Bugs, found by valgrind

Author: montywi

sql/item_cmpfunc.cc

@@ -6278,8 +6278,8 @@ longlong Item_equal::val_int()
  while ((item= it++))
  {
  Field *field= it.get_curr_field();
- /* Skip fields of non-const tables. They haven't been read yet */
- if (field->table->const_table)
+ /* Skip fields of tables that has not been read yet */
+ if (!field->table->status || (field->table->status & STATUS_NULL_ROW))
  {
  if (eval_item->cmp(item) || (null_value= item->null_value))
  return 0;

sql/sql_select.cc

@@ -24183,6 +24183,8 @@ int JOIN::save_explain_data_intern(Explain_query *output, bool need_tmp_table,
 
  explain->select_id= join->select_lex->select_number;
  explain->select_type= join->select_lex->type;
+ explain->using_temporary= need_tmp;
+ explain->using_filesort= need_order;
  /* Setting explain->message means that all other members are invalid */
  explain->message= message;