Fixed bug mdev-4952

When in function remove_eq_conds() a sub-formula of the processed condition
is replaced for another formula we should ensure that in the resulting
formula AND/OR levels must alternate.

mysql-test/r/join_outer.result

@@ -1848,4 +1848,18 @@ INSERT INTO t2 VALUES (3,'2000-03-06'), (4,'2007-09-25');
 SELECT * FROM t1 LEFT JOIN t2 ON i1 = i2 WHERE d1 IS NULL AND d2 IS NULL;
 i1	d1	i2	d2
 DROP TABLE t1,t2;
+#
+# Bug mdev-4952: LEFT JOIN with disjunctive 
+#                <non-nullable datetime field> IS NULL in WHERE 
+#                causes an assert failure  
+#
+CREATE TABLE t1 (a1 int, b1 int NOT NULL) ENGINE=MyISAM;
+INSERT INTO t1 VALUES (1, 10), (2, 11);
+CREATE TABLE t2 (dt datetime NOT NULL, a2 int, b2 int) ENGINE=MyISAM;
+INSERT INTO t2 VALUES
+('2006-10-08 09:34:54', 1, 100), ('2001-01-19 01:04:43', 2, 200);
+SELECT * FROM t1 LEFT JOIN t2 ON a1 = a2
+WHERE ( dt IS NULL OR FALSE ) AND b2 IS NULL;
+a1	b1	dt	a2	b2
+DROP TABLE t1,t2;
 SET optimizer_switch=@save_optimizer_switch;

mysql-test/r/join_outer_jcl6.result

@@ -1859,6 +1859,20 @@ INSERT INTO t2 VALUES (3,'2000-03-06'), (4,'2007-09-25');
 SELECT * FROM t1 LEFT JOIN t2 ON i1 = i2 WHERE d1 IS NULL AND d2 IS NULL;
 i1	d1	i2	d2
 DROP TABLE t1,t2;
+#
+# Bug mdev-4952: LEFT JOIN with disjunctive 
+#                <non-nullable datetime field> IS NULL in WHERE 
+#                causes an assert failure  
+#
+CREATE TABLE t1 (a1 int, b1 int NOT NULL) ENGINE=MyISAM;
+INSERT INTO t1 VALUES (1, 10), (2, 11);
+CREATE TABLE t2 (dt datetime NOT NULL, a2 int, b2 int) ENGINE=MyISAM;
+INSERT INTO t2 VALUES
+('2006-10-08 09:34:54', 1, 100), ('2001-01-19 01:04:43', 2, 200);
+SELECT * FROM t1 LEFT JOIN t2 ON a1 = a2
+WHERE ( dt IS NULL OR FALSE ) AND b2 IS NULL;
+a1	b1	dt	a2	b2
+DROP TABLE t1,t2;
 SET optimizer_switch=@save_optimizer_switch;
 set join_cache_level=default;
 show variables like 'join_cache_level';

mysql-test/t/join_outer.test

@@ -1392,4 +1392,22 @@ SELECT * FROM t1 LEFT JOIN t2 ON i1 = i2 WHERE d1 IS NULL AND d2 IS NULL;
 
 DROP TABLE t1,t2;
 
+--echo #
+--echo # Bug mdev-4952: LEFT JOIN with disjunctive 
+--echo #                <non-nullable datetime field> IS NULL in WHERE 
+--echo #                causes an assert failure  
+--echo #
+
+CREATE TABLE t1 (a1 int, b1 int NOT NULL) ENGINE=MyISAM;
+INSERT INTO t1 VALUES (1, 10), (2, 11);
+
+CREATE TABLE t2 (dt datetime NOT NULL, a2 int, b2 int) ENGINE=MyISAM;
+INSERT INTO t2 VALUES
+('2006-10-08 09:34:54', 1, 100), ('2001-01-19 01:04:43', 2, 200);
+
+SELECT * FROM t1 LEFT JOIN t2 ON a1 = a2
+  WHERE ( dt IS NULL OR FALSE ) AND b2 IS NULL;
+
+DROP TABLE t1,t2;
+
 SET optimizer_switch=@save_optimizer_switch;

sql/sql_select.cc

@@ -13407,7 +13407,20 @@ remove_eq_conds(THD *thd, COND *cond, Item::cond_result *cond_value)
         }
         else
 	{
-          li.replace(new_item);
+          if (new_item->type() == Item::COND_ITEM &&
+              ((Item_cond*) new_item)->functype() == 
+              ((Item_cond*) cond)->functype())
+	  {
+	    List<Item> *new_item_arg_list=
+              ((Item_cond *) new_item)->argument_list();
+            uint cnt= new_item_arg_list->elements;
+            li.replace(*new_item_arg_list);
+            /* Make iterator li ignore new items */
+            for (cnt--; cnt; cnt--)
+              li++;
+          }
+          else
+            li.replace(new_item);
           should_fix_fields= 1;
         } 
       }