2323f03a17
On v18 and below, if the newest multixid's members end exactly at the
the 32-bit offset wraparound point, the next offset in the control
file is 0. GetOldMultiXactIdSingleMember() treated that as an invalid
entry and dropped the multixid's members, so after upgrade accessing
the tuple failed with "MultiXact N has invalid offset".
To fix, only check for zero offset when it was read from the next
multixid's slot, like GetMultiXactIdMembers() did in v18. This is
unlikely to happen in practice, but better to get it right.
The bug came with commit bd8d9c9bdf in v19.
Author: Zsolt Parragi <zsolt.parragi@percona.com>
Discussion: https://www.postgresql.org/message-id/CAN4CZFM8BCazGz6s1Vn5tMEXYiXE2fi8T2rwmwXSty5gD+h9rA@mail.gmail.com
Backpatch-through: 19
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/.