Correctly handle array pseudotypes in to_json and to_jsonb

Columns with array pseudotypes have not been identified as arrays, so
they have been rendered as strings in the json and jsonb conversion
routines. This change allows them to be rendered as json arrays, making
it possible to deal correctly with the anyarray columns in pg_stats.

Author: adunstan

src/backend/utils/adt/json.c

@@ -1397,9 +1397,10 @@ json_categorize_type(Oid typoid,
 
 		default:
 			/* Check for arrays and composites */
-			if (OidIsValid(get_element_type(typoid)))
+			if (OidIsValid(get_element_type(typoid)) || typoid == ANYARRAYOID
+				|| typoid == RECORDARRAYOID)
 				*tcategory = JSONTYPE_ARRAY;
-			else if (type_is_rowtype(typoid))
+			else if (type_is_rowtype(typoid)) /* includes RECORDOID */
 				*tcategory = JSONTYPE_COMPOSITE;
 			else
 			{

src/backend/utils/adt/jsonb.c

@@ -644,9 +644,10 @@ jsonb_categorize_type(Oid typoid,
 
 		default:
 			/* Check for arrays and composites */
-			if (OidIsValid(get_element_type(typoid)))
+			if (OidIsValid(get_element_type(typoid)) || typoid == ANYARRAYOID
+				|| typoid == RECORDARRAYOID)
 				*tcategory = JSONBTYPE_ARRAY;
-			else if (type_is_rowtype(typoid))
+			else if (type_is_rowtype(typoid)) /* includes RECORDOID */
 				*tcategory = JSONBTYPE_COMPOSITE;
 			else
 			{

src/test/regress/expected/json.out

@@ -383,6 +383,15 @@ SELECT row_to_json(row((select array_agg(x) as d from generate_series(5,10) x)),
  {"f1":[5,6,7,8,9,10]}
 (1 row)
 
+-- anyarray column
+select to_json(histogram_bounds) histogram_bounds
+from pg_stats
+where attname = 'tmplname' and tablename = 'pg_pltemplate';
+                                   histogram_bounds                                    
+---------------------------------------------------------------------------------------
+ ["plperl","plperlu","plpgsql","plpython2u","plpython3u","plpythonu","pltcl","pltclu"]
+(1 row)
+
 -- to_json, timestamps
 select to_json(timestamp '2014-05-28 12:22:35.614298');
            to_json            

src/test/regress/expected/jsonb.out

@@ -279,6 +279,15 @@ SELECT array_to_json(ARRAY [jsonb '{"a":1}', jsonb '{"b":[2,3]}']);
  [{"a": 1},{"b": [2, 3]}]
 (1 row)
 
+-- anyarray column
+select to_jsonb(histogram_bounds) histogram_bounds
+from pg_stats
+where attname = 'tmplname' and tablename = 'pg_pltemplate';
+                                       histogram_bounds                                       
+----------------------------------------------------------------------------------------------
+ ["plperl", "plperlu", "plpgsql", "plpython2u", "plpython3u", "plpythonu", "pltcl", "pltclu"]
+(1 row)
+
 -- to_jsonb, timestamps
 select to_jsonb(timestamp '2014-05-28 12:22:35.614298');
            to_jsonb           

src/test/regress/sql/json.sql

@@ -102,6 +102,12 @@ FROM rows q;
 
 SELECT row_to_json(row((select array_agg(x) as d from generate_series(5,10) x)),false);
 
+-- anyarray column
+
+select to_json(histogram_bounds) histogram_bounds
+from pg_stats
+where attname = 'tmplname' and tablename = 'pg_pltemplate';
+
 -- to_json, timestamps
 
 select to_json(timestamp '2014-05-28 12:22:35.614298');

src/test/regress/sql/jsonb.sql

@@ -62,6 +62,12 @@ SELECT '    '::jsonb;			-- ERROR, no value
 -- make sure jsonb is passed through json generators without being escaped
 SELECT array_to_json(ARRAY [jsonb '{"a":1}', jsonb '{"b":[2,3]}']);
 
+-- anyarray column
+
+select to_jsonb(histogram_bounds) histogram_bounds
+from pg_stats
+where attname = 'tmplname' and tablename = 'pg_pltemplate';
+
 -- to_jsonb, timestamps
 
 select to_jsonb(timestamp '2014-05-28 12:22:35.614298');