ea1d54288f
The code for wrapping subquery output expressions in PlaceHolderVars believed that if the expression already was a PlaceHolderVar, it was never necessary to wrap that in another one. That's wrong if the expression is underneath an outer join and involves a lateral reference to outside that scope: failing to add an additional PHV risks evaluating the expression at the wrong place and hence not forcing it to null when the outer join should do so. This is an oversight in commit 9e7e29c75, which added logic to forcibly wrap lateral-reference Vars in PlaceHolderVars, but didn't see that the adjacent case for PlaceHolderVars needed the same treatment. The test case we have for this doesn't fail before 4be058fe9, but now that I see the problem I wonder if it is possible to demonstrate related errors before that. That's moot though, since all such branches are out of support. Per bug #18284 from Holger Reise. Back-patch to all supported branches. Discussion: https://postgr.es/m/18284-47505a20c23647f8@postgresql.org
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/.