10685ec082
This improves on commit 51fed14d73ed3acd2282b531fb1396877e44e86a by eliminating the assumption that we can form <some pointer value> + <some offset> without overflow. The entire point of those tests is that we don't trust the offset value, so coding them in a way that could wrap around if the buffer happens to be near the top of memory doesn't seem sound. Instead, track the remaining space as a size_t variable and compare offsets against that. Also, improve comment about why we need the extra early check on xl_tot_len.
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/.