Make semi-joins work with outer joins:

- evaluate_null_complemented_join_record() should perform FirstMatch checks.

mysql-test/r/subselect_sj.result

@@ -1414,6 +1414,17 @@ select * from t0 where a in (select t1.a from t1 left join t2 on t1.a=t2.a);
 a
 1
 2
+set optimizer_switch='firstmatch=on';
+explain 
+select * from t0 where a in (select t1.a from t1 left join t2 on t1.a=t2.a);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	PRIMARY	t0	ALL	NULL	NULL	NULL	NULL	2	
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	4	Using where
+1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	1	Using where; FirstMatch(t0)
+select * from t0 where a in (select t1.a from t1 left join t2 on t1.a=t2.a);
+a
+1
+2
 set @@join_cache_level=@tmp_jcl_20110622;
 set @@optimizer_switch=@tmp_20110622;
 drop table t0, t1, t2;

mysql-test/r/subselect_sj_jcl6.result

@@ -1422,6 +1422,17 @@ select * from t0 where a in (select t1.a from t1 left join t2 on t1.a=t2.a);
 a
 1
 2
+set optimizer_switch='firstmatch=on';
+explain 
+select * from t0 where a in (select t1.a from t1 left join t2 on t1.a=t2.a);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	PRIMARY	t0	ALL	NULL	NULL	NULL	NULL	2	
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	4	Using where
+1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	1	Using where; FirstMatch(t0)
+select * from t0 where a in (select t1.a from t1 left join t2 on t1.a=t2.a);
+a
+1
+2
 set @@join_cache_level=@tmp_jcl_20110622;
 set @@optimizer_switch=@tmp_20110622;
 drop table t0, t1, t2;

mysql-test/t/subselect_sj.test

@@ -1291,6 +1291,12 @@ explain
 select * from t0 where a in (select t1.a from t1 left join t2 on t1.a=t2.a);
 select * from t0 where a in (select t1.a from t1 left join t2 on t1.a=t2.a);
 
+
+set optimizer_switch='firstmatch=on';
+explain 
+select * from t0 where a in (select t1.a from t1 left join t2 on t1.a=t2.a);
+select * from t0 where a in (select t1.a from t1 left join t2 on t1.a=t2.a);
+
 set @@join_cache_level=@tmp_jcl_20110622;
 set @@optimizer_switch=@tmp_20110622;
 

sql/sql_select.cc

@@ -15220,6 +15220,15 @@ evaluate_null_complemented_join_record(JOIN *join, JOIN_TAB *join_tab)
     else if (res == 1)
       return NESTED_LOOP_OK;
   }
+  else if (join_tab->do_firstmatch)
+  {
+    /* 
+      We should return to the join_tab->do_firstmatch after we have 
+      enumerated all the suffixes for current prefix row combination
+    */
+    if (join_tab->do_firstmatch < join->return_tab)
+      join->return_tab= join_tab->do_firstmatch;
+  }
 
   /*
     Send the row complemented by nulls to be joined with the