07aeb1fec5
HeapTupleSatisfiesUpdate can very easily "forget" tuple locks while checking the contents of a multixact and finding it contains an aborted update, by setting the HEAP_XMAX_INVALID bit. This would lead to concurrent transactions not noticing any previous locks held by transactions that might still be running, and thus being able to acquire subsequent locks they wouldn't be normally able to acquire. This bug was introduced in commit 1ce150b7bb; backpatch this fix to 9.3, like that commit. This change reverts the change to the delete-abort-savept isolation test in 1ce150b7bb, because that behavior change was caused by this bug. Noticed by Andres Freund while investigating a different issue reported by Noah Misch.
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: http://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. Changes between all PostgreSQL releases are recorded in the file HISTORY. 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 http://www.postgresql.org/download/. For more information look at our web site located at http://www.postgresql.org/.