Main patch for mdev-9864

sql/sql_class.h

@@ -4196,6 +4196,7 @@ protected:
   /* Something used only by the parser: */
 public:
   select_result(THD *thd_arg): select_result_sink(thd_arg) {}
+  void set_unit(SELECT_LEX_UNIT *unit_arg) { unit= unit_arg; }
   virtual ~select_result() {};
   /**
     Change wrapped select_result.
@@ -4637,6 +4638,7 @@ public:
   }
 };
 
+
 class select_union :public select_result_interceptor
 {
 public:
@@ -4674,6 +4676,25 @@ public:
 };
 
 
+class select_union_recursive :public select_union
+{
+ public:
+  TABLE *incr_table;
+  List<TABLE> rec_tables;
+
+  select_union_recursive(THD *thd_arg):
+    select_union(thd_arg), incr_table(0) {};
+
+  int send_data(List<Item> &items);
+  bool create_result_table(THD *thd, List<Item> *column_types,
+                           bool is_distinct, ulonglong options,
+                           const char *alias, 
+                           bool bit_fields_as_long,
+                           bool create_table,
+                           bool keep_row_order= FALSE);
+  void cleanup();
+};
+
 /**
   UNION result that is passed directly to the receiving select_result
   without filling a temporary table.