addressing review

src/backend/distributed/planner/multi_logical_optimizer.c

@@ -4753,11 +4753,14 @@ WorkerLimitCount(Node *limitCount, Node *limitOffset, OrderByLimitReference
 	if (workerLimitNode != NULL && limitOffset != NULL)
 	{
 		Const *workerLimitConst = (Const *) workerLimitNode;
+
+		/* Only update the worker limit if the const is not null.*/
 		if (!workerLimitConst->constisnull)
 		{
-			/* Only update the worker limit if the const is not null.*/
 			Const *workerOffsetConst = (Const *) limitOffset;
 			int64 workerLimitCount = DatumGetInt64(workerLimitConst->constvalue);
+
+			/* If the offset is null, it defaults to 0 when cast to int64. */
 			int64 workerOffsetCount = DatumGetInt64(workerOffsetConst->constvalue);
 			workerLimitCount = workerLimitCount + workerOffsetCount;
 			workerLimitNode = (Node *) MakeIntegerConstInt64(workerLimitCount);

src/test/regress/expected/multi_limit_clause.out

@@ -578,6 +578,29 @@ DEBUG:  push down of limit count: 1
           1
 (1 row)
 
+-- check if we can correctly push the limit when it is all
+SELECT l_orderkey FROM lineitem WHERE l_orderkey < 2 LIMIT all;
+DEBUG:  push down of limit count: ALL
+ l_orderkey
+---------------------------------------------------------------------
+          1
+          1
+          1
+          1
+          1
+          1
+(6 rows)
+
+SELECT l_orderkey FROM lineitem WHERE l_orderkey < 2 OFFSET 2 LIMIT all;
+DEBUG:  push down of limit count: ALL
+ l_orderkey
+---------------------------------------------------------------------
+          1
+          1
+          1
+          1
+(4 rows)
+
 SET client_min_messages TO NOTICE;
 -- non constants should not push down
 CREATE OR REPLACE FUNCTION my_limit()

src/test/regress/sql/multi_limit_clause.sql

@@ -236,6 +236,11 @@ SELECT l_orderkey FROM lineitem WHERE l_orderkey < 3 ORDER BY l_orderkey OFFSET
 
 SELECT l_orderkey FROM lineitem WHERE l_orderkey < 3 ORDER BY l_orderkey OFFSET null LIMIT 1;
 
+-- check if we can correctly push the limit when it is all
+SELECT l_orderkey FROM lineitem WHERE l_orderkey < 2 LIMIT all;
+
+SELECT l_orderkey FROM lineitem WHERE l_orderkey < 2 OFFSET 2 LIMIT all;
+
 SET client_min_messages TO NOTICE;
 
 -- non constants should not push down