Daemon crash when querying numeric `Vec`s other than `<u8>` over PG Wire

[egormanga]

Setup (v1.11.2):

#[table(name=test)]
struct Test {
	a: Vec<u16>,  // i8 does it as well
}

#[reducer(init)]
fn init(ctx: &ReducerContext) {
	ctx.db.test().insert(Test {
		a: vec![1, 2],
	});
}

Reproduction (via psql):

SELECT * FROM test;

Result:

thread 'tokio-runtime-worker' panicked at pgwire-0.34.2/src/api/results.rs:257:36:
index out of bounds: the len is 6 but the index is 6
stack backtrace:
   0: __rustc::rust_begin_unwind
   1: core::panicking::panic_fmt
   2: core::panicking::panic_bounds_check
   3: pgwire::api::results::DataRowEncoder::encode_field
   4: <spacetimedb_pg::encoder::PsqlFormatter as spacetimedb_sats::satn::TypedWriter>::write
   5: spacetimedb_sats::ser::impls::<impl spacetimedb_sats::ser::Serialize for spacetimedb_sats::ValueWithType<spacetimedb_sats::array_value::ArrayValue>>::serialize
   6: spacetimedb_sats::ser::impls::<impl spacetimedb_sats::ser::Serialize for spacetimedb_sats::ValueWithType<spacetimedb_sats::algebraic_value::AlgebraicValue>>::serialize
   7: spacetimedb_pg::pg_server::to_rows
   8: <spacetimedb_pg::pg_server::PgSpacetimeDB<T> as pgwire::api::query::SimpleQueryHandler>::do_query::{{closure}}
   9: pgwire::api::query::SimpleQueryHandler::_on_query::{{closure}}
  10: pgwire::api::query::SimpleQueryHandler::on_query::{{closure}}
  11: spacetimedb_pg::pg_server::start_pg::{{closure}}::{{closure}}

• Discovered while investigating Bug: Vec<u64> column is displayed ambiguously in spacetime sql #3993

[egormanga]

This is probably caused by the statefulness of the pgwire::DataRowEncoder that increments self.col_index after each written value, meaning arrays should be serialized in one call as opposed to SATN's naive one-by-one implementation with the default encoder (which makes it compatible only with that).

I assume this sequential behavior is also what caused #3993 in the first place.

[egormanga]

• Partially related to Panic in BSATN Deserializer via Invalid Type Reference #4001

[bfops]

Thank you for reporting this! We'll work on getting it triaged + fixed.