{ "mode": "man", "parameter": "perl5203delta", "section": "1", "url": "https://www.chedong.com/phpMan.php/man/perl5203delta/1/json", "generated": "2026-07-05T13:33:22Z", "sections": { "NAME": { "content": "perl5203delta - what is new for perl v5.20.3\n", "subsections": [] }, "DESCRIPTION": { "content": "This document describes differences between the 5.20.2 release and the 5.20.3 release.\n\nIf you are upgrading from an earlier release such as 5.20.1, first read perl5202delta, which\ndescribes differences between 5.20.1 and 5.20.2.\n", "subsections": [ { "name": "Incompatible Changes", "content": "There are no changes intentionally incompatible with 5.20.2. If any exist, they are bugs,\nand we request that you submit a report. See \"Reporting Bugs\" below.\n" }, { "name": "Modules and Pragmata", "content": "" }, { "name": "Updated Modules and Pragmata", "content": "• Errno has been upgraded from version 1.2005 to 1.2006.\n\nAdd -P to the pre-processor command-line on GCC 5. GCC added extra line directives,\nbreaking parsing of error code definitions. [GH #14491]\n\n\n• Module::CoreList has been upgraded from version 5.20150214 to 5.20150822.\n\nUpdated to cover the latest releases of Perl.\n\n• perl5db.pl has been upgraded from 1.44 to 1.4401.\n\nThe debugger would cause an assertion failure. [GH #14605]\n\n" } ] }, "Documentation": { "content": "", "subsections": [ { "name": "Changes to Existing Documentation", "content": "perlfunc\n\n• Mention that \"study()\" is currently a no-op.\n\nperlguts\n\n• The OOK example has been updated to account for COW changes and a change in the storage\nof the offset.\n\nperlhacktips\n\n• Documentation has been added illustrating the perils of assuming the contents of static\nmemory pointed to by the return values of Perl wrappers for C library functions doesn't\nchange.\n\nperlpodspec\n\n• The specification of the POD language is changing so that the default encoding of PODs\nthat aren't in UTF-8 (unless otherwise indicated) is CP1252 instead of ISO-8859-1\n(Latin1).\n" }, { "name": "Utility Changes", "content": "" }, { "name": "h2ph", "content": "• h2ph now handles hexadecimal constants in the compiler's predefined macro definitions, as\nvisible in $Config{cppsymbols}. [GH #14491] \n" } ] }, "Testing": { "content": "• t/perf/taint.t has been added to see if optimisations with taint issues are keeping\nthings fast.\n\n• t/porting/recontext.t has been added to test that utf8 and its dependencies only use the\nsubset of the \"$1..$n\" capture vars that Perlsaverecontext() is hard-coded to\nlocalize, because that function has no efficient way of determining at runtime what vars\nto localize.\n", "subsections": [ { "name": "Platform Support", "content": "" }, { "name": "Platform-Specific Notes", "content": "Win32\n• Previously, when compiling with a 64-bit Visual C++, every Perl XS module (including\nCPAN ones) and Perl aware C file would unconditionally have around a dozen warnings\nfrom hvfunc.h. These warnings have been silenced. GCC (all bitness) and 32-bit\nVisual C++ were not affected.\n\n• miniperl.exe is now built with -fno-strict-aliasing, allowing 64-bit builds to\ncomplete with GCC 4.8. [GH #14556] \n" }, { "name": "Selected Bug Fixes", "content": "• Repeated global pattern matches in scalar context on large tainted strings were\nexponentially slow depending on the current match position in the string. [GH #14238]\n\n\n• The original visible value of $/ is now preserved when it is set to an invalid value.\nPreviously if you set $/ to a reference to an array, for example, perl would produce a\nruntime error and not set PLrs, but Perl code that checked $/ would see the array\nreference. [GH #14245] \n\n• Perl 5.14.0 introduced a bug whereby \"eval { LABEL: }\" would crash. This has been fixed.\n[GH #14438] \n\n• Extending an array cloned from a parent thread could result in \"Modification of a read-\nonly value attempted\" errors when attempting to modify the new elements. [GH #14605]\n\n\n• Several cases of data used to store environment variable contents in core C code being\npotentially overwritten before being used have been fixed. [GH #14476]\n\n\n• UTF-8 variable names used in array indexes, unquoted UTF-8 HERE-document terminators and\nUTF-8 function names all now work correctly. [GH #14601]\n\n\n• A subtle bug introduced in Perl 5.20.2 involving UTF-8 in regular expressions and\nsometimes causing a crash has been fixed. A new test script has been added to test this\nfix; see under \"Testing\". [GH #14600] \n\n• Some patterns starting with \"/.