Two or more constants can have the same location. We handled this correctly for non squashed constants, but failed to do it if squashed (resulting in out-of-bounds memory access), because the code structure became broken by commit 0f65f3eec478: we failed to update 'last_loc' correctly when skipping these squashed constants. The simplest fix seems to be to get rid of 'last_loc' altogether -- in hindsight, it's quite pointless. Also, when ignoring a constant because of this, make sure to fulfill fill_in_constant_lengths's duty of setting its length to -1. Lastly, we can use == instead of <= because the locations have been sorted beforehand, so the < case cannot arise. Co-authored-by: Sami Imseih <samimseih@gmail.com> Co-authored-by: Dmitry Dolgov <9erthalion6@gmail.com> Reported-by: Konstantin Knizhnik <knizhnik@garret.ru> Backpatch-through: 18 Discussion: https://www.postgresql.org/message-id/2b91e358-0d99-43f7-be44-d2d4dbce37b3%40garret.ru
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/.