Bug #22367: Optimizer uses ref join type instead of eq_ref for simple join on

             strings
MySQL is setting the flag HA_END_SPACE_KEYS for all the keys that reference
text or varchar columns with collation different than binary.
This was done to handle correctly the situation where a lookup on such a key
may return more than 1 row because of the presence of many rows that differ
only by the amount of trailing space in the table's string column.
Inserting such values however appears to violate the unique checks on 
INSERT/UPDATE. Thus that flag must not be set as it will prevent the optimizer
from choosing a faster access method.
This fix removes the setting of the HA_END_SPACE_KEYS flag.


include/my_base.h:
  Bug #22367: Optimizer uses ref join type instead of eq_ref for simple join on 
               strings
   - disabled HA_END_SPACE_KEY as it's no longer needed
mysql-test/r/func_str.result:
  Bug #22367: Optimizer uses ref join type instead of eq_ref for simple join on 
               strings
   - fixed explain in an existing case
mysql-test/r/merge.result:
  Bug #22367: Optimizer uses ref join type instead of eq_ref for simple join on 
               strings
   - fixed explain in an existing case
mysql-test/r/select.result:
  Bug #22367: Optimizer uses ref join type instead of eq_ref for simple join on 
               strings
   - test case
mysql-test/r/subselect.result:
  Bug #22367: Optimizer uses ref join type instead of eq_ref for simple join on 
               strings
   - fixed explain in an existing case
mysql-test/t/select.test:
  Bug #22367: Optimizer uses ref join type instead of eq_ref for simple join on 
               strings
   - test case

1 files changed, 1 insertions, 1 deletions

diff --git a/mysql-test/r/merge.result b/mysql-test/r/merge.result
index b8fdd24be74..5196462e97e 100644
--- a/mysql-test/r/merge.result
+++ b/mysql-test/r/merge.result
@@ -626,7 +626,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 EXPLAIN SELECT * FROM t2 WHERE fileset_id = 2
 AND file_code = '0000000115' LIMIT 1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	ref	PRIMARY,files	PRIMARY	35	const,const	1	Using where
+1	SIMPLE	t2	const	PRIMARY,files	PRIMARY	35	const,const	1	
 DROP TABLE t2, t1;
 create table t1 (x int, y int, index xy(x, y));
 create table t2 (x int, y int, index xy(x, y));