FT.AGGREGATE prints extra fields

[BagritsevichStepan]

FT.AGGREGATE sometimes prints extra fields

Initialize:

127.0.0.1:6379> JSON.SET j1 $ '{"a":"1","b":"2","c":"3"}'
OK
127.0.0.1:6379> JSON.SET j2 $ '{"a":"4","b":"5","c":"6"}'
OK
127.0.0.1:6379> JSON.SET j3 $ '{"a":"7","b":"8","c":"9"}'
OK
127.0.0.1:6379> FT.CREATE index ON JSON SCHEMA $.a AS a TEXT SORTABLE $.b AS b TEXT $.c AS c TEXT
OK

Redis:

127.0.0.1:6379> FT.AGGREGATE index "*"
1) (integer) 1
2) (empty array)
3) (empty array)
4) (empty array)
127.0.0.1:6379> FT.AGGREGATE index "*" SORTBY 1 @a
1) (integer) 3
2) 1) "a"
   2) "1"
3) 1) "a"
   2) "4"
4) 1) "a"
   2) "7"

Dragonfly:

127.0.0.1:6379> ft.aggregate index "*"
1) (integer) 3
2) 1) "a"
   2) "\"b\""
   3) "b"
   4) "\"1\""
3) 1) "a"
   2) "\"cc\""
   3) "b"
   4) "\"2\""
4) 1) "a"
   2) "\"ddd\""
   3) "b"
   4) "\"3\""
127.0.0.1:6379> ft.aggregate index "*" SORTBY 1 a
1) (integer) 3
2) 1) "a"
   2) "\"b\""
   3) "b"
   4) "\"1\""
3) 1) "a"
   2) "\"cc\""
   3) "b"
   4) "\"2\""
4) 1) "a"
   2) "\"ddd\""
   3) "b"
   4) "\"3\""