Mirror of the official PostgreSQL GIT repository. Note that this is just a *mirror* - we don't work with pull requests on github. To contribute, please see https://wiki.postgresql.org/wiki/Submitting_a_Patch
Go to file
Andres Freund ba1dfbe22d Fix edge case leading to agg transitions skipping ExecAggTransReparent() calls.
The code checking whether an aggregate transition value needs to be
reparented into the current context has always only compared the
transition return value with the previous transition value by datum,
i.e. without regard for NULLness.  This normally works, because when
the transition function returns NULL (via fcinfo->isnull), it'll
return a value that won't be the same as its input value.

But there's no hard requirement that that's the case. And it turns
out, it's possible to hit this case (see discussion or reproducers),
leading to a non-null transition value not being reparented, followed
by a crash caused by that.

Instead of adding another comparison of NULLness, instead have
ExecAggTransReparent() ensure that pergroup->transValue ends up as 0
when the new transition value is NULL. That avoids having to add an
additional branch to the much more common cases of the transition
function returning the old transition value (which is a pointer in
this case), and when the new value is different, but not NULL.

In branches since 69c3936a14, also deduplicate the reparenting code
between the expression evaluation based transitions, and the path for
ordered aggregates.

Reported-By: Teodor Sigaev, Nikita Glukhov
Author: Andres Freund
Discussion: https://postgr.es/m/bd34e930-cfec-ea9b-3827-a8bc50891393@sigaev.ru
Backpatch: 9.4-, this issue has existed since at least 7.4
2020-01-20 23:32:21 -08:00
config configure: Update python search order 2019-09-08 13:45:13 -04:00
contrib Disallow null category in crosstab_hash 2019-12-23 13:34:12 -05:00
doc doc: Fix naming of SELinux 2020-01-10 09:37:44 +09:00
src Fix edge case leading to agg transitions skipping ExecAggTransReparent() calls. 2020-01-20 23:32:21 -08:00
.dir-locals.el Update Emacs configuration 2013-08-13 20:08:44 -04:00
.gitattributes gitattributes: Ignore time zone data files for whitespace checks 2014-07-22 00:12:28 -04:00
.gitignore Add /config.cache to .gitignore in back branches 2017-02-25 13:04:22 -05:00
aclocal.m4 Back-patch updated thread flags tests into 9.4 and 9.5. 2018-11-19 14:24:52 -05:00
configure Stamp 9.4.25. 2019-11-11 17:13:41 -05:00
configure.in Stamp 9.4.25. 2019-11-11 17:13:41 -05:00
COPYRIGHT Update copyrights for 2020 2020-01-01 12:21:44 -05:00
GNUmakefile.in Add TAP tests for client programs 2014-04-14 21:33:46 -04:00
HISTORY Change documentation references to PG website to use https: not http: 2017-05-20 21:50:47 -04:00
Makefile Fix non-GNU makefiles for AIX make. 2017-11-30 00:57:32 -08:00
README Change documentation references to PG website to use https: not http: 2017-05-20 21:50:47 -04:00
README.git Change documentation references to PG website to use https: not http: 2017-05-20 21:50:47 -04:00

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.

PostgreSQL has many language interfaces, many of which are listed here:

	https://www.postgresql.org/download

See the file INSTALL for instructions on how to build and install
PostgreSQL.  That file also lists supported operating systems and
hardware platforms and contains information regarding any other
software packages that are required to build or run the PostgreSQL
system.  Copyright and license information can be found in the
file COPYRIGHT.  A comprehensive documentation set is included in this
distribution; it can be read as described in the installation
instructions.

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