Fix for BUG#8579 (failing test case): Allow small differences in #rows estimate in test results

mysql-test/r/index_merge_ror_cpk.result

@@ -59,7 +59,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ref	key1	key1	4	const	100	Using where
 explain select * from t1 where pk1 < 7500 and key1 = 10;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	index_merge	PRIMARY,key1	key1,PRIMARY	4,4	NULL	38	Using intersect(key1,PRIMARY); Using where
+1	SIMPLE	t1	index_merge	PRIMARY,key1	key1,PRIMARY	4,4	NULL	ROWS	Using intersect(key1,PRIMARY); Using where
 explain select * from t1 where pktail1ok=1 and key1=10;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	index_merge	key1,pktail1ok	key1,pktail1ok	4,4	NULL	1	Using intersect(key1,pktail1ok); Using where

mysql-test/t/index_merge_ror_cpk.test

@@ -63,6 +63,7 @@ select pk1,pk2 from t1 where key1 = 10 and key2=10 and 2*pk1+1 < 2*96+1;
 # Verify that CPK is always used for index intersection scans
 # (this is because it is used as a filter, not for retrieval)
 explain select * from t1 where badkey=1 and key1=10;
+--replace_result 38 ROWS 37 ROWS
 explain select * from t1 where pk1 < 7500 and key1 = 10;
   
 # Verify that keys with 'tails' of PK members are ok.