fixed unlocking tables during subquery execution (BUG#2048)

mysql-test/r/subselect_innodb.result:
  bug 2048 test
mysql-test/t/subselect_innodb.test:
  bug 2048 test
sql/item_subselect.cc:
  do not unlock tables for subqueries
sql/sql_derived.cc:
  derived table tables can be unlocked
sql/sql_lex.h:
  new interface to pass additional options
sql/sql_union.cc:
  new interface to pass additional options
  do not unlock tables for UNION

mysql-test/r/subselect_innodb.result

@@ -63,3 +63,23 @@ processor_id	(SELECT y.yod_id FROM t1 p2, t2 y WHERE p2.processor_id = p1.proces
 2	1
 3	1
 drop table t1,t2,t3;
+CREATE TABLE t1 (
+id int(11) NOT NULL default '0',
+b int(11) default NULL,
+c char(3) default NULL,
+PRIMARY KEY  (id),
+KEY t2i1 (b)
+) TYPE=innodb DEFAULT CHARSET=latin1;
+INSERT INTO t1 VALUES (0,0,'GPL'),(1,0,'GPL'),(2,1,'GPL'),(3,2,'GPL');
+CREATE TABLE t2 (
+id int(11) NOT NULL default '0',
+b int(11) default NULL,
+c char(3) default NULL,
+PRIMARY KEY  (id),
+KEY t2i (b)
+) TYPE=innodb DEFAULT CHARSET=latin1;
+INSERT INTO t2 VALUES (0,0,'GPL'),(1,0,'GPL'),(2,1,'GPL'),(3,2,'GPL');
+select (select max(id) from t2 where b=1 group by b) as x,b from t1 where b=1;
+x	b
+2	1
+drop table t1,t2;

mysql-test/t/subselect_innodb.test

@@ -68,3 +68,25 @@ INSERT INTO t3 VALUES (1,1),(2,2),(3,3);
 INSERT INTO t2 VALUES (1,1),(2,2),(3,3);
 SELECT distinct p1.processor_id, (SELECT y.yod_id FROM t1 p2, t2 y WHERE p2.processor_id = p1.processor_id and p2.processor_id = y.processor_id) FROM t1 p1;
 drop table t1,t2,t3;
+
+#
+# innodb locking
+#
+CREATE TABLE t1 (
+  id int(11) NOT NULL default '0',
+  b int(11) default NULL,
+  c char(3) default NULL,
+  PRIMARY KEY  (id),
+  KEY t2i1 (b)
+) TYPE=innodb DEFAULT CHARSET=latin1;
+INSERT INTO t1 VALUES (0,0,'GPL'),(1,0,'GPL'),(2,1,'GPL'),(3,2,'GPL');
+CREATE TABLE t2 (
+  id int(11) NOT NULL default '0',
+  b int(11) default NULL,
+  c char(3) default NULL,
+  PRIMARY KEY  (id),
+  KEY t2i (b)
+) TYPE=innodb DEFAULT CHARSET=latin1;
+INSERT INTO t2 VALUES (0,0,'GPL'),(1,0,'GPL'),(2,1,'GPL'),(3,2,'GPL');
+select (select max(id) from t2 where b=1 group by b) as x,b from t1 where b=1;
+drop table t1,t2;

sql/item_subselect.cc

@@ -906,7 +906,8 @@ int subselect_single_select_engine::prepare()
 {
   if (prepared)
     return 0;
-  join= new JOIN(thd, select_lex->item_list, select_lex->options, result);
+  join= new JOIN(thd, select_lex->item_list,
+		 select_lex->options | SELECT_NO_UNLOCK, result);
   if (!join || !result)
   {
     thd->fatal_error();				//out of memory
@@ -933,7 +934,7 @@ int subselect_single_select_engine::prepare()
 
 int subselect_union_engine::prepare()
 {
-  return unit->prepare(thd, result);
+  return unit->prepare(thd, result, SELECT_NO_UNLOCK);
 }
 
 int subselect_uniquesubquery_engine::prepare()

sql/sql_derived.cc

@@ -114,7 +114,7 @@ int mysql_derived(THD *thd, LEX *lex, SELECT_LEX_UNIT *unit,
       DBUG_RETURN(1); // out of memory
 
     // st_select_lex_unit::prepare correctly work for single select
-    if ((res= unit->prepare(thd, derived_result)))
+    if ((res= unit->prepare(thd, derived_result, 0)))
       goto exit;
 
     /* 

sql/sql_lex.h

@@ -351,7 +351,7 @@ public:
   void exclude_tree();
 
   /* UNION methods */
-  int prepare(THD *thd, select_result *result);
+  int prepare(THD *thd, select_result *result, ulong additional_options);
   int exec();
   int cleanup();
 

sql/sql_union.cc

@@ -29,7 +29,7 @@ int mysql_union(THD *thd, LEX *lex, select_result *result,
 {
   DBUG_ENTER("mysql_union");
   int res= 0;
-  if (!(res= unit->prepare(thd, result)))
+  if (!(res= unit->prepare(thd, result, SELECT_NO_UNLOCK)))
     res= unit->exec();
   res|= unit->cleanup();
   DBUG_RETURN(res);
@@ -106,7 +106,8 @@ bool select_union::flush()
 }
 
 
-int st_select_lex_unit::prepare(THD *thd_arg, select_result *sel_result)
+int st_select_lex_unit::prepare(THD *thd_arg, select_result *sel_result,
+				ulong additional_options)
 {
   SELECT_LEX *lex_select_save= thd_arg->lex.current_select;
   SELECT_LEX *sl, *first_select;
@@ -146,7 +147,7 @@ int st_select_lex_unit::prepare(THD *thd_arg, select_result *sel_result)
   for (;sl; sl= sl->next_select())
   {
     JOIN *join= new JOIN(thd_arg, sl->item_list, 
-			 sl->options | thd_arg->options | SELECT_NO_UNLOCK,
+			 sl->options | thd_arg->options | additional_options,
 			 tmp_result);
     thd_arg->lex.current_select= sl;
     offset_limit_cnt= sl->offset_limit;