pgsql: SQL/JSON: Always coerce JsonExpr result at runtime

SQL/JSON: Always coerce JsonExpr result at runtime

Instead of looking up casts at parse time for converting the result
of JsonPath* query functions to the specified or the default
RETURNING type, always perform the conversion at runtime using either
the target type's input function or the function
json_populate_type().

There are two motivations for this change:

1. json_populate_type() coerces to types with typmod such that any
string values that exceed length limit cause an error instead of
silent truncation, which is necessary to be standard-conforming.

2. It was possible to end up with a cast expression that doesn't
support soft handling of errors causing bugs in the of handling
ON ERROR clause.

JsonExpr.coercion_expr which would store the cast expression is no
longer necessary, so remove.

Bump catversion because stored rules change because of the above
removal.

Reported-by: Alvaro Herrera <alvherre(at)alvh(dot)no-ip(dot)org>
Reviewed-by: Jian He <jian(dot)universality(at)gmail(dot)com>
Discussion: Discussion: https://postgr.es/m/202405271326.5a5rprki64aw%40alvherre.pgsql

Branch
------
master

Details
-------
https://git.postgresql.org/pg/commitdiff/716bd12d22c53d1943d41309f2dd061ec601dd5e

Modified Files
--------------
src/backend/executor/execExpr.c | 52 ++-----
src/backend/executor/execExprInterp.c | 51 +++---
src/backend/jit/llvm/llvmjit_expr.c | 2 +-
src/backend/nodes/nodeFuncs.c | 13 +-
src/backend/parser/parse_expr.c | 188 +++++------------------
src/backend/utils/adt/jsonfuncs.c | 48 ++++--
src/include/catalog/catversion.h | 2 +-
src/include/executor/execExpr.h | 1 +
src/include/nodes/execnodes.h | 5 +-
src/include/nodes/primnodes.h | 8 +-
src/include/utils/jsonfuncs.h | 1 +
src/test/regress/expected/sqljson_jsontable.out | 52 +++----
src/test/regress/expected/sqljson_queryfuncs.out | 72 ++++++---
src/test/regress/sql/sqljson_jsontable.sql | 2 +-
src/test/regress/sql/sqljson_queryfuncs.sql | 25 ++-
15 files changed, 213 insertions(+), 309 deletions(-)