Fix for bug #8465 (MIN, MAX return incorrect result)

mysql-test/r/func_group.result:
  test result fixed
mysql-test/t/func_group.test:
  testcase added

mysql-test/r/func_group.result

@@ -842,3 +842,16 @@ col1	count(col1)	sum(col1)	avg(col1)
 -5.000000000010	4	-20.000000000040	-5.0000000000100000
 -5.000000000000	2	-10.000000000000	-5.0000000000000000
 DROP TABLE t1;
+create table t1 (col1 decimal(16,12));
+insert into t1 values (-5.00000000001);
+insert into t1 values (-5.00000000001);
+select col1,sum(col1),max(col1),min(col1) from t1 group by col1;
+col1	sum(col1)	max(col1)	min(col1)
+-5.000000000010	-10.000000000020	-5.000000000010	-5.000000000010
+delete from t1;
+insert into t1 values (5.00000000001);
+insert into t1 values (5.00000000001);
+select col1,sum(col1),max(col1),min(col1) from t1 group by col1;
+col1	sum(col1)	max(col1)	min(col1)
+5.000000000010	10.000000000020	5.000000000010	5.000000000010
+DROP TABLE t1;

mysql-test/t/func_group.test

@@ -548,3 +548,16 @@ insert into t1 select * from t1;
 select col1,count(col1),sum(col1),avg(col1) from t1 group by col1;
 DROP TABLE t1;
 
+#
+# BUG#8465 decimal MIN and MAX return incorrect result
+#
+
+create table t1 (col1 decimal(16,12));
+insert into t1 values (-5.00000000001);
+insert into t1 values (-5.00000000001);
+select col1,sum(col1),max(col1),min(col1) from t1 group by col1;
+delete from t1;
+insert into t1 values (5.00000000001);
+insert into t1 values (5.00000000001);
+select col1,sum(col1),max(col1),min(col1) from t1 group by col1;
+DROP TABLE t1;