The class Window_spec now has pointers to the partition and order lists

of the type SQL_I_List<ORDER> rather then the objects of this type.
It allows to replace easily one instance of such a list for another.
Besides it will facilitate to compare two lists if they originate from the
same window specification.
In fact any direct assignment for objects of the type SQL_I_List<ORDER>
was not valid.

sql/item_windowfunc.cc

@@ -115,7 +115,7 @@ void Item_window_func::split_sum_func(THD *thd, Ref_ptr_array ref_pointer_array,
 
 void Item_window_func::setup_partition_border_check(THD *thd)
 {
-  for (ORDER *curr= window_spec->partition_list.first; curr; curr=curr->next)
+  for (ORDER *curr= window_spec->partition_list->first; curr; curr=curr->next)
   {
     //curr->item_ptr->fix_fields(thd, curr->item);
     Cached_item *tmp= new_Cached_item(thd, curr->item[0], TRUE);  
@@ -128,7 +128,7 @@ void Item_window_func::setup_partition_border_check(THD *thd)
 void Item_sum_rank::setup_window_func(THD *thd, Window_spec *window_spec)
 {
   /* TODO: move this into Item_window_func? */
-  for (ORDER *curr= window_spec->order_list.first; curr; curr=curr->next)
+  for (ORDER *curr= window_spec->order_list->first; curr; curr=curr->next)
   {
     Cached_item *tmp= new_Cached_item(thd, curr->item[0], TRUE);
     orderby_fields.push_back(tmp);
@@ -139,7 +139,7 @@ void Item_sum_rank::setup_window_func(THD *thd, Window_spec *window_spec)
 void Item_sum_dense_rank::setup_window_func(THD *thd, Window_spec *window_spec)
 {
   /* TODO: consider moving this && Item_sum_rank's implementation */
-  for (ORDER *curr= window_spec->order_list.first; curr; curr=curr->next)
+  for (ORDER *curr= window_spec->order_list->first; curr; curr=curr->next)
   {
     Cached_item *tmp= new_Cached_item(thd, curr->item[0], TRUE);
     orderby_fields.push_back(tmp);
@@ -198,7 +198,7 @@ bool Item_sum_percent_rank::add()
 void Item_sum_percent_rank::setup_window_func(THD *thd, Window_spec *window_spec)
 {
   /* TODO: move this into Item_window_func? */
-  for (ORDER *curr= window_spec->order_list.first; curr; curr=curr->next)
+  for (ORDER *curr= window_spec->order_list->first; curr; curr=curr->next)
   {
     Cached_item *tmp= new_Cached_item(thd, curr->item[0], TRUE);
     orderby_fields.push_back(tmp);

sql/sql_parse.cc

@@ -7837,10 +7837,16 @@ bool st_select_lex::add_window_def(THD *thd,
                                    SQL_I_List<ORDER> win_order_list,
                                    Window_frame *win_frame)
 {
+  SQL_I_List<ORDER> *win_part_list_ptr=
+    new (thd->mem_root) SQL_I_List<ORDER> (win_partition_list);
+  SQL_I_List<ORDER> *win_order_list_ptr=
+    new (thd->mem_root) SQL_I_List<ORDER> (win_order_list);
+  if (!(win_part_list_ptr && win_order_list_ptr))
+    return true;
   Window_def *win_def= new (thd->mem_root) Window_def(win_name,
                                                       win_ref,
-                                                      win_partition_list,
-                                                      win_order_list,
+                                                      win_part_list_ptr,
+                                                      win_order_list_ptr,
                                                       win_frame);
   group_list= thd->lex->save_group_list;
   order_list= thd->lex->save_order_list;
@@ -7853,9 +7859,15 @@ bool st_select_lex::add_window_spec(THD *thd,
                                     SQL_I_List<ORDER> win_order_list,
                                     Window_frame *win_frame)
 {
+  SQL_I_List<ORDER> *win_part_list_ptr=
+    new (thd->mem_root) SQL_I_List<ORDER> (win_partition_list);
+  SQL_I_List<ORDER> *win_order_list_ptr=
+    new (thd->mem_root) SQL_I_List<ORDER> (win_order_list);
+  if (!(win_part_list_ptr && win_order_list_ptr))
+    return true;
   Window_spec *win_spec= new (thd->mem_root) Window_spec(win_ref,
-                                                         win_partition_list,
-                                                         win_order_list,
+                                                         win_part_list_ptr,
+                                                         win_order_list_ptr,
                                                          win_frame);
   group_list= thd->lex->save_group_list;
   order_list= thd->lex->save_order_list;

