outer join, impossible on condition, where, and usable key for range

bug#926

mysql-test/r/select.result

@@ -3508,3 +3508,23 @@ aa	id	t2_id	id
 5	8303	2520	2520
 6	8304	2521	2521
 drop table t1,t2;
+create table t1 (id1 int NOT NULL);
+create table t2 (id2 int NOT NULL);
+create table t3 (id3 int NOT NULL);
+create table t4 (id4 int NOT NULL, id44 int NOT NULL, KEY (id4));
+insert into t1 values (1);
+insert into t1 values (2);
+insert into t2 values (1);
+insert into t4 values (1,1);
+explain select * from t1 left join t2 on id1 = id2 left join t3 on id1 = id3
+left join t4 on id3 = id4 where id2 = 1 or id4 = 1;
+table	type	possible_keys	key	key_len	ref	rows	Extra
+t3	system	NULL	NULL	NULL	NULL	0	const row not found
+t1	ALL	NULL	NULL	NULL	NULL	2	
+t2	ALL	NULL	NULL	NULL	NULL	1	
+t4	ALL	id4	NULL	NULL	NULL	1	Using where
+select * from t1 left join t2 on id1 = id2 left join t3 on id1 = id3
+left join t4 on id3 = id4 where id2 = 1 or id4 = 1;
+id1	id2	id3	id4	id44
+1	1	NULL	NULL	NULL
+drop table t1,t2,t3,t4;

mysql-test/t/select.test

@@ -1832,3 +1832,23 @@ INSERT INTO t2 VALUES (2517), (2518), (2519), (2520), (2521), (2522);
 select * from t1, t2 WHERE t1.t2_id = t2.id and t1.t2_id > 0   order by t1.id   LIMIT 0, 5;
 drop table t1,t2;
 
+#
+# outer join, impossible on condition, where, and usable key for range
+#
+create table t1 (id1 int NOT NULL);
+create table t2 (id2 int NOT NULL);
+create table t3 (id3 int NOT NULL);
+create table t4 (id4 int NOT NULL, id44 int NOT NULL, KEY (id4));
+
+insert into t1 values (1);
+insert into t1 values (2);
+insert into t2 values (1);
+insert into t4 values (1,1);
+
+explain select * from t1 left join t2 on id1 = id2 left join t3 on id1 = id3
+left join t4 on id3 = id4 where id2 = 1 or id4 = 1;
+select * from t1 left join t2 on id1 = id2 left join t3 on id1 = id3
+left join t4 on id3 = id4 where id2 = 1 or id4 = 1;
+
+drop table t1,t2,t3,t4;
+

sql/sql_select.cc

@@ -2641,9 +2641,6 @@ make_join_select(JOIN *join,SQL_SELECT *select,COND *cond)
 	       join->thd->select_limit < join->best_positions[i].records_read &&
 	       !(join->select_options & OPTION_FOUND_ROWS)))
 	  {
-	    /* Join with outer join condition */
-	    COND *orig_cond=sel->cond;
-	    sel->cond=and_conds(sel->cond,tab->on_expr);
 	    if (sel->test_quick_select(tab->keys,
 				       used_tables & ~ current_map,
 				       (join->select_options &
@@ -2651,7 +2648,6 @@ make_join_select(JOIN *join,SQL_SELECT *select,COND *cond)
 					HA_POS_ERROR :
 					join->thd->select_limit)) < 0)
 	      DBUG_RETURN(1);				// Impossible range
-	    sel->cond=orig_cond;
 	    /* Fix for EXPLAIN */
 	    if (sel->quick)
 	      join->best_positions[i].records_read= sel->quick->records;