2 files changed, 70 insertions, 0 deletions
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 4051c31ef49..e2cb57097d2 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -2193,6 +2193,56 @@ SELECT '{"a":[1,2,{"c":3,"x":4}],"c":"b"}'::jsonb @> '{"a":[{"x":4},1]}';
  t
 (1 row)
 
+-- check some corner cases for indexed nested containment (bug #13756)
+create temp table nestjsonb (j jsonb);
+insert into nestjsonb (j) values ('{"a":[["b",{"x":1}],["b",{"x":2}]],"c":3}');
+insert into nestjsonb (j) values ('[[14,2,3]]');
+insert into nestjsonb (j) values ('[1,[14,2,3]]');
+create index on nestjsonb using gin(j jsonb_path_ops);
+set enable_seqscan = on;
+set enable_bitmapscan = off;
+select * from nestjsonb where j @> '{"a":[[{"x":2}]]}'::jsonb;
+                         j                         
+---------------------------------------------------
+ {"a": [["b", {"x": 1}], ["b", {"x": 2}]], "c": 3}
+(1 row)
+
+select * from nestjsonb where j @> '{"c":3}';
+                         j                         
+---------------------------------------------------
+ {"a": [["b", {"x": 1}], ["b", {"x": 2}]], "c": 3}
+(1 row)
+
+select * from nestjsonb where j @> '[[14]]';
+        j        
+-----------------
+ [[14, 2, 3]]
+ [1, [14, 2, 3]]
+(2 rows)
+
+set enable_seqscan = off;
+set enable_bitmapscan = on;
+select * from nestjsonb where j @> '{"a":[[{"x":2}]]}'::jsonb;
+                         j                         
+---------------------------------------------------
+ {"a": [["b", {"x": 1}], ["b", {"x": 2}]], "c": 3}
+(1 row)
+
+select * from nestjsonb where j @> '{"c":3}';
+                         j                         
+---------------------------------------------------
+ {"a": [["b", {"x": 1}], ["b", {"x": 2}]], "c": 3}
+(1 row)
+
+select * from nestjsonb where j @> '[[14]]';
+        j        
+-----------------
+ [[14, 2, 3]]
+ [1, [14, 2, 3]]
+(2 rows)
+
+reset enable_seqscan;
+reset enable_bitmapscan;
 -- nested object field / array index lookup
 SELECT '{"n":null,"a":1,"b":[1,2],"c":{"1":2},"d":{"1":[2,3]}}'::jsonb -> 'n';
  ?column? 
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index 1c58b5cda92..74d34dcab4f 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -488,6 +488,26 @@ SELECT '{"a":[1,2,{"c":3,"x":4}],"c":"b"}'::jsonb @> '{"a":[{"x":4}]}';
 SELECT '{"a":[1,2,{"c":3,"x":4}],"c":"b"}'::jsonb @> '{"a":[{"x":4},3]}';
 SELECT '{"a":[1,2,{"c":3,"x":4}],"c":"b"}'::jsonb @> '{"a":[{"x":4},1]}';
 
+-- check some corner cases for indexed nested containment (bug #13756)
+create temp table nestjsonb (j jsonb);
+insert into nestjsonb (j) values ('{"a":[["b",{"x":1}],["b",{"x":2}]],"c":3}');
+insert into nestjsonb (j) values ('[[14,2,3]]');
+insert into nestjsonb (j) values ('[1,[14,2,3]]');
+create index on nestjsonb using gin(j jsonb_path_ops);
+
+set enable_seqscan = on;
+set enable_bitmapscan = off;
+select * from nestjsonb where j @> '{"a":[[{"x":2}]]}'::jsonb;
+select * from nestjsonb where j @> '{"c":3}';
+select * from nestjsonb where j @> '[[14]]';
+set enable_seqscan = off;
+set enable_bitmapscan = on;
+select * from nestjsonb where j @> '{"a":[[{"x":2}]]}'::jsonb;
+select * from nestjsonb where j @> '{"c":3}';
+select * from nestjsonb where j @> '[[14]]';
+reset enable_seqscan;
+reset enable_bitmapscan;
+
 -- nested object field / array index lookup
 SELECT '{"n":null,"a":1,"b":[1,2],"c":{"1":2},"d":{"1":[2,3]}}'::jsonb -> 'n';
 SELECT '{"n":null,"a":1,"b":[1,2],"c":{"1":2},"d":{"1":[2,3]}}'::jsonb -> 'a';