*..../\" matched against long strings have been slow since\nPerl 5.8, and some of the form \"/.*..../i\" have been slow since Perl 5.18. They are now\nall fast again. [GH #14475] \n\n• Warning fatality is now ignored when rewinding the stack. This prevents infinite\nrecursion when the now fatal error also causes rewinding of the stack. [GH #14319]\n\n\n• \"setpgrp($nonzero)\" (with one argument) was accidentally changed in Perl 5.16 to mean\nsetpgrp(0). This has been fixed.\n\n• A crash with \"%::=(); J->${\\\"::\"}\" has been fixed. [GH #14790]\n\n\n• Regular expression possessive quantifier Perl 5.20 regression now fixed.\n\"qr/\"PAT\"{\"min,max\"}+\"\"/\" is supposed to behave identically to\n\"qr/(?>\"PAT\"{\"min,max\"})/\". Since Perl 5.20, this didn't work if min and max were equal.\n[GH #14857] \n\n• Code like \"/$a[/\" used to read the next line of input and treat it as though it came\nimmediately after the opening bracket. Some invalid code consequently would parse and\nrun, but some code caused crashes, so this is now disallowed. [GH #14462]\n\n" } ] }, "Acknowledgements": { "content": "Perl 5.20.3 represents approximately 7 months of development since Perl 5.20.2 and contains\napproximately 3,200 lines of changes across 99 files from 26 authors.\n\nExcluding auto-generated files, documentation and release tools, there were approximately\n1,500 lines of changes to 43 .pm, .t, .c and .h files.\n\nPerl continues to flourish into its third decade thanks to a vibrant community of users and\ndevelopers. The following people are known to have contributed the improvements that became\nPerl 5.20.3:\n\nAlex Vandiver, Andy Dougherty, Aristotle Pagaltzis, Chris 'BinGOs' Williams, Craig A. Berry,\nDagfinn Ilmari Mannsåker, Daniel Dragan, David Mitchell, Father Chrysostomos, H.Merijn Brand,\nJames E Keenan, James McCoy, Jarkko Hietaniemi, Karen Etheridge, Karl Williamson, kmx, Lajos\nVeres, Lukas Mai, Matthew Horsfall, Petr Písař, Randy Stauner, Ricardo Signes, Sawyer X,\nSteve Hay, Tony Cook, Yves Orton.\n\nThe list above is almost certainly incomplete as it is automatically generated from version\ncontrol history. In particular, it does not include the names of the (very much appreciated)\ncontributors who reported issues to the Perl bug tracker.\n\nMany of the changes included in this version originated in the CPAN modules included in\nPerl's core. We're grateful to the entire CPAN community for helping Perl to flourish.\n\nFor a more complete list of all of Perl's historical contributors, please see the AUTHORS\nfile in the Perl source distribution.\n", "subsections": [ { "name": "Reporting Bugs", "content": "If you find what you think is a bug, you might check the articles recently posted to the\ncomp.lang.perl.misc newsgroup and the perl bug database at https://rt.perl.org/ . There may\nalso be information at http://www.perl.org/ , the Perl Home Page.\n\nIf you believe you have an unreported bug, please run the perlbug program included with your\nrelease. Be sure to trim your bug down to a tiny but sufficient test case. Your bug report,\nalong with the output of \"perl -V\", will be sent off to perlbug@perl.org to be analysed by\nthe Perl porting team.\n\nIf the bug you are reporting has security implications, which make it inappropriate to send\nto a publicly archived mailing list, then please send it to perl5-security-report@perl.org.\nThis points to a closed subscription unarchived mailing list, which includes all the core\ncommitters, who will be able to help assess the impact of issues, figure out a resolution,\nand help co-ordinate the release of patches to mitigate or fix the problem across all\nplatforms on which Perl is supported. Please only use this address for security issues in\nthe Perl core, not for modules independently distributed on CPAN.\n" } ] }, "SEE ALSO": { "content": "The Changes file for an explanation of how to view exhaustive details on what changed.\n\nThe INSTALL file for how to build Perl.\n\nThe README file for general stuff.\n\nThe Artistic and Copying files for copyright information.\n\n\n\nperl v5.34.0 2026-06-23 PERL5203DELTA(1)", "subsections": [] } }, "summary": "perl5203delta - what is new for perl v5.20.3", "flags": [], "examples": [], "see_also": [] }