Index: includes/session.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/session.inc,v
retrieving revision 1.28
diff -u -F^f -r1.28 session.inc
--- includes/session.inc	7 May 2006 00:08:36 -0000	1.28
+++ includes/session.inc	15 Aug 2006 07:34:36 -0000
@@ -74,8 +74,29 @@ function sess_write($key, $value) {
   return TRUE;
 }
 
-function sess_destroy($key) {
-  db_query("DELETE FROM {sessions} WHERE sid = '%s'", $key);
+/**
+ * Called by PHP session handling with the PHP session ID to end a user's session.
+ * Can also be called directly, either with the PHP session ID or another identifier
+ * such as uid to end a specific user's session.
+ *
+ * @param  string $key
+ * @param  string $type
+ *   Possible values:
+ *     sid (default): the PHP session id
+ *     uid: the Drupal user id
+ *     hostname: a hostname (usually an IP address)
+ */
+function sess_destroy($key, $type = 'sid') {
+  // validate $type stringently to avoid all chance of SQL injection
+  switch ($type) {
+    case 'sid':
+    case 'uid':
+    case 'hostname':
+      break;
+    default:
+      $type = 'sid';
+  }
+  db_query('DELETE FROM {sessions} WHERE '. $type. " = '%s'", $key);
 }
 
 function sess_gc($lifetime) {
@@ -89,3 +110,30 @@ function sess_gc($lifetime) {
   return TRUE;
 }
 
+/**
+ * Called when an anonymous user becomes an authenticated or vise-versa.
+ */
+function sess_regenerate() {
+  $old_session_id = session_id();
+  session_regenerate_id();
+  db_query("UPDATE {sessions} SET sid = '%s' WHERE sid = '%s'", session_id(), $old_session_id);
+}
+
+/**
+ * Counts how many users have sessions. Can count either anonymous sessions, authenticated sessions, or both.
+ *
+ * @param int $timestamp
+ *   A Unix timestamp representing a point of time in the past.
+ *   The default is 0, which counts all existing sessions.
+ * @param int $anonymous
+ *   true for anonymous users.
+ *   false for authenticated users.
+ *   Any other value will return the count of both authenticated and anonymous users.
+ * @return  int
+ *   The number of users with sessions.
+ */
+function drupal_count_sessions($timestamp = 0, $anonymous = true) {
+  $query = ($anonymous) ? ' AND uid = 0' : ' AND uid > 0';
+  $result = db_fetch_object(db_query('SELECT COUNT(sid) AS count FROM {sessions} WHERE timestamp >= %d'. $query, $time_period));
+  return $result->count;
+}
Index: modules/user/user.module
===================================================================
RCS file: /cvs/drupal/drupal/modules/user/user.module,v
retrieving revision 1.653
diff -u -F^f -r1.653 user.module
--- modules/user/user.module	14 Aug 2006 20:35:11 -0000	1.653
+++ modules/user/user.module	15 Aug 2006 07:34:37 -0000
@@ -148,7 +148,7 @@ function user_save($account, $array = ar
 
     // Delete a blocked user's sessions to kick them if they are online.
     if (isset($array['status']) && $array['status'] == 0) {
-      db_query('DELETE FROM {sessions} WHERE uid = %d', $account->uid);
+      sess_destroy($account->uid, 'uid');
     }
 
     // Refresh user object
@@ -553,19 +553,19 @@ function user_block($op = 'list', $delta
       case 3:
         if (user_access('access content')) {
           // Count users with activity in the past defined period.
-          $time_period = variable_get('user_block_seconds_online', 900);
+          $time_period = time() - variable_get('user_block_seconds_online', 900);
 
           // Perform database queries to gather online user lists.
-          $guests = db_fetch_object(db_query('SELECT COUNT(sid) AS count FROM {sessions} WHERE timestamