Merge macbook.gmz:/Users/kgeorge/mysql/work/mysql-5.0-opt

into  macbook.gmz:/Users/kgeorge/mysql/work/merge-5.1-opt

sql/opt_range.cc

@@ -276,6 +276,9 @@ class SEL_ARG :public Sql_alloc
   Field *field;
   uchar *min_value,*max_value;			// Pointer to range
 
+  /*
+    eq_tree() requires that left == right == 0 if the type is MAYBE_KEY.
+   */
   SEL_ARG *left,*right;   /* R-B tree children */
   SEL_ARG *next,*prev;    /* Links for bi-directional interval list */
   SEL_ARG *parent;        /* R-B tree parent */
@@ -291,7 +294,7 @@ class SEL_ARG :public Sql_alloc
   SEL_ARG(Field *field, uint8 part, uchar *min_value, uchar *max_value,
 	  uint8 min_flag, uint8 max_flag, uint8 maybe_flag);
   SEL_ARG(enum Type type_arg)
-    :min_flag(0),elements(1),use_count(1),left(0),next_key_part(0),
+    :min_flag(0),elements(1),use_count(1),left(0),right(0),next_key_part(0),
     color(BLACK), type(type_arg)
   {}
   inline bool is_same(SEL_ARG *arg)