Fix getting heap tuple size

Also change corresponding tests to what they were originally in fd546cf

src/backend/distributed/executor/tuple_destination.c

@@ -109,7 +109,7 @@ TupleStoreTupleDestPutTuple(TupleDestination *self, Task *task,
 	uint64 tupleSize = tupleLibpqSize;
 	if (tupleSize == 0)
 	{
-		tupleSize = HeapTupleHeaderGetDatumLength(heapTuple);
+		tupleSize = heapTuple->t_len;
 	}
 
 	/*

src/test/regress/citus_tests/run_test.py

@@ -203,6 +203,7 @@ DEPS = {
     "foreign_key_to_reference_shard_rebalance": TestDeps(
         "minimal_schedule", ["remove_coordinator_from_metadata"]
     ),
+    "limit_intermediate_size": TestDeps("base_schedule"),
 }
 
 

src/test/regress/expected/limit_intermediate_size.out

@@ -16,7 +16,8 @@ SELECT cte.user_id, cte.value_2 FROM cte,cte2 ORDER BY 1,2 LIMIT 10;
 ERROR:  the intermediate result size exceeds citus.max_intermediate_result_size (currently 2 kB)
 DETAIL:  Citus restricts the size of intermediate results of complex subqueries and CTEs to avoid accidentally pulling large result sets into once place.
 HINT:  To run the current query, set citus.max_intermediate_result_size to a higher value or -1 to disable.
-SET citus.max_intermediate_result_size TO 17;
+SET citus.max_intermediate_result_size TO 9;
+-- regular adaptive executor CTE should fail
 WITH cte AS MATERIALIZED
 (
 	SELECT
@@ -38,20 +39,9 @@ FROM
 ORDER BY
 	1,2
 LIMIT 10;
- user_id | value_2
----------------------------------------------------------------------
-       1 |       0
-       1 |       0
-       1 |       0
-       1 |       0
-       1 |       0
-       1 |       0
-       1 |       0
-       1 |       0
-       1 |       0
-       1 |       0
-(10 rows)
-
+ERROR:  the intermediate result size exceeds citus.max_intermediate_result_size (currently 9 kB)
+DETAIL:  Citus restricts the size of intermediate results of complex subqueries and CTEs to avoid accidentally pulling large result sets into once place.
+HINT:  To run the current query, set citus.max_intermediate_result_size to a higher value or -1 to disable.
 -- router queries should be able to get limitted too
 SET citus.max_intermediate_result_size TO 2;
 -- this should pass, since we fetch small portions in each subplan
@@ -117,11 +107,9 @@ WITH cte AS MATERIALIZED (
 	AND EXISTS (select * from cte2, cte3)
 )
 SELECT count(*) FROM cte WHERE EXISTS (select * from cte);
- count
----------------------------------------------------------------------
-   105
-(1 row)
-
+ERROR:  the intermediate result size exceeds citus.max_intermediate_result_size (currently 4 kB)
+DETAIL:  Citus restricts the size of intermediate results of complex subqueries and CTEs to avoid accidentally pulling large result sets into once place.
+HINT:  To run the current query, set citus.max_intermediate_result_size to a higher value or -1 to disable.
 SET citus.max_intermediate_result_size TO 3;
 -- this should fail since the cte-subplan exceeds the limit even if the
 -- cte2 and cte3 does not

src/test/regress/sql/limit_intermediate_size.sql

@@ -17,7 +17,8 @@ cte2 AS MATERIALIZED (
 SELECT cte.user_id, cte.value_2 FROM cte,cte2 ORDER BY 1,2 LIMIT 10;
 
 
-SET citus.max_intermediate_result_size TO 17;
+SET citus.max_intermediate_result_size TO 9;
+-- regular adaptive executor CTE should fail
 WITH cte AS MATERIALIZED
 (
 	SELECT