func appendResult(qr, innerqr *sqltypes.Result) {
	if innerqr.RowsAffected == 0 && len(innerqr.Fields) == 0 {
		return
	}
	if qr.Fields == nil {
		qr.Fields = innerqr.Fields
	}
	qr.RowsAffected += innerqr.RowsAffected
	if innerqr.InsertID != 0 {
		qr.InsertID = innerqr.InsertID
	}
	qr.Rows = append(qr.Rows, innerqr.Rows...)
}

// UnmarshalBson bson-decodes into QueryResultList.
func (queryResultList *QueryResultList) UnmarshalBson(buf *bytes.Buffer, kind byte) {
	switch kind {
	case bson.EOO, bson.Object:
		// valid
	case bson.Null:
		return
	default:
		panic(bson.NewBsonError("unexpected kind %v for QueryResultList", kind))
	}
	bson.Next(buf, 4)

	for kind := bson.NextByte(buf); kind != bson.EOO; kind = bson.NextByte(buf) {
		switch bson.ReadCString(buf) {
		case "List":
			// []sqltypes.Result
			if kind != bson.Null {
				if kind != bson.Array {
					panic(bson.NewBsonError("unexpected kind %v for queryResultList.List", kind))
				}
				bson.Next(buf, 4)
				queryResultList.List = make([]sqltypes.Result, 0, 8)
				for kind := bson.NextByte(buf); kind != bson.EOO; kind = bson.NextByte(buf) {
					bson.SkipIndex(buf)
					var _v1 sqltypes.Result
					_v1.UnmarshalBson(buf, kind)
					queryResultList.List = append(queryResultList.List, _v1)
				}
			}
		case "Err":
			// *mproto.RPCError
			if kind != bson.Null {
				queryResultList.Err = new(mproto.RPCError)
				(*queryResultList.Err).UnmarshalBson(buf, kind)
			}
		default:
			bson.Skip(buf, kind)
		}
	}
}

func appendResult(qr, innerqr *sqltypes.Result) {
	if innerqr.RowsAffected == 0 && len(innerqr.Fields) == 0 {
		return
	}
	if qr.Fields == nil {
		qr.Fields = innerqr.Fields
	}
	qr.RowsAffected += innerqr.RowsAffected
	if innerqr.InsertID != 0 {
		qr.InsertID = innerqr.InsertID
	}
	if len(qr.Rows) == 0 {
		// we haven't gotten any result yet, just save the new extras.
		qr.Extras = innerqr.Extras
	} else {
		// Merge the EventTokens / Fresher flags within Extras.
		if innerqr.Extras == nil {
			// We didn't get any from innerq. Have to clear any
			// we'd have gotten already.
			if qr.Extras != nil {
				qr.Extras.EventToken = nil
				qr.Extras.Fresher = false
			}
		} else {
			// We may have gotten an EventToken from
			// innerqr.  If we also got one earlier, merge
			// it. If we didn't get one earlier, we
			// discard the new one.
			if qr.Extras != nil {
				// Note if any of the two is nil, we get nil.
				qr.Extras.EventToken = eventtoken.Minimum(qr.Extras.EventToken, innerqr.Extras.EventToken)

				qr.Extras.Fresher = qr.Extras.Fresher && innerqr.Extras.Fresher
			}
		}
	}
	qr.Rows = append(qr.Rows, innerqr.Rows...)
}