In a procedure or function returning tuple, we use that function to parse the Tcl script's result, which is supposed to be a Tcl list. If it isn't, you get an error. Commit 26abb50c4 incautiously supposed that we could use throw_tcl_error() to report such an error. That doesn't actually work, because low-level functions like Tcl_ListObjGetElements() don't fill Tcl's errorInfo variable. The result is either a null-pointer-dereference crash or emission of misleading context information describing the previous Tcl error. Back off to just reporting the interpreter's result string, and improve throw_tcl_error()'s comment to explain when to use it. Also, although the similar code in pltcl_trigger_handler() avoided this mistake, it was using a fairly confusing wording of the error message. Improve that while we're here. Per report from A. Kozhemyakin. Back-patch to all supported branches. Erik Wienhold and Tom Lane Discussion: https://postgr.es/m/6a2a1c40-2b2c-4a33-8b72-243c0766fcda@postgrespro.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/.