bug#3681 - order by, distinct, refer to aliased field by name

check for field_name (not only for name) in find_item_in_list, to be compatible with item->eq() that is done later

mysql-test/r/order_by.result

@@ -89,10 +89,10 @@ create table t1 ( pk     int primary key, name   varchar(255) not null, number v
 insert into t1 values (1, 'Gamma',     '123'), (2, 'Gamma Ext', '123a'), (3, 'Alpha',     '001'), (4, 'Beta',      '200c');
 select distinct t1.name as 'Building Name',t1.number as 'Building Number' from t1 order by t1.name asc;
 Building Name	Building Number
-Gamma	123
-Gamma Ext	123a
 Alpha	001
 Beta	200c
+Gamma	123
+Gamma Ext	123a
 drop table t1;
 create table t1 (id int not null,col1 int not null,col2 int not null,index(col1));
 insert into t1 values(1,2,2),(2,2,1),(3,1,2),(4,1,1),(5,1,4),(6,2,3),(7,3,1),(8,2,4);

sql/sql_base.cc

@@ -2103,7 +2103,9 @@ find_item_in_list(Item *find, List<Item> &items, uint *counter,
 	=> we have to check presence of name before compare
       */ 
       if (item_field->name &&
-	  !my_strcasecmp(system_charset_info, item_field->name, field_name))
+	  (!my_strcasecmp(system_charset_info, item_field->name, field_name) ||
+           !my_strcasecmp(system_charset_info,
+                          item_field->field_name, field_name)))
       {
 	if (!table_name)
 	{