fixed:

==2761== Thread 10:
==2761== Conditional jump or move depends on uninitialised value(s)
==2761==    at 0x81913BB: find_best(JOIN*, unsigned long long, unsigned, double, double) (sql_select.cc:2689)
==2761==    by 0x8191030: find_best_combination(JOIN*, unsigned long long) (sql_select.cc:2599)


sql/sql_select.cc:
  keypart_map fiels should be initialized in case of fulltext index

sql/sql_select.cc

@@ -2408,6 +2408,7 @@ add_ft_keys(DYNAMIC_ARRAY *keyuse_array,
   keyuse.keypart= FT_KEYPART;
   keyuse.used_tables=cond_func->key_item()->used_tables();
   keyuse.optimize= 0;
+  keyuse.keypart_map= 0;
   VOID(insert_dynamic(keyuse_array,(gptr) &keyuse));
 }