Aggregation on Nested Array Field return unexpected value

[penghuo]

The aggregatioin on nested array field return unexpected value.
SQL

    SELECT e.name, COUNT(p) as count
    FROM employee_nested_it AS e, e.projects AS p
    GROUP BY e.name

Test data: https://github.com/opendistro-for-elasticsearch/sql/blob/master/src/test/resources/employee_nested.json

Expected Result

      "buckets" : [
        {
          "key" : "Bob Smith",
          "doc_count" : 1,
          "projects@NESTED" : {
            "doc_count" : 3,
            "count" : {
              "value" : 3
            }
          }
        },
        {
          "key" : "Jane Smith",
          "doc_count" : 1,
          "projects@NESTED" : {
            "doc_count" : 2,
            "count" : {
              "value" : 2
            }
          }
        },
        {
          "key" : "John Doe",
          "doc_count" : 1,
          "projects@NESTED" : {
            "doc_count" : 0,
            "count" : {
              "value" : 0
            }
          }
        },
        {
          "key" : "Susan Smith",
          "doc_count" : 1,
          "projects@NESTED" : {
            "doc_count" : 0,
            "count" : {
              "value" : 0
            }
          }
        }
      ]

Actual Result

      "buckets" : [
        {
          "key" : "Bob Smith",
          "doc_count" : 1,
          "projects@NESTED" : {
            "doc_count" : 3,
            "count" : {
              "value" : 0
            }
          }
        },
        {
          "key" : "Jane Smith",
          "doc_count" : 1,
          "projects@NESTED" : {
            "doc_count" : 2,
            "count" : {
              "value" : 0
            }
          }
        },
        {
          "key" : "John Doe",
          "doc_count" : 1,
          "projects@NESTED" : {
            "doc_count" : 0,
            "count" : {
              "value" : 0
            }
          }
        },
        {
          "key" : "Susan Smith",
          "doc_count" : 1,
          "projects@NESTED" : {
            "doc_count" : 0,
            "count" : {
              "value" : 0
            }
          }
        }
     ]