* Undo of range optimizer fix from previous changeset

 * Fixed test results.


mysql-test/r/index_merge_ror.result:
  Typo fix
mysql-test/r/rowid_order_bdb.result:
  new index_merge EXPLAIN output format changes
mysql-test/r/rowid_order_innodb.result:
  new index_merge EXPLAIN output format changes
sql/opt_range.cc:
  Undo of previous fix:
  If cost(full_scan_on_covering_index) < cost(best_range_scan) <  cost(full_table_scan) 
  use full_scan_on_covering_index, not best_range_scan.
  The fix affects read plan choice for more queries then initially anticipated, so I'm reverting it for now, will get back to this later

mysql-test/r/index_merge_ror.result

@@ -193,3 +193,4 @@ insert into t2 values ('ab', 'ab', 'uh', 'oh');
 explain select a from t2 where a='ab';
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2	ref	a	a	6	const	1	Using where
+drop table t2;

mysql-test/r/rowid_order_bdb.result

@@ -14,7 +14,7 @@ insert into t1 values (-5, 1, 1),
 (10, 1, 1);
 explain select * from t1 force index(key1, key2) where key1 < 3 or key2 < 3;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	index_merge	key1,key2	key1,key2	5,5	NULL	5	Using where
+1	SIMPLE	t1	index_merge	key1,key2	key1,key2	5,5	NULL	5	Using sort_union(key1,key2); Using where
 select * from t1 force index(key1, key2) where key1 < 3 or key2 < 3;
 pk1	key1	key2
 -100	1	1

mysql-test/r/rowid_order_innodb.result

@@ -14,7 +14,7 @@ insert into t1 values (-5, 1, 1),
 (10, 1, 1);
 explain select * from t1 force index(key1, key2) where key1 < 3 or key2 < 3;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	index_merge	key1,key2	key1,key2	5,5	NULL	6	Using where
+1	SIMPLE	t1	index_merge	key1,key2	key1,key2	5,5	NULL	6	Using sort_union(key1,key2); Using where
 select * from t1 force index(key1, key2) where key1 < 3 or key2 < 3;
 pk1	key1	key2
 -100	1	1

sql/opt_range.cc

@@ -1610,17 +1610,6 @@ int SQL_SELECT::test_quick_select(THD *thd, key_map keys_to_use,
     }
     param.key_parts_end=key_parts;
 
-    /* Calculate cost of full index read for the shortest covering index */
-    if (!head->used_keys.is_clear_all())
-    {           
-      int key_for_use= find_shortest_key(head, &head->used_keys);
-      double key_read_time= get_index_only_read_time(&param, records, 
-                                                     key_for_use);      
-      DBUG_PRINT("info",  ("'all'+'using index' scan will be using key %d, "
-                           "read time %g", key_for_use, key_read_time));
-      if (key_read_time < read_time)
-        read_time= key_read_time;
-    }
           
     if ((tree=get_mm_tree(&param,cond)))
     {
@@ -1683,6 +1672,19 @@ int SQL_SELECT::test_quick_select(THD *thd, key_map keys_to_use,
           SEL_IMERGE *imerge;
           TABLE_READ_PLAN *best_conj_trp= NULL, *new_conj_trp;
           LINT_INIT(new_conj_trp); /* no empty index_merge lists possible */
+
+          /* Calculate cost of full index read for the shortest covering index */
+          if (!head->used_keys.is_clear_all())
+          {           
+            int key_for_use= find_shortest_key(head, &head->used_keys);
+            double key_read_time= get_index_only_read_time(&param, records, 
+                                                           key_for_use);      
+            DBUG_PRINT("info",  ("'all'+'using index' scan will be using key %d, "
+                                 "read time %g", key_for_use, key_read_time));
+            if (key_read_time < read_time)
+              read_time= key_read_time;
+          }
+          
           DBUG_PRINT("info",("No range reads possible,"
                              " trying to construct index_merge"));
           List_iterator_fast<SEL_IMERGE> it(tree->merges);