MDEV-34348: sql/bounded_queue.h Remove compare_function

Remove compare_function from bounded_queue altogether
because it is never actually instantiated with a value.

sql/bounded_queue.h

@@ -62,16 +62,6 @@ class Bounded_queue
                                     Element_type *from,
                                     bool packing_keys);
 
-  /**
-     Function for comparing two keys.
-     @param  n Pointer to number of bytes to compare.
-     @param  a First key.
-     @param  b Second key.
-     @retval -1, 0, or 1 depending on whether the left argument is 
-             less than, equal to, or greater than the right argument.
-   */
-  typedef int (*compare_function)(size_t *n, Key_type **a, Key_type **b);
-
   /**
     Initialize the queue.
 
@@ -93,7 +83,7 @@ class Bounded_queue
     We do *not* take ownership of any of the input pointer arguments.
    */
   int init(ha_rows max_elements, bool max_at_top,
-           compare_function compare, size_t compare_length,
+           size_t compare_length,
            keymaker_function keymaker, Sort_param *sort_param,
            Key_type **sort_keys);
 
@@ -148,7 +138,6 @@ class Bounded_queue
 template<typename Element_type, typename Key_type>
 int Bounded_queue<Element_type, Key_type>::init(ha_rows max_elements,
                                                 bool max_at_top,
-                                                compare_function compare,
                                                 size_t compare_length,
                                                 keymaker_function keymaker,
                                                 Sort_param *sort_param,
@@ -163,13 +152,10 @@ int Bounded_queue<Element_type, Key_type>::init(ha_rows max_elements,
   // init_queue() takes an uint, and also does (max_elements + 1)
   if (max_elements >= (UINT_MAX - 1))
     return 1;
-  if (compare == NULL)
-    compare=
-      reinterpret_cast<compare_function>(get_ptr_compare(compare_length));
   // We allocate space for one extra element, for replace when queue is full.
   return init_queue(&m_queue, (uint) max_elements + 1,
                     0, max_at_top,
-                    reinterpret_cast<queue_compare>(compare),
+                    get_ptr_compare(compare_length),
                     &m_compare_length, 0, 0);
 }
 

sql/filesort.cc

@@ -283,7 +283,6 @@ SORT_INFO *filesort(THD *thd, TABLE *table, Filesort *filesort,
     sort->init_record_pointers();
     if (pq.init(param.max_rows,
                 true,                           // max_at_top
-                NULL,                           // compare_function
                 compare_length,
                 &make_sortkey, &param, sort->get_sort_keys()))
     {