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Up to now, the "child" executor state trees generated for EvalPlanQual rechecks have simply shared the ResultRelInfo arrays used for the original execution tree. However, this leads to dangling-pointer problems, because ExecInitModifyTable() is all too willing to scribble on some fields of the ResultRelInfo(s) even when it's being run in one of those child trees. This trashes those fields from the perspective of the parent tree, because even if the generated subtree is logically identical to what was in use in the parent, it's in a memory context that will go away when we're done with the child state tree. We do however want to share information in the direction from the parent down to the children; in particular, fields such as es_instrument *must* be shared or we'll lose the stats arising from execution of the children. So the simplest fix is to make a copy of the parent's ResultRelInfo array, but not copy any fields back at end of child execution. Per report from Manuel Kniep. The added isolation test is based on his example. In an unpatched memory-clobber-enabled build it will reliably fail with "ctid is NULL" errors in all branches back to 9.1, as a consequence of junkfilter->jf_junkAttNo being overwritten with $7f7f. This test cannot be run as-is before that for lack of WITH syntax; but I have no doubt that some variant of this problem can arise in older branches, so apply the code change all the way back.
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. 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/.