many bug fixes

mysql-test/r/derived.result:
  test for a bug fix which caused a deadlock !
  Also test for a bug fix with using() on derived tables
mysql-test/r/subselect.result:
  correcting previous changes caused by a bug ..
mysql-test/t/derived.test:
  test for a bug fix which caused a deadlock !
  Also test for a bug fix with using() on derived tables
mysql-test/t/subselect.test:
  corrections of previous changes caused by a bug ..
sql/sql_base.cc:
  A for for a bug which caused a deadlock !
  Also fix for a bug with using() on derived tables
sql/sql_derived.cc:
  code cleanup
sql/sql_lex.cc:
  fix for deadlock

mysql-test/r/derived.result

@@ -64,7 +64,13 @@ a	t
 18	18
 19	19
 20	20
+explain select count(*) from t1 as tt1, (select * from t1) as tt2;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE								Select tables optimized away
 drop table if exists  t1;
 SELECT * FROM (SELECT (SELECT * FROM (SELECT 1 as a) as a )) as b;
 (SELECT * FROM (SELECT 1 as a) as a )
 1
+select * from (select 1 as a) b  left join (select 2 as a) c using(a);
+a	a
+1	NULL

mysql-test/r/subselect.result

@@ -17,14 +17,14 @@ SELECT (SELECT 1),MAX(1) FROM (SELECT 1) as a;
 1	1
 SELECT (SELECT a) as a;
 Reference 'a' not supported (forward reference in item list)
-EXPLAIN SELECT 1,a FROM (SELECT 1 as a) as b  HAVING (SELECT a)=1;
+EXPLAIN SELECT 1 FROM (SELECT 1 as a) as b  HAVING (SELECT a)=1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	<derived2>	system	NULL	NULL	NULL	NULL	1	
 3	DEPENDENT SUBSELECT								No tables used
 2	DERIVED								No tables used
-SELECT 1,a FROM (SELECT 1 as a) as b HAVING (SELECT a)=1;
-1	a
-1	1
+SELECT 1 FROM (SELECT 1 as a) as b HAVING (SELECT a)=1;
+1
+1
 SELECT (SELECT 1), a;
 Unknown column 'a' in 'field list'
 SELECT 1 as a FROM (SELECT 1) as b HAVING (SELECT a)=1;
@@ -387,9 +387,9 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 drop table t1;
 CREATE TABLE t1 (a int(1));
 INSERT INTO t1 VALUES (1);
-SELECT 1,a FROM (SELECT a FROM t1) b HAVING (SELECT b.a)=1;
-1	a
-1	1
+SELECT 1 FROM (SELECT a FROM t1) b HAVING (SELECT b.a)=1;
+1
+1
 drop table t1;
 create table t1 (a int NOT NULL, b int, primary key (a));
 create table t2 (a int NOT NULL, b int, primary key (a));

mysql-test/t/derived.test

@@ -33,5 +33,7 @@ while ($1)
  }
 enable_query_log;
 SELECT * FROM (SELECT * FROM t1) as b ORDER BY a  ASC LIMIT 0,20;
+explain select count(*) from t1 as tt1, (select * from t1) as tt2;
 drop table if exists  t1;
 SELECT * FROM (SELECT (SELECT * FROM (SELECT 1 as a) as a )) as b;
+select * from (select 1 as a) b  left join (select 2 as a) c using(a);

mysql-test/t/subselect.test

@@ -8,8 +8,8 @@ SELECT (SELECT 1 FROM (SELECT 1) as b HAVING b=1) as a,(SELECT 1 FROM (SELECT 1)
 SELECT (SELECT 1),MAX(1) FROM (SELECT 1) as a;
 -- error 1245
 SELECT (SELECT a) as a;
-EXPLAIN SELECT 1,a FROM (SELECT 1 as a) as b  HAVING (SELECT a)=1;
-SELECT 1,a FROM (SELECT 1 as a) as b HAVING (SELECT a)=1;
+EXPLAIN SELECT 1 FROM (SELECT 1 as a) as b  HAVING (SELECT a)=1;
+SELECT 1 FROM (SELECT 1 as a) as b HAVING (SELECT a)=1;
 -- error 1054
 SELECT (SELECT 1), a;
 SELECT 1 as a FROM (SELECT 1) as b HAVING (SELECT a)=1;
@@ -230,7 +230,7 @@ drop table t1;
 
 CREATE TABLE t1 (a int(1));
 INSERT INTO t1 VALUES (1);
-SELECT 1,a FROM (SELECT a FROM t1) b HAVING (SELECT b.a)=1;
+SELECT 1 FROM (SELECT a FROM t1) b HAVING (SELECT b.a)=1;
 drop table t1;
 
 #update with subselects

sql/sql_base.cc

@@ -1894,13 +1894,13 @@ find_field_in_tables(THD *thd, Item_ident *item, TABLE_LIST *tables,
   const char *name=item->field_name;
   uint length=(uint) strlen(name);
 
-  if (table_name)
+  if (table_name && table_name[0])
   {						/* Qualified field */
     bool found_table=0;
     for (; tables ; tables=tables->next)
     {
       if (!strcmp(tables->alias,table_name) &&
-	  (!db || !strcmp(db,tables->db)))
+	  (!db || !tables->db ||  !tables->db[0] || !strcmp(db,tables->db)))
       {
 	found_table=1;
 	Field *find=find_field_in_table(thd,tables->table,name,length,

sql/sql_derived.cc

@@ -106,9 +106,9 @@ int mysql_derived(THD *thd, LEX *lex, SELECT_LEX_UNIT *unit, TABLE_LIST *t)
 	  t->table=table;
 	  table->derived_select_number= sl->select_number;
 	  table->tmp_table=TMP_TABLE;
-	  if (!lex->describe)
+	  if (lex->describe)
 	    sl->exclude();
-	  t->db=(tables && tables->db) ? tables->db : (char *)"";
+	  t->db=(char *)"";
 	  t->derived=(SELECT_LEX *)0; // just in case ...
 	}
       }

sql/sql_lex.cc

@@ -1173,6 +1173,8 @@ bool st_select_lex_unit::create_total_list_n_last_return(THD *thd, st_lex *lex,
       net_printf(thd,ER_WRONG_USAGE,"UNION","ORDER BY");
       return 1;
     }
+    if (sl->linkage == DERIVED_TABLE_TYPE)
+      continue;
     for (SELECT_LEX_UNIT *inner=  sl->first_inner_unit();
 	 inner;
 	 inner= inner->next_unit())