Fixed LP bug #999251: Q13 from DBT3 uses table scan instead of covering index scan.

The optimizer chose a less efficient execution plan due to the following
defects of the code:
1. the generic handler function handler::keyread_time did not take into account
   that in clustered primary keys record data is included into each index entry
2. the function make_join_readinfo erroneously decided that index only scan
   could not be used if join cache was empoyed.

Added no additional test case.
Adjusted some of the test results.

1 files changed, 4 insertions, 4 deletions

diff --git a/mysql-test/r/join_cache.result b/mysql-test/r/join_cache.result
index 0892ce7794a..f3d282cd6eb 100644
--- a/mysql-test/r/join_cache.result
+++ b/mysql-test/r/join_cache.result
@@ -3221,7 +3221,7 @@ explain
 select t1.a, count(t2.p) as count
 from t1 left join t2 on t1.a=t2.a and t2.p % 2 = 1 group by t1.a;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	8	Using temporary; Using filesort
+1	SIMPLE	t1	index	NULL	PRIMARY	4	NULL	8	Using index; Using temporary; Using filesort
 1	SIMPLE	t2	ref	i_a	i_a	5	test.t1.a	2	Using where; Using join buffer (flat, BKA join); Key-ordered Rowid-ordered scan
 select t1.a, count(t2.p) as count
 from t1 left join t2 on t1.a=t2.a and t2.p % 2 = 1 group by t1.a;
@@ -4327,15 +4327,15 @@ SELECT t2.v FROM t1, t2, t3
 WHERE t3.v <> t2.v AND t3.pk = t2.i AND t1.v = t3.v AND t1.pk*2<100 
 GROUP BY t2.v ORDER BY t1.pk,t2.v;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	ALL	idx1	NULL	NULL	NULL	20	Using temporary; Using filesort
+1	SIMPLE	t2	index	idx1	idx2	7	NULL	20	Using index; Using temporary; Using filesort
 1	SIMPLE	t3	eq_ref	PRIMARY,idx2	PRIMARY	4	test.t2.i	1	Using where; Using join buffer (flat, BKA join); Key-ordered Rowid-ordered scan
 1	SIMPLE	t1	ref	idx2	idx2	3	test.t3.v	5	Using where; Using join buffer (incremental, BKA join); Key-ordered Rowid-ordered scan
 SELECT t2.v FROM t1, t2, t3 
 WHERE t3.v <> t2.v AND t3.pk = t2.i AND t1.v = t3.v AND t1.pk*2<100 
 GROUP BY t2.v ORDER BY t1.pk,t2.v;
 v
-b
 h
+b
 n
 v
 p
@@ -4345,7 +4345,7 @@ SELECT t2.v FROM t1, t2, t3
 WHERE t3.v <> t2.v AND t3.pk = t2.i AND t1.v = t3.v AND t1.pk*2<100 
 GROUP BY t2.v ORDER BY t1.pk,t2.v;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	ALL	idx1	NULL	NULL	NULL	20	Using temporary; Using filesort
+1	SIMPLE	t2	index	idx1	idx2	7	NULL	20	Using index; Using temporary; Using filesort
 1	SIMPLE	t3	hash_ALL	PRIMARY,idx2	#hash#PRIMARY	4	test.t2.i	20	Using where; Using join buffer (flat, BNLH join)
 1	SIMPLE	t1	hash_ALL	idx2	#hash#idx2	3	test.t3.v	45	Using where; Using join buffer (incremental, BNLH join)
 SELECT t2.v FROM t1, t2, t3