mirror of
https://github.com/postgres/postgres.git
synced 2025-06-19 04:21:08 +03:00
7da51590ed
Here we fix a faulty "if" condition which failed to correctly handle two
or more consecutive NULL transition values when checking if the new value
is DISTINCT from the old value for presorted aggregates. Given a suitably
non-strict aggregate transition function, a byref aggregate could cause a
crash due to calling the type's equality function and passing along a
(Datum) 0 value to test for equality, the equality function would then try
to dereference that 0 Datum and segfault. For byval types, there'd have
been no crash and the equality function would have seen that the two 0
Datums matched, which (only by chance) meant the calling code would have
worked correctly.
Here we ensure that we only call the equality function when neither of
the input values are NULL.
This code is all new as of 1349d2790, so no backpatch needed.
Reported-by: Fujii Masao
Discussion: https://postgr.es/m/860c6d6f-a3c5-3ae9-9da2-827177bede06@oss.nttdata.com
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/.