[MDEV-5078] Incorrect 'Subquery returns more than 1 row' - Jira

Subquery in result column complains about returning multiple rows even though an aggregation is done over the rows.

CREATE TABLE t1 (

  a INT(11)

);

INSERT INTO t1 (a) VALUES (1), (2);

CREATE TABLE t2 (

  b INT(11)

);

INSERT INTO t2 (b) VALUES (1), (2);

SELECT

a,

    SELECT

      SUM(a + c)

    FROM

        SELECT

          b as c

        FROM

t2

      ) AS v1

FROM

t1;

Result:

ERROR 1242 (21000): Subquery returns more than 1 row

Expected

a   subquery

1   5

2   7

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