? masquerade_ignore_anonymous_users.patch
Index: masquerade.module
===================================================================
RCS file: /cvs/drupal-contrib/contributions/modules/masquerade/masquerade.module,v
retrieving revision 1.16.2.39
diff -u -p -r1.16.2.39 masquerade.module
--- masquerade.module	23 Jun 2010 13:33:34 -0000	1.16.2.39
+++ masquerade.module	24 Jun 2010 12:11:06 -0000
@@ -34,6 +34,10 @@ function masquerade_perm() {
 function masquerade_init() {
   global $user;
 
+  if (empty($user->uid)) {
+    return;
+  }
+
   // load from table uid + session id
   $uid = db_result(db_query("SELECT uid_from FROM {masquerade} WHERE sid = '%s' AND uid_as = %d", session_id(), $user->uid));
   // using if so that we get unset rather than false if not masqing
@@ -632,7 +636,7 @@ function masquerade_switch_user_page($ui
  */
 function masquerade_switch_user($uid) {
   global $user;
-  if (!is_numeric($uid)) {
+   if (!is_numeric($uid) || empty($uid)) {
     drupal_set_message(t('A user id was not correctly passed to the switching function.'));
     watchdog('masquerade', 'The user id provided to switch users was not numeric.', NULL, WATCHDOG_ERROR);
     return drupal_goto(referer_uri());