subselect transformation moved in after-fix_field place

removed "of is null" if it is possible
  (this cset should be SCRUM related, but not approved as scrum task yet)


mysql-test/r/subselect.result:
  new subselect test result (new place of error detecting & and more subselect reducing)
sql/item.cc:
  layout fix
sql/item.h:
  unneed ';'
  fixed print pethod
sql/item_cmpfunc.cc:
  new method to support transformation after fix_fields
sql/item_cmpfunc.h:
  new method to support transformation after fix_fields
  fixed Item printing
sql/item_subselect.cc:
  new transformation
sql/item_subselect.h:
  new transformation
sql/sql_derived.cc:
  'table' & 'table_list' now is not union
sql/sql_lex.cc:
  'table' & 'table_list' now is not union to support reinit only shared tables (but all)
sql/sql_lex.h:
  mark fake st_select_lex
sql/sql_olap.cc:
  fixed table assignment
  TODO added
sql/sql_select.cc:
  'table' & 'table_list' now is not union
  transforming subselect
sql/sql_union.cc:
  prepare make on fix_fields
sql/sql_yacc.yy:
  fixed layout
sql/table.h:
  'table & 'table_list' now is different fields

1 files changed, 19 insertions, 1 deletions

diff --git a/sql/item.h b/sql/item.h
index 3a5a06c3af3..7b758f76fc8 100644
--- a/sql/item.h
+++ b/sql/item.h
@@ -100,7 +100,7 @@ public:
   virtual bool get_time(TIME *ltime);
   virtual bool get_date_result(TIME *ltime,bool fuzzydate)
   { return get_date(ltime,fuzzydate); }
-  virtual bool is_null() { return 0; };
+  virtual bool is_null() { return 0; }
   virtual void top_level_item() {}
   virtual void set_result_field(Field *field) {}
   virtual bool is_result_field() { return 0; }
@@ -560,6 +560,15 @@ public:
   longlong val_int();
   String* val_str(String* s);
   bool get_date(TIME *ltime, bool fuzzydate);
+  void print(String *str)
+  {
+    str->append("ref_null_helper(");
+    if (ref && *ref)
+      (*ref)->print(str);
+    else
+      str->append('?');
+    str->append(')');
+  }
 };
 
 
@@ -605,6 +614,15 @@ public:
   {}
   bool fix_fields(THD *, struct st_table_list *, Item ** ref);
   Item **storage() {return &item;}
+  void print(String *str)
+  {
+    str->append("ref_null_helper('");
+    if (item)
+      item->print(str);
+    else
+      str->append('?');
+    str->append(')');
+  }
 };
 
 /*