Fixed an unlikely optimizer bug that casued a core dump in pt_range.cc::sel_cmp()

mysql-test/r/join.result:
  Test of range optimizer bug
mysql-test/t/join.test:
  Test of range optimizer bug
sql/sql_rename.cc:
  Added missing DEBUG_PRINT()

2 files changed, 28 insertions, 0 deletions

diff --git a/mysql-test/r/join.result b/mysql-test/r/join.result
index 39331fc68e4..0c575d7505e 100644
--- a/mysql-test/r/join.result
+++ b/mysql-test/r/join.result
@@ -37,3 +37,7 @@ COUNT(t1.Title)
 t1_id	t2_id	type	cost_unit	min_value	max_value	t3_id	item_id	id	name
 22	1	Percent	Cost	100	-1	6	291	1	s1
 23	1	Percent	Cost	100	-1	21	291	1	s1
+rate_code	base_rate
+cust	20
+rate_code	base_rate
+cust	20
diff --git a/mysql-test/t/join.test b/mysql-test/t/join.test
index d31db5c4837..6a022e690f2 100644
--- a/mysql-test/t/join.test
+++ b/mysql-test/t/join.test
@@ -219,3 +219,27 @@ CREATE TABLE t2 (
 INSERT INTO t2 VALUES (1,'s1'),(2,'s2'),(3,'s3'),(4,'s4'),(5,'s5');
 select t1.*, t2.*  from t1, t2 where t2.id=t1.t2_id limit 2;
 drop table t1,t2;
+
+#
+# Bug in range optimiser with MAYBE_KEY
+#
+
+CREATE TABLE t1 (
+  siteid varchar(25) NOT NULL default '',
+  emp_id varchar(30) NOT NULL default '',
+  rate_code varchar(10) default NULL,
+  UNIQUE KEY site_emp (siteid,emp_id),
+  KEY siteid (siteid)
+) TYPE=MyISAM;
+INSERT INTO t1 VALUES ('rivercats','psmith','cust'), ('rivercats','KWalker','cust');
+CREATE TABLE t2 (
+  siteid varchar(25) NOT NULL default '',
+  rate_code varchar(10) NOT NULL default '',
+  base_rate float NOT NULL default '0',
+  PRIMARY KEY  (siteid,rate_code),
+  FULLTEXT KEY rate_code (rate_code)
+) TYPE=MyISAM;
+INSERT INTO t2 VALUES ('rivercats','cust',20);
+SELECT emp.rate_code, lr.base_rate FROM t1 AS emp LEFT JOIN t2 AS lr USING (siteid, rate_code) WHERE emp.emp_id = 'psmith' AND lr.siteid = 'rivercats';
+SELECT emp.rate_code, lr.base_rate FROM t1 AS emp LEFT JOIN t2 AS lr USING (siteid, rate_code) WHERE lr.siteid = 'rivercats' AND emp.emp_id = 'psmith';
+drop table t1,t2;