BUG#18160 - Memory-/HEAP Table endless growing indexes

Updating data in HEAP table with BTREE index results in wrong index_length
counter value, which keeps growing after each update.

When inserting new record into tree counter is incremented by:
sizeof(TREE_ELEMENT) + key_size + tree->size_of_element
But when deleting element from tree it doesn't decrement counter by key_size:
sizeof(TREE_ELEMENT) + tree->size_of_element

This fix makes accurate allocated memory counter for tree. That is
decrease counter by key_size when deleting tree element.


heap/hp_delete.c:
  Added size of the key to tree_delete() for accurate allocated memory counter.
include/my_tree.h:
  Added size of the key to tree_delete() for accurate allocated memory counter.
myisam/myisamlog.c:
  Added size of the key to tree_delete() for accurate allocated memory counter.
mysql-test/r/heap_btree.result:
  Testcase for BUG#18160.
mysql-test/t/heap_btree.test:
  Testcase for BUG#18160.
mysys/tree.c:
  Added size of the key to tree_delete() for accurate allocated memory counter.
  Note that this size is optional. If one doesn't need precise counter it is safe
  to pass 0 as key_size.

1 files changed, 2 insertions, 3 deletions

diff --git a/mysys/tree.c b/mysys/tree.c
index 1780913961e..0c9c04919b0 100644
--- a/mysys/tree.c
+++ b/mysys/tree.c
@@ -271,7 +271,7 @@ TREE_ELEMENT *tree_insert(TREE *tree, void *key, uint key_size,
   return element;
 }
 
-int tree_delete(TREE *tree, void *key, void *custom_arg)
+int tree_delete(TREE *tree, void *key, uint key_size, void *custom_arg)
 {
   int cmp,remove_colour;
   TREE_ELEMENT *element,***parent, ***org_parent, *nod;
@@ -326,8 +326,7 @@ int tree_delete(TREE *tree, void *key, void *custom_arg)
     rb_delete_fixup(tree,parent);
   if (tree->free)
     (*tree->free)(ELEMENT_KEY(tree,element), free_free, tree->custom_arg);
-  /* This doesn't include key_size, but better than nothing */
-  tree->allocated-= sizeof(TREE_ELEMENT)+tree->size_of_element;
+  tree->allocated-= sizeof(TREE_ELEMENT) + tree->size_of_element + key_size;
   my_free((gptr) element,MYF(0));
   tree->elements_in_tree--;
   return 0;