many bug fixes

mysql-test/t/subselect.test:
  fixing problems with aliases being forced on derived tables
sql/item_func.cc:
  Fixing a bug that caused MySQL to crash on SELECT ...GROUP BY func(feilds)
sql/item_sum.cc:
  Making us compatible with ISO C++ paragrah 7.1.9.4
sql/item_sum.h:
  Making us compatible with ISO C++ paragrah 7.1.9.4
sql/sql_derived.cc:
  Fixing two more bugs in derived tables.
  
  One in EXPLAIN and another causing wrong result in opt_sum_query()
sql/sql_yacc.yy:
  Making possible INSERT from SELECT list_of_constants

mysql-test/t/subselect.test

@@ -15,12 +15,11 @@ SELECT (SELECT 1), a;
 SELECT 1 as a FROM (SELECT 1) as b HAVING (SELECT a)=1;
 -- error 1054
 SELECT 1 FROM (SELECT (SELECT a) b) c;
-SELECT 1 FROM (SELECT (SELECT a));
-SELECT * FROM (SELECT 1 as id) WHERE id IN (SELECT * FROM (SELECT 1 as id) ORDER BY id LIMIT 1);
+SELECT * FROM (SELECT 1 as id) b WHERE id IN (SELECT * FROM (SELECT 1 as id) c ORDER BY id LIMIT 1);
 -- error 1239
-SELECT * FROM (SELECT 1) WHERE 1 IN (SELECT 1,1);
+SELECT * FROM (SELECT 1)a  WHERE 1 IN (SELECT 1,1);
 SELECT 1 IN (SELECT 1);
-SELECT 1 FROM (SELECT 1 as a) WHERE 1 IN (SELECT (SELECT a));
+SELECT 1 FROM (SELECT 1 as a) b WHERE 1 IN (SELECT (SELECT a));
 drop table if exists t1,t2,t3,t4,t5,t6,t7,t8;
 create table t1 (a int);
 create table t2 (a int, b int);

sql/item_func.cc

@@ -108,8 +108,6 @@ Item_func::fix_fields(THD *thd, TABLE_LIST *tables, Item **ref)
       Set return character set to first argument if we are returning a
       string.
     */
-    if (result_type() == STRING_RESULT)
-      set_charset((*args)->charset());
     for (arg=args, arg_end=args+arg_count; arg != arg_end ; arg++)
     {
       if ((*arg)->check_cols(allowed_arg_cols) ||
@@ -123,6 +121,8 @@ Item_func::fix_fields(THD *thd, TABLE_LIST *tables, Item **ref)
       used_tables_cache|=(*arg)->used_tables();
       const_item_cache&= (*arg)->const_item();
     }
+    if (result_type() == STRING_RESULT)
+      set_charset((*args)->charset());
   }
   fix_length_and_dec();
   fixed= 1;

sql/item_sum.cc

@@ -41,7 +41,7 @@ Item_sum::Item_sum(List<Item> &list)
   list.empty();					// Fields are used
 }
 
-void Item_sum::mark_as_sum_func()
+inline void Item_sum::mark_as_sum_func()
 {
   current_thd->lex.current_select->with_sum_func= with_sum_func= 1;
 }

sql/item_sum.h

@@ -34,6 +34,7 @@ class Item_sum :public Item_result_field
   uint arg_count;
   bool quick_group;			/* If incremental update of fields */
 
+  inline void mark_as_sum_func();
   Item_sum() : arg_count(0),quick_group(1) 
   {
     mark_as_sum_func();
@@ -54,7 +55,6 @@ class Item_sum :public Item_result_field
   }
   Item_sum(List<Item> &list);
   ~Item_sum() { result_field=0; }
-  inline void mark_as_sum_func();
 
   enum Type type() const { return SUM_FUNC_ITEM; }
   virtual enum Sumfunctype sum_func () const=0;

sql/sql_derived.cc

@@ -107,9 +107,12 @@ int mysql_derived(THD *thd, LEX *lex, SELECT_LEX_UNIT *unit, TABLE_LIST *t)
 	  table->derived_select_number= sl->select_number;
 	  table->tmp_table=TMP_TABLE;
 	  if (lex->describe)
+	    tables->table_list->table=tables->table; // to fix a problem in EXPLAIN
+	  else
 	    sl->exclude();
 	  t->db=(char *)"";
 	  t->derived=(SELECT_LEX *)0; // just in case ...
+	  table->file->info(HA_STATUS_VARIABLE);
 	}
       }
       delete derived_result;

sql/sql_yacc.yy

@@ -2977,7 +2977,7 @@ insert_values:
 	    lex->lock_option= (using_update_log) ? TL_READ_NO_INSERT : TL_READ;
 	    mysql_init_select(lex);
 	  }
-	  select_options select_item_list select_from select_lock_type
+	  select_options select_item_list opt_select_from select_lock_type
           union_clause {}
 	;