revert before concatenating new entries to preserve the order of orig…

…inal target entries

src/backend/distributed/deparser/citus_ruleutils.c

@@ -1406,7 +1406,12 @@ ExpandMergedSubscriptingRefEntries(List *targetEntryList)
 		}
 		else
 		{
-			newTargetEntryList = list_concat(newTargetEntryList, expandedTargetEntries);
+			/*
+			 * Need to concat expanded target list entries in reverse order
+			 * to preserve ordering of the original target entry list.
+			 */
+			newTargetEntryList = list_concat(newTargetEntryList,
+											 list_reverse(expandedTargetEntries));
 		}
 	}
 

src/backend/distributed/utils/listutils.c

@@ -264,3 +264,20 @@ GenerateListFromElement(void *listElement, int listLength)
 
 	return list;
 }
+
+
+/*
+ * list_reverse returns a new list by reverting order of the elements within
+ * given list.
+ */
+List *
+list_reverse(const List *list)
+{
+	List *newList = NIL;
+	for (int i = list_length(list) - 1; i >= 0; i--)
+	{
+		newList = lappend(newList, list_nth(list, i));
+	}
+
+	return newList;
+}

src/include/distributed/listutils.h

@@ -125,5 +125,6 @@ extern List * ListTake(List *pointerList, int size);
 extern void * safe_list_nth(const List *list, int index);
 extern List * GeneratePositiveIntSequenceList(int upTo);
 extern List * GenerateListFromElement(void *listElement, int listLength);
+extern List * list_reverse(const List *list);
 
 #endif /* CITUS_LISTUTILS_H */

src/test/regress/expected/pg14.out

@@ -1313,5 +1313,39 @@ SELECT * FROM jsonb_subscript_update ORDER BY 1,2;
   4 | {"a": 4, "b": 10}
 (3 rows)
 
+CREATE TABLE nested_obj_update(id INT, data JSONB, text_col TEXT);
+SELECT create_distributed_table('nested_obj_update', 'id');
+ create_distributed_table
+---------------------------------------------------------------------
+
+(1 row)
+
+INSERT INTO nested_obj_update VALUES
+  (1, '{"a": [1,2,3], "b": [4,5,6], "c": [7,8,9], "d": [1,2,1,2]}', '4'),
+  (2, '{"a": [10,20,30], "b": [41,51,61], "c": [72,82,92], "d": [11,21,11,21]}', '6');
+UPDATE nested_obj_update
+SET data['a'][0] = (updated_vals.b * 1)::TEXT::JSONB,
+    data['b'][2] = (updated_vals.c * 2)::TEXT::JSONB,
+    data['c'][0] = (updated_vals.d * 3)::TEXT::JSONB,
+    text_col = (nested_obj_update.id*1000)::TEXT,
+    data['a'][0] = (text_col::INT * data['a'][0]::INT)::TEXT::JSONB,
+    data['d'][6] = (nested_obj_update.id*1)::TEXT::JSONB,
+    data['d'][4] = (nested_obj_update.id*2)::TEXT::JSONB
+FROM (
+  SELECT id,
+         data['a'][0] AS a,
+         data['b'][0]::NUMERIC + 1 AS b,
+         data['c'][0]::NUMERIC + 2 AS c,
+         data['c'][1]::NUMERIC + 3 AS d
+  FROM nested_obj_update
+) updated_vals
+WHERE nested_obj_update.id = updated_vals.id;
+SELECT * FROM nested_obj_update ORDER BY 1,2,3;
+ id |                                              data                                              | text_col
+---------------------------------------------------------------------
+  1 | {"a": [4, 2, 3], "b": [4, 5, 18], "c": [33, 8, 9], "d": [1, 2, 1, 2, 2, null, 1]}              | 1000
+  2 | {"a": [60, 20, 30], "b": [41, 51, 148], "c": [255, 82, 92], "d": [11, 21, 11, 21, 4, null, 2]} | 2000
+(2 rows)
+
 set client_min_messages to error;
 drop schema pg14 cascade;

src/test/regress/sql/pg14.sql

@@ -673,5 +673,31 @@ DO UPDATE SET data['d']=(jsonb_subscript_update.data['a']::INT*100)::TEXT::JSONB
 
 SELECT * FROM jsonb_subscript_update ORDER BY 1,2;
 
+CREATE TABLE nested_obj_update(id INT, data JSONB, text_col TEXT);
+SELECT create_distributed_table('nested_obj_update', 'id');
+INSERT INTO nested_obj_update VALUES
+  (1, '{"a": [1,2,3], "b": [4,5,6], "c": [7,8,9], "d": [1,2,1,2]}', '4'),
+  (2, '{"a": [10,20,30], "b": [41,51,61], "c": [72,82,92], "d": [11,21,11,21]}', '6');
+
+UPDATE nested_obj_update
+SET data['a'][0] = (updated_vals.b * 1)::TEXT::JSONB,
+    data['b'][2] = (updated_vals.c * 2)::TEXT::JSONB,
+    data['c'][0] = (updated_vals.d * 3)::TEXT::JSONB,
+    text_col = (nested_obj_update.id*1000)::TEXT,
+    data['a'][0] = (text_col::INT * data['a'][0]::INT)::TEXT::JSONB,
+    data['d'][6] = (nested_obj_update.id*1)::TEXT::JSONB,
+    data['d'][4] = (nested_obj_update.id*2)::TEXT::JSONB
+FROM (
+  SELECT id,
+         data['a'][0] AS a,
+         data['b'][0]::NUMERIC + 1 AS b,
+         data['c'][0]::NUMERIC + 2 AS c,
+         data['c'][1]::NUMERIC + 3 AS d
+  FROM nested_obj_update
+) updated_vals
+WHERE nested_obj_update.id = updated_vals.id;
+
+SELECT * FROM nested_obj_update ORDER BY 1,2,3;
+
 set client_min_messages to error;
 drop schema pg14 cascade;