sql/sql_window.cc

@@ -25,13 +25,13 @@ Window_spec::check_window_names(List_iterator_fast<Window_spec> &it)
     if (ref_name &&
         my_strcasecmp(system_charset_info, ref_name, win_spec_name) == 0)
     {
-      if (partition_list.elements)
+      if (partition_list->elements)
       {
         my_error(ER_PARTITION_LIST_IN_REFERENCING_WINDOW_SPEC, MYF(0),
                  ref_name);
         return true;
       }
-      if (win_spec->order_list.elements && order_list.elements)
+      if (win_spec->order_list->elements && order_list->elements)
       {
         my_error(ER_ORDER_LIST_IN_REFERENCING_WINDOW_SPEC, MYF(0), ref_name);
         return true;              
@@ -42,9 +42,9 @@ Window_spec::check_window_names(List_iterator_fast<Window_spec> &it)
         return true;              
       }
       referenced_win_spec= win_spec;
-      if (partition_list.elements == 0)
+      if (partition_list->elements == 0)
         partition_list= win_spec->partition_list;
-      if (order_list.elements == 0)
+      if (order_list->elements == 0)
         order_list= win_spec->order_list;
     }
   }
@@ -109,9 +109,9 @@ setup_windows(THD *thd, Ref_ptr_array ref_pointer_array, TABLE_LIST *tables,
     bool hidden_group_fields;
     if (win_spec->check_window_names(itp) ||
         setup_group(thd, ref_pointer_array, tables, fields, all_fields,
-                    win_spec->partition_list.first, &hidden_group_fields) ||
+                    win_spec->partition_list->first, &hidden_group_fields) ||
         setup_order(thd, ref_pointer_array, tables, fields, all_fields,
-                    win_spec->order_list.first) ||
+                    win_spec->order_list->first) ||
         (win_spec->window_frame && 
          win_spec->window_frame->check_frame_bounds()))
     {
@@ -1205,10 +1205,10 @@ bool compute_window_func_with_frames(Item_window_func *item_win,
   top_bound= get_frame_cursor(window_frame, true);
   bottom_bound= get_frame_cursor(window_frame, false);
     
-  top_bound->init(thd, info, &item_win->window_spec->partition_list,
-                  &item_win->window_spec->order_list);
-  bottom_bound->init(thd, info, &item_win->window_spec->partition_list,
-                     &item_win->window_spec->order_list);
+  top_bound->init(thd, info, item_win->window_spec->partition_list,
+                  item_win->window_spec->order_list);
+  bottom_bound->init(thd, info, item_win->window_spec->partition_list,
+                     item_win->window_spec->order_list);
 
   bool is_error= false;
   longlong rownum= 0;
@@ -1535,20 +1535,20 @@ bool JOIN::process_window_functions(List<Item> *curr_fields_list)
           Connect the two lists for the duration of add_sorting_to_table()
           call.
         */
-        DBUG_ASSERT(spec->partition_list.next[0] == NULL);
-        *(spec->partition_list.next)= spec->order_list.first;
+        DBUG_ASSERT(spec->partition_list->next[0] == NULL);
+        *(spec->partition_list->next)= spec->order_list->first;
 
         /*
            join_tab[top_join_tab_count].table is the temp. table where join
            output was stored.
         */
         add_sorting_to_table(&join_tab[top_join_tab_count],
-                             spec->partition_list.first);
+                             spec->partition_list->first);
         join_tab[top_join_tab_count].used_for_window_func= true;
 
         create_sort_index(this->thd, this, &join_tab[top_join_tab_count]);
         /* Disconnect order_list from partition_list */
-        *(spec->partition_list.next)= NULL;
+        *(spec->partition_list->next)= NULL;
  
        /*
           Go through the sorted array and compute the window function

sql/sql_window.h

@@ -88,17 +88,17 @@ class Window_spec : public Sql_alloc
 
   LEX_STRING *window_ref;
 
-  SQL_I_List<ORDER> partition_list;
+  SQL_I_List<ORDER> *partition_list;
 
-  SQL_I_List<ORDER> order_list;
+  SQL_I_List<ORDER> *order_list;
 
   Window_frame *window_frame;
 
   Window_spec *referenced_win_spec;
 
   Window_spec(LEX_STRING *win_ref, 
-              SQL_I_List<ORDER> part_list,
-              SQL_I_List<ORDER> ord_list,
+              SQL_I_List<ORDER> *part_list,
+              SQL_I_List<ORDER> *ord_list,
               Window_frame *win_frame)
     : window_ref(win_ref), partition_list(part_list), order_list(ord_list),
     window_frame(win_frame), referenced_win_spec(NULL) {}
@@ -107,7 +107,6 @@ class Window_spec : public Sql_alloc
 
   bool check_window_names(List_iterator_fast<Window_spec> &it);
 
-
   char *window_reference() { return window_ref ? window_ref->str : NULL; }
 };
 
@@ -119,8 +118,8 @@ class Window_def : public Window_spec
 
   Window_def(LEX_STRING *win_name,
              LEX_STRING *win_ref, 
-             SQL_I_List<ORDER> part_list,
-             SQL_I_List<ORDER> ord_list,
+             SQL_I_List<ORDER> *part_list,
+             SQL_I_List<ORDER> *ord_list,
              Window_frame *win_frame) 
     : Window_spec(win_ref, part_list, ord_list, win_frame),
       window_name(win_name) {}