- Small change that reduces the number of SQL queries when a certain role has
  no permissions set.

modules/user.module

@@ -214,8 +214,8 @@ function user_access($string) {
   ** To reduce the number of SQL queries, we cache the user's permissions
   ** in a static variable.
   */
-
-  if (!$perm) {
+  
+  if (isset($perm)) {
     if ($user->uid) {
       $perm = db_result(db_query("SELECT p.perm FROM role r, permission p WHERE r.rid = p.rid AND name = '%s'", $user->role), 0);
     }

modules/user/user.module

@@ -214,8 +214,8 @@ function user_access($string) {
   ** To reduce the number of SQL queries, we cache the user's permissions
   ** in a static variable.
   */
-
-  if (!$perm) {
+  
+  if (isset($perm)) {
     if ($user->uid) {
       $perm = db_result(db_query("SELECT p.perm FROM role r, permission p WHERE r.rid = p.rid AND name = '%s'", $user->role), 0);
     }