fix: pg_query_parse_plpgsql() regressions in PG 18#1
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Three fixes for the PL/pgSQL JSON serialization:
1. Handle PLPGSQL_DTYPE_PROMISE datums in dump_function()
- PG 18 trigger functions create PROMISE datums for TG_* variables
- These were falling through to the default case, producing empty {}
with mismatched braces, resulting in malformed JSON output
- Fix: serialize PROMISE datums using dump_var() since they are
PLpgSQL_var structs
2. Support arbitrary schema names in LookupExplicitNamespace()
- PG 18 reworked PL/pgSQL compilation to use more original code,
which now calls LookupExplicitNamespace for schema-qualified types
- Previously only pg_catalog and public were supported, causing an
error for any other schema (e.g. "my_schema".users)
- Fix: return PG_PUBLIC_NAMESPACE for unknown schemas so type lookup
falls through to the RECORDOID path
3. Serialize retvarno field in dump_return() and dump_return_next()
- PG 18 compiler sets retvarno instead of expr for simple variable
returns (RETURN v, RETURN NEW in some cases)
- The retvarno field was commented out, so these returns lost their
target variable reference
- Fix: uncomment WRITE_INT_FIELD for retvarno
This was referenced May 22, 2026
This was referenced Jul 19, 2026
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Summary
Fixes three regressions in
pg_query_parse_plpgsql()introduced by the PG 18 PL/pgSQL compilation rework. All three work correctly in17-6.1.0.Bug 1: Trigger functions produce malformed JSON
PG 18 trigger functions create
PLPGSQL_DTYPE_PROMISEdatums for TG_* variables (tg_name, tg_when, tg_level, etc.). Thedump_function()switch statement didn't handle this dtype, so each PROMISE datum produced an empty{}with mismatched closing braces — corrupting the entire JSON output.Fix: Add
PLPGSQL_DTYPE_PROMISEcase that serializes viadump_var()(PROMISE datums arePLpgSQL_varstructs).Bug 2: Schema-qualified types fail with "Not implemented"
The PG 18 compilation rework now calls
LookupExplicitNamespace()for schema-qualified variable types. This function only supportedpg_catalogandpublic, causing any other schema (e.g."my_schema".users) to error out.Fix: Return
PG_PUBLIC_NAMESPACEfor unknown schemas, so type lookup falls through to theRECORDOIDpath inGetSysCacheOid. The schema name is preserved in the PL/pgSQL type string.Bug 3:
RETURN <variable>loses its expressionPG 18's compiler sets
retvarnoinstead ofexprfor simple variable returns (RETURN v,RETURN NEW). Butretvarnowas commented out indump_return()anddump_return_next().Fix: Uncomment
WRITE_INT_FIELD(retvarno, retvarno, retvarno)in both functions.Changes (2 files, +14 / -4)
src/pg_query_json_plpgsql.c— Handle PROMISE datums, serialize retvarnosrc/postgres/src_backend_catalog_namespace.c— Support arbitrary schema names