4c75cc7863
transformJsonBehavior() coerced an ON EMPTY / ON ERROR DEFAULT
expression only when its type differed from the RETURNING type's OID.
When the base type matched but the RETURNING type carried a type
modifier (e.g. numeric(4,1) or varchar(3)), the coercion that enforces
the typmod was skipped, so the DEFAULT value could violate the
declared type:
SELECT JSON_VALUE(jsonb '{}', '$.a'
RETURNING numeric(4,1) DEFAULT 99999.999 ON EMPTY);
returned 99999.999, which 99999.999::numeric(4,1) would reject; the
value could even be stored into a numeric(4,1) column, as later
coercions trust its already-correct type label.
Fix by also coercing when the RETURNING type has a typmod, except for
a NULL constant. coerce_to_target_type() is a no-op when the typmod
already matches. The matching-OID short-circuit dates to 74c96699be.
Reported-by: Ewan Young <kdbase.hack@gmail.com>
Author: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/CAON2xHPO9f4cAmyGn1mQ=VqoS7wN5rz4yOiqudxX78zninZpCw@mail.gmail.com
Backpatch-through: 17
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/.