Bug#27333: subquery grouped for aggregate of outer

query / no aggregate of subquery
 The optimizer counts the aggregate functions that 
 appear as top level expressions (in all_fields) in 
 the current subquery. Later it makes a list of these
 that it uses to actually execute the aggregates in
 end_send_group().
 That count is used in several places as a flag whether
 there are aggregates functions.
 While collecting the above info it must not consider
 aggregates that are not aggregated in the current 
 context. It must treat them as normal expressions 
 instead. Not doing that leads to incorrect data about
 the query, e.g. running a query that actually has no
 aggregate functions as if it has some (and hence is
 expected to return only one row).
 Fixed by ignoring the aggregates that are not aggregated
 in the current context. 
 One other smaller omission discovered and fixed in the 
 process : the place of aggregation was not calculated for
 user defined functions. Fixed by calling 
 Item_sum::init_sum_func_check() and 
 Item_sum::check_sum_func() as it's done for the rest of 
 the aggregate functions.

1 files changed, 42 insertions, 0 deletions

diff --git a/mysql-test/t/subselect.test b/mysql-test/t/subselect.test
index 12688fa4cf4..d076ca6bd33 100644
--- a/mysql-test/t/subselect.test
+++ b/mysql-test/t/subselect.test
@@ -2945,4 +2945,46 @@ SELECT (SELECT 1 FROM  t1 WHERE t1.a=t2.a ORDER BY t1.b LIMIT 1) AS d1 FROM t2;
 
 DROP TABLE t1,t2;
 
+
+#
+# Bug #27333: subquery grouped for aggregate of outer query / no aggregate
+# of subquery
+#
+CREATE TABLE t1 (a INTEGER, b INTEGER);
+CREATE TABLE t2 (x INTEGER);
+INSERT INTO t1 VALUES (1,11), (2,22), (2,22);
+INSERT INTO t2 VALUES (1), (2);
+
+# wasn't failing, but should
+--error ER_SUBQUERY_NO_1_ROW
+SELECT a, COUNT(b), (SELECT COUNT(b) FROM t2) FROM t1 GROUP BY a;
+
+# fails as it should
+--error ER_SUBQUERY_NO_1_ROW
+SELECT a, COUNT(b), (SELECT COUNT(b)+0 FROM t2) FROM t1 GROUP BY a;
+
+SELECT (SELECT SUM(t1.a)/AVG(t2.x) FROM t2) FROM t1;
+DROP TABLE t1,t2;
+
+# second test case from 27333
+CREATE TABLE t1 (a INT, b INT);
+INSERT INTO t1 VALUES (1, 2), (1,3), (1,4), (2,1), (2,2);
+
+-- returns no rows, when it should
+SELECT a1.a, COUNT(*) FROM t1 a1 WHERE a1.a = 1
+AND EXISTS( SELECT a2.a FROM t1 a2 WHERE a2.a = a1.a)
+GROUP BY a1.a;
+DROP TABLE t1;
+
+#test cases from 29297
+CREATE TABLE t1 (a INT);
+CREATE TABLE t2 (a INT);
+INSERT INTO t1 VALUES (1),(2);
+INSERT INTO t2 VALUES (1),(2);
+SELECT (SELECT SUM(t1.a) FROM t2 WHERE a=0) FROM t1;
+--error ER_SUBQUERY_NO_1_ROW
+SELECT (SELECT SUM(t1.a) FROM t2 WHERE a!=0) FROM t1;
+SELECT (SELECT SUM(t1.a) FROM t2 WHERE a=1) FROM t1;
+DROP TABLE t1,t2;
+
 --echo End of 5.0 tests.