Index: sql/sql_acl.cc
===================================================================
--- sql/sql_acl.cc	(revision 863)
+++ sql/sql_acl.cc	(working copy)
@@ -1719,9 +1719,12 @@
 
 bool acl_check_host(const char *host, const char *ip)
 {
+  mysql_mutex_lock(&acl_cache->lock);
   if (allow_all_hosts)
+  {    
+    mysql_mutex_unlock(&acl_cache->lock);
     return 0;
-  mysql_mutex_lock(&acl_cache->lock);
+  }
 
   if ((host && my_hash_search(&acl_check_hosts,(uchar*) host,strlen(host))) ||
       (ip && my_hash_search(&acl_check_hosts,(uchar*) ip, strlen(ip))))