Merge olga.mysql.com:/home/igor/mysql-5.0-opt

into  olga.mysql.com:/home/igor/dev-opt/mysql-5.0-opt-bug24035

mysql-test/r/update.result

@@ -377,3 +377,60 @@ create table t1(f1 int, `*f2` int);
 insert into t1 values (1,1);
 update t1 set `*f2`=1;
 drop table t1;
+CREATE TABLE t1 (
+request_id int unsigned NOT NULL auto_increment,
+user_id varchar(12) default NULL,
+time_stamp datetime NOT NULL default '0000-00-00 00:00:00',
+ip_address varchar(15) default NULL,
+PRIMARY KEY (request_id),
+KEY user_id_2 (user_id,time_stamp)
+);
+INSERT INTO t1 (user_id) VALUES ('user1');
+INSERT INTO t1(user_id) SELECT user_id FROM t1;
+INSERT INTO t1(user_id) SELECT user_id FROM t1;
+INSERT INTO t1(user_id) SELECT user_id FROM t1;
+INSERT INTO t1(user_id) SELECT user_id FROM t1;
+INSERT INTO t1(user_id) SELECT user_id FROM t1;
+INSERT INTO t1(user_id) SELECT user_id FROM t1;
+INSERT INTO t1(user_id) SELECT user_id FROM t1;
+INSERT INTO t1(user_id) SELECT user_id FROM t1;
+flush status;
+SELECT user_id FROM t1 WHERE request_id=9999999999999;
+user_id
+show status like '%Handler_read%';
+Variable_name	Value
+Handler_read_first	0
+Handler_read_key	1
+Handler_read_next	0
+Handler_read_prev	0
+Handler_read_rnd	0
+Handler_read_rnd_next	0
+SELECT user_id FROM t1 WHERE request_id=999999999999999999999999999999;
+user_id
+show status like '%Handler_read%';
+Variable_name	Value
+Handler_read_first	0
+Handler_read_key	2
+Handler_read_next	0
+Handler_read_prev	0
+Handler_read_rnd	0
+Handler_read_rnd_next	7
+UPDATE t1 SET user_id=null WHERE request_id=9999999999999;
+show status like '%Handler_read%';
+Variable_name	Value
+Handler_read_first	0
+Handler_read_key	3
+Handler_read_next	0
+Handler_read_prev	0
+Handler_read_rnd	0
+Handler_read_rnd_next	14
+UPDATE t1 SET user_id=null WHERE request_id=999999999999999999999999999999;
+show status like '%Handler_read%';
+Variable_name	Value
+Handler_read_first	0
+Handler_read_key	3
+Handler_read_next	0
+Handler_read_prev	0
+Handler_read_rnd	0
+Handler_read_rnd_next	21
+DROP TABLE t1;

mysql-test/t/update.test

@@ -307,3 +307,38 @@ insert into t1 values (1,1);
 update t1 set `*f2`=1;
 drop table t1;
 # End of 4.1 tests
+
+#
+# Bug #24035: performance degradation with condition int_field=big_decimal
+#
+
+CREATE TABLE t1 (
+  request_id int unsigned NOT NULL auto_increment,
+  user_id varchar(12) default NULL,
+  time_stamp datetime NOT NULL default '0000-00-00 00:00:00',
+  ip_address varchar(15) default NULL,
+  PRIMARY KEY (request_id),
+  KEY user_id_2 (user_id,time_stamp)
+);
+
+INSERT INTO t1 (user_id) VALUES ('user1');
+INSERT INTO t1(user_id) SELECT user_id FROM t1;
+INSERT INTO t1(user_id) SELECT user_id FROM t1;
+INSERT INTO t1(user_id) SELECT user_id FROM t1;
+INSERT INTO t1(user_id) SELECT user_id FROM t1;
+INSERT INTO t1(user_id) SELECT user_id FROM t1;
+INSERT INTO t1(user_id) SELECT user_id FROM t1;
+INSERT INTO t1(user_id) SELECT user_id FROM t1;
+INSERT INTO t1(user_id) SELECT user_id FROM t1;
+
+flush status;
+SELECT user_id FROM t1 WHERE request_id=9999999999999; 
+show status like '%Handler_read%';
+SELECT user_id FROM t1 WHERE request_id=999999999999999999999999999999; 
+show status like '%Handler_read%';
+UPDATE t1 SET user_id=null WHERE request_id=9999999999999;
+show status like '%Handler_read%';
+UPDATE t1 SET user_id=null WHERE request_id=999999999999999999999999999999;
+show status like '%Handler_read%';
+
+DROP TABLE t1;

sql/opt_range.cc

@@ -4296,7 +4296,22 @@ get_mm_leaf(PARAM *param, COND *conf_func, Field *field, KEY_PART *key_part,
   err= value->save_in_field_no_warnings(field, 1);
   if (err > 0 && field->cmp_type() != value->result_type())
   {
-    tree= 0;
+    if ((type == Item_func::EQ_FUNC || type == Item_func::EQUAL_FUNC) &&
+	value->result_type() == item_cmp_type(field->result_type(),
+                                              value->result_type()))
+
+    {
+      tree= new (alloc) SEL_ARG(field, 0, 0);
+      tree->type= SEL_ARG::IMPOSSIBLE;
+    }
+    else
+    {
+      /*
+        TODO: We should return trees of the type SEL_ARG::IMPOSSIBLE
+        for the cases like int_field > 999999999999999999999999 as well.
+      */
+      tree= 0;
+    }
     goto end;
   } 
   if (err < 0)