From d69250a969449da43891ef5b2859df77917183a8 Mon Sep 17 00:00:00 2001
From: "monty@mashka.mysql.fi" <>
Date: Wed, 2 Oct 2002 13:33:08 +0300
Subject: Fixes and code cleanups after merge with 4.0.3 Warning handling and
 initial prepared statement handling (last not complete yet) Changed a lot of
 functions that returned 0/1 to my_bool type. GRANT handling now uses
 read/write locks instead of mutex Change basic net functions to use THD
 instead of NET (needed for 4.1 protocol) Use my_sprintf instead of sprintf()
 + strlen() Added alloc_query() to be able to chare query initialization code
 with prepared statements. Cleanup handling of SHOW COUNT(*) WARNINGS and
 SELECT LAST_INSERT_ID()

Note that the following test fails (will be fixed ASAP):
sub_select, union, rpl_rotate_logs and rpl_mystery22
---
 mysys/tree.c | 25 ++++++++++++++++---------
 1 file changed, 16 insertions(+), 9 deletions(-)

(limited to 'mysys/tree.c')

diff --git a/mysys/tree.c b/mysys/tree.c
index 489262fcdc7..f72a4961312 100644
--- a/mysys/tree.c
+++ b/mysys/tree.c
@@ -17,26 +17,33 @@
 /*
   Code for handling red-black (balanced) binary trees.
   key in tree is allocated accrding to following:
-  1) If free_element function is given to init_tree or size < 0 then tree
-     will not allocate keys and only a pointer to each key is saved in tree.
-     key_sizes must be 0 to init and search.
+
+  1) If size < 0 then tree will not allocate keys and only a pointer to
+     each key is saved in tree.
+     compare and search functions uses and returns key-pointer
+
+  2) If size == 0 then there are two options:
+       - key_size != 0 to tree_insert: The key will be stored in the tree.
+       - key_size == 0 to tree_insert:  A pointer to the key is stored.
      compare and search functions uses and returns key-pointer.
-  2) if key_size is given to init_tree then each node will continue the
+
+  3) if key_size is given to init_tree then each node will continue the
      key and calls to insert_key may increase length of key.
      if key_size > sizeof(pointer) and key_size is a multiple of 8 (double
      allign) then key will be put on a 8 alligned adress. Else
      the key will be on adress (element+1). This is transparent for user
      compare and search functions uses a pointer to given key-argument.
-  3) If init_tree - keysize is 0 then key_size must be given to tree_insert
-     and tree_insert will alloc space for key.
-     compare and search functions uses a pointer to given key-argument.
+
+  - If you use a free function for tree-elements and you are freeing
+    the element itself, you should use key_size = 0 to init_tree and
+    tree_search
 
   The actual key in TREE_ELEMENT is saved as a pointer or after the
   TREE_ELEMENT struct.
   If one uses only pointers in tree one can use tree_set_pointer() to
   change address of data.
-  Copyright Monty Program KB.
-  By monty.
+
+  Implemented by monty.
 */
 
 #include "mysys_priv.h"
-- 
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