merging

mysql-test/r/show_check.result:
  Auto merged
sql/sql_select.cc:
  Auto merged

mysql-test/r/func_group.result

@@ -733,6 +733,15 @@ one	2
 two	2
 three	1
 drop table t1;
+create table t1(a int, b datetime);
+insert into t1 values (1, NOW()), (2, NOW());
+create table t2 select MAX(b) from t1 group by a;
+show create table t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `MAX(b)` datetime default NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+drop table t1, t2;
 create table t1(f1 datetime);
 insert into t1 values (now());
 create table t2 select f2 from (select max(now()) f2 from t1) a;

mysql-test/r/show_check.result

@@ -250,9 +250,11 @@ type_bool	type_tiny	type_short	type_mediumint	type_bigint	type_decimal	type_nume
 drop table t1;
 create table t1 (a int not null);
 create table t2 select max(a) from t1;
+Warnings:
+Warning	1263	Data truncated; NULL supplied to NOT NULL column 'max(a)' at row 1
 show columns from t2;
 Field	Type	Null	Key	Default	Extra
-max(a)	bigint(20)	YES		NULL	
+max(a)	int(11)			0	
 drop table t1,t2;
 create table t1 (c decimal, d double, f float, r real);
 show columns from t1;

mysql-test/t/func_group.test

@@ -474,6 +474,15 @@ INSERT INTO t1 VALUES
 select val, count(*) from t1 group by val;
 drop table t1;
 
+#
+# Bug #5615: type of aggregate function column wrong when using group by
+#
+
+create table t1(a int, b datetime);
+insert into t1 values (1, NOW()), (2, NOW());
+create table t2 select MAX(b) from t1 group by a;
+show create table t2;
+drop table t1, t2;
 
 #
 # Bug 7833:  Wrong datatype of aggregate column is returned

sql/sql_select.cc

@@ -4771,6 +4771,15 @@ Field *create_tmp_field(THD *thd, TABLE *table,Item *item, Item::Type type,
 				item->name,table,item_sum->decimals);
     case Item_sum::UNIQUE_USERS_FUNC:
       return new Field_long(9,maybe_null,item->name,table,1);
+    case Item_sum::MIN_FUNC:
+    case Item_sum::MAX_FUNC:
+      if (item_sum->args[0]->type() == Item::FIELD_ITEM)
+      {
+        *from_field= ((Item_field*) item_sum->args[0])->field;
+        return create_tmp_field_from_field(thd, *from_field, item, table,
+                                           modify_item, convert_blob_length);
+      }
+      /* fall through */
     default:
       switch (item_sum->result_type()) {
       case REAL_RESULT: