealing with Unicode and UTF-8-encoded strings. See
-L<perlapi/Unicode Support>.
+The C<op_class()> API function has been added. This is like the existing
+C<OP_CLASS()> macro, but can more accurately determine what struct an op
+has been allocated as. For example C<OP_CLASS()> might return
+C<OA_BASEOP_OR_UNOP> indicating that ops of this type are usually
+allocated as an C<OP> or C<UNOP>; while C<op_class()> will return
+C<OPclass_BASEOP> or C<OPclass_UNOP> as appropriate.
=item *
-Use C<my_strlcat()> in C<locale.c>. While C<strcat()> is safe in this context,
-some compilers were optimizing this to C<strcpy()> causing a porting test to
-fail that looks for unsafe code. Rather than fighting this, we just use
-C<my_strlcat()> instead.
+All parts of the internals now agree that the C<sassign> op is a C<BINOP>;
+previously it was listed as a C<BASEOP> in F<regen/opcodes>, which meant
+that several parts of the internals had to be special-cased to accommodate
+it. This oddity's original motivation was to handle code like C<$x ||= 1>;
+that is now handled in a simpler way.
=item *
-Three new ops, C<OP_ARGELEM>, C<OP_ARGDEFELEM> and C<OP_ARGCHECK> have
-been added. These are intended principally to implement the individual
-elements of a subroutine signature, plus any overall checking required.
+The output format of the C<op_dump()> function (as used by C<perl -Dx>)
+has changed: it now displays an "ASCII-art" tree structure, and shows more
+low-level details about each op, such as its address and class.
=item *
-Perl no longer panics when switching into some locales on machines with
-buggy C<strxfrm()> implementations in their libc. [perl #121734]
+The C<PADOFFSET> type has changed from being unsigned to signed, and
+several pad-related variables such as C<PL_padix> have changed from being
+of type C<I32> to type C<PADOFFSET>.
=item *
-Perl is now built with the C<PERL_OP_PARENT> compiler define enabled by
-default. To disable it, use the C<PERL_NO_OP_PARENT> compiler define.
-This flag alters how the C<op_sibling> field is used in C<OP> structures,
-and has been available optionally since perl 5.22.
-
-See L<perl5220delta/"Internal Changes"> for more details of what this
-build option does.
+The C<DEBUGGING>-mode output for regex compilation and execution has been
+enhanced.
=item *
-The meanings of some internal SV flags have been changed
-
-OPpRUNTIME, SVpbm_VALID, SVpbm_TAIL, SvTAIL_on, SvTAIL_off, SVrepl_EVAL,
-SvEVALED
+Several obscure SV flags have been eliminated, sometimes along with the
+macros which manipulate them: C<SVpbm_VALID>, C<SVpbm_TAIL>, C<SvTAIL_on>,
+C<SvTAIL_off>, C<SVrepl_EVAL>, C<SvEVALED>
=item *
-Change C<hv_fetch(…, "…", …, …)> to C<hv_fetchs(…, "…", …)>
-
-The dual-life dists all use Devel::PPPort, so they can use this function even
-though it was only added in 5.10.
+An OP op_private flag has been eliminated: C<OPpRUNTIME>. This used to
+often get set on C<PMOP>s, but had become meaningless over time.
=back
=item *
+Perl no longer panics when switching into some locales on machines with
+buggy C<strxfrm()> implementations in their libc. [perl #121734]
+
+=item *
+
C< $-{$name} > would leak an C<AV> on each access if the regular
expression had no named captures. The same applies to access to any
hash tied with L<Tie::Hash::NamedCapture> and C<< all =E<gt> 1 >>. [perl
=item *
-Since 5.24 in some obscure cases, a regex which included code blocks
+Since v5.24 in some obscure cases, a regex which included code blocks
from multiple sources (I<e.g.>, via embedded via qr// objects) could end up
with the wrong current pad and crash or give weird results. [perl #129881]
=item *
-The range operator C<..> on strings now handles its arguments correctly when in
+The range operator C<".."> on strings now handles its arguments correctly when in
the scope of the L<< C<unicode_strings>|feature/"The 'unicode_strings' feature" >>
feature. The previous behaviour was sufficiently unexpected that we believe no
correct program could have made use of it.
=item *
-Using a large code point with the C<W> pack template character with
+Using a large code point with the C<"W"> pack template character with
the current output position aligned at just the right point could
cause a write a single zero byte immediately beyond the end of an
allocated buffer. [perl #129149]
=item *
-Only warn once per literal about a misplaced C<_>. [perl #70878].
+Only warn once per literal about a misplaced C<"_">. [perl #70878].
=item *
=item *
-The C<&.> operator (and the C<&> operator, when it treats its arguments as
+The C<&.> operator (and the C<"&"> operator, when it treats its arguments as
strings) were failing to append a trailing null byte if at least one string
was marked as utf8 internally. Many code paths (system calls, regexp
compilation) still expect there to be a null byte in the string buffer
=item *
Fixed the parser error handling for an 'C<:attr(foo>' that does not have
-an ending 'C<)>'.
+an ending 'C<")">'.
=item *
=item *
C<gethostent> and similar functions now perform a null check internally, to
-avoid crashing with torsocks. This was a regression from 5.22. [perl
+avoid crashing with torsocks. This was a regression from v5.22. [perl
#128740]
=item *
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 5.20. [perl #126482]
+from v5.20. [perl #126482]
=item *
=item *
-A regression in 5.24 with C<tr/\N{U+...}/foo/> when the code point was between
+A regression in v5.24 with C<tr/\N{U+...}/foo/> when the code point was between
128 and 255 has been fixed. [perl #128734].
=item *
Use of a string delimiter whose code point is above 2**31 now works
correctly on platforms that allow this. Previously, certain characters,
due to truncation, would be confused with other delimiter characters
-with special meaning (such as C<?> in C<m?...?>), resulting
+with special meaning (such as C<"?"> in C<m?...?>), resulting
in inconsistent behaviour. Note that this is non-portable,
and is based on Perl's extension to UTF-8, and is probably not
displayable nor enterable by any editor. [perl #128738]
=item *
-C<@{x> followed by a newline where C<x> represents a control or non-ASCII
+C<@{x> followed by a newline where C<"x"> represents a control or non-ASCII
character no longer produces a garbled syntax error message or a crash.
[perl #128951]
=item * L<Coro>
-L<Coro> and perl 5.22 were already incompatible due to a change in the perl,
+L<Coro> and Perl 5.22 were already incompatible due to a change in the perl,
and the reworking on the perl context stack creates a further incompatibility.
perl5-porters has L<discussed the issue on the mailing
list|http://www.nntp.perl.org/group/perl.perl5.porters/2016/05/msg236174.html>.