Fixed a crash with pbxt.subselect when 'derived_merge' is set off in

the optimizer switch.

mysql-test/suite/pbxt/r/subselect.result

@@ -2627,8 +2627,6 @@ createDate datetime NOT NULL,
 modifyDate timestamp NOT NULL
 );
 INSERT INTO t5 VALUES (5141,12,'2004-08-06','2004-08-06');
-set @save_optimizer_switch=@@optimizer_switch;
-set optimizer_switch='derived_merge=on';
 select
 count(distinct t2.userid) pass,
 groupstuff.*,
@@ -2670,7 +2668,6 @@ pass	userid	parentid	parentgroup	childid	groupname	grouptypeid	crse	categoryid	c
 1	5141	12	group2	12	group2	5	1	1	87	Oct04
 1	5141	12	group2	12	group2	5	1	2	88	Oct04
 1	5141	12	group2	12	group2	5	1	2	89	Oct04
-set optimizer_switch=@save_optimizer_switch;
 drop table t1, t2, t3, t4, t5;
 create table t1 (a int);
 insert into t1 values (1), (2), (3);

mysql-test/suite/pbxt/t/subselect.test

@@ -1674,9 +1674,6 @@ CREATE TABLE t5 (
 );
 INSERT INTO t5 VALUES (5141,12,'2004-08-06','2004-08-06');
 
-set @save_optimizer_switch=@@optimizer_switch;
-set optimizer_switch='derived_merge=on';
-
 select
   count(distinct t2.userid) pass,
   groupstuff.*,
@@ -1709,8 +1706,6 @@ join
 group by 
   groupstuff.groupname, colhead , t2.courseid;
 
-set optimizer_switch=@save_optimizer_switch; 
-
 drop table t1, t2, t3, t4, t5;
 
 #

sql/sql_select.cc

@@ -5365,7 +5365,7 @@ best_access_path(JOIN      *join,
     /* Estimate the cost of  the hash join access to the table */
     ha_rows rnd_records= matching_candidates_in_table(s, found_constraint);
 
-    tmp= s->quick ? s->quick->read_time : s->table->file->scan_time();
+    tmp= s->quick ? s->quick->read_time : s->scan_time();
     tmp+= (s->records - rnd_records)/(double) TIME_FOR_COMPARE;
 
     /* We read the table as many times as join buffer becomes full. */