upstream/postgresql
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2026-02-20 08:20:55 -05:00
Code Issues Projects Releases Packages Wiki Activity Actions
Base de données relationnelle
63315 commits 38 branches 674 tags 843 MiB
C 84.8%
PLpgSQL 6.1%
Perl 4.7%
Yacc 1.2%
Meson 0.7%
Other 2.4%
Find a file
Noah Misch 9f4fd119b2 Fix SUBSTRING() for toasted multibyte characters. 
Commit 1e7fe06c10 changed
pg_mbstrlen_with_len() to ereport(ERROR) if the input ends in an
incomplete character.  Most callers want that.  text_substring() does
not.  It detoasts the most bytes it could possibly need to get the
requested number of characters.  For example, to extract up to 2 chars
from UTF8, it needs to detoast 8 bytes.  In a string of 3-byte UTF8
chars, 8 bytes spans 2 complete chars and 1 partial char.

Fix this by replacing this pg_mbstrlen_with_len() call with a string
traversal that differs by stopping upon finding as many chars as the
substring could need.  This also makes SUBSTRING() stop raising an
encoding error if the incomplete char is past the end of the substring.
This is consistent with the general philosophy of the above commit,
which was to raise errors on a just-in-time basis.  Before the above
commit, SUBSTRING() never raised an encoding error.

SUBSTRING() has long been detoasting enough for one more char than
needed, because it did not distinguish exclusive and inclusive end
position.  For avoidance of doubt, stop detoasting extra.

Back-patch to v14, like the above commit.  For applications using
SUBSTRING() on non-ASCII column values, consider applying this to your
copy of any of the February 12, 2026 releases.

Reported-by: SATŌ Kentarō <ranvis@gmail.com>
Reviewed-by: Thomas Munro <thomas.munro@gmail.com>
Bug: #19406
Discussion: https://postgr.es/m/19406-9867fddddd724fca@postgresql.org
Backpatch-through: 14
2026-02-14 12:16:16 -08:00
.github Add CODE_OF_CONDUCT.md, CONTRIBUTING.md, and SECURITY.md. 2024-07-02 13:03:58 -05:00
config Revert "Change copyObject() to use typeof_unqual" 2026-02-07 10:08:38 +01:00
contrib Add support for INSERT ... ON CONFLICT DO SELECT. 2026-02-12 09:57:04 +00:00
doc doc: Mention PASSING support for jsonpath variables 2026-02-13 12:12:11 +01:00
src Fix SUBSTRING() for toasted multibyte characters. 2026-02-14 12:16:16 -08:00
.cirrus.star ci: Simplify ci-os-only handling 2025-08-14 12:09:34 -04:00
.cirrus.tasks.yml ci: Configure g++ with 32-bit for 32-bit build 2026-01-09 08:58:50 +01:00
.cirrus.yml ci: Per-repo configuration for manually trigger tasks 2025-08-14 11:54:03 -04:00
.dir-locals.el Make Emacs perl-mode indent more like perltidy. 2019-01-13 11:32:31 -08:00
.editorconfig Update .editorconfig and .gitattributes for postgresql.conf.sample. 2025-11-18 10:28:36 -06:00
.git-blame-ignore-revs Add a couple of recent commits to .git-blame-ignore-revs. 2026-01-28 15:56:48 -06:00
.gitattributes Update .editorconfig and .gitattributes for postgresql.conf.sample. 2025-11-18 10:28:36 -06:00
.gitignore Update top-level .gitignore. 2022-12-04 15:23:00 -05:00
.mailmap Add a Git .mailmap file 2024-11-05 13:56:02 +01:00
aclocal.m4 autoconf: Move export_dynamic determination to configure 2022-12-06 18:55:28 -08:00
configure Revert "Change copyObject() to use typeof_unqual" 2026-02-07 10:08:38 +01:00
configure.ac Revert "Change copyObject() to use typeof_unqual" 2026-02-07 10:08:38 +01:00
COPYRIGHT Update copyright for 2026 2026-01-01 13:24:10 -05:00
GNUmakefile.in Allow selecting the git revision to be packaged by "make dist". 2024-05-03 11:08:50 -04:00
HISTORY Canonicalize some URLs 2020-02-10 20:47:50 +01:00
Makefile Remove AIX support 2024-02-28 15:17:23 +04:00
meson.build meson: Add target for generating docs images 2026-02-13 11:50:14 +01:00
meson_options.txt Update copyright for 2026 2026-01-01 13:24:10 -05:00
README.md Revise the style of a paragraph in README.md. 2024-03-21 10:16:41 -05:00

README.md

PostgreSQL Database Management System

This directory contains the source code distribution of the PostgreSQL database management system.

PostgreSQL is an advanced object-relational database management system that supports an extended subset of the SQL standard, including transactions, foreign keys, subqueries, triggers, user-defined types and functions. This distribution also contains C language bindings.

Copyright and license information can be found in the file COPYRIGHT.

General documentation about this version of PostgreSQL can be found at https://www.postgresql.org/docs/devel/. In particular, information about building PostgreSQL from the source code can be found at https://www.postgresql.org/docs/devel/installation.html.

The latest version of this software, and related software, may be obtained at https://www.postgresql.org/download/. For more information look at our web site located at https://www.postgresql.org/.