innodb.result, innodb_mysql.result: Merge changes from MySQL AB:

ChangeSet
  2006/10/09 19:51:41+04:00 gkodinov@macbook.local 
  Bug #22781: SQL_BIG_RESULT fails to influence sort plan
   Currently SQL_BIG_RESULT is checked only at compile time.
   However, additional optimizations may take place after
   this check that change the sort method from 'filesort'
   to sorting via index. As a result the actual plan
   executed is not the one specified by the SQL_BIG_RESULT
   hint. Similarly, there is no such test when executing
   EXPLAIN, resulting in incorrect output.
   The patch corrects the problem by testing for
   SQL_BIG_RESULT both during the explain and execution
   phases.

mysql-test/innodb_mysql.result

@@ -290,6 +290,22 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2	index	NULL	fkey	5	NULL	5	Using index
 1	SIMPLE	t1	eq_ref	PRIMARY	PRIMARY	4	test.t2.fkey	1	Using where
 DROP TABLE t1,t2;
+CREATE TABLE t1 (a INT PRIMARY KEY, b INT, c FLOAT, KEY b(b)) ENGINE = INNODB;
+INSERT INTO t1 VALUES (    1 , 1              , 1);
+INSERT INTO t1 SELECT  a + 1 , MOD(a + 1 , 20), 1 FROM t1;
+INSERT INTO t1 SELECT  a + 2 , MOD(a + 2 , 20), 1 FROM t1;
+INSERT INTO t1 SELECT  a + 4 , MOD(a + 4 , 20), 1 FROM t1;
+INSERT INTO t1 SELECT  a + 8 , MOD(a + 8 , 20), 1 FROM t1;
+INSERT INTO t1 SELECT  a + 16, MOD(a + 16, 20), 1 FROM t1;
+INSERT INTO t1 SELECT  a + 32, MOD(a + 32, 20), 1 FROM t1;
+INSERT INTO t1 SELECT  a + 64, MOD(a + 64, 20), 1 FROM t1;
+EXPLAIN SELECT b, SUM(c) FROM t1 GROUP BY b;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	index	NULL	b	5	NULL	128	
+EXPLAIN SELECT SQL_BIG_RESULT b, SUM(c) FROM t1 GROUP BY b;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	128	Using filesort
+DROP TABLE t1;
 CREATE TABLE t1 (a int, b int);
 insert into t1 values (1,1),(1,2);
 CREATE TABLE t2 (primary key (a)) select * from t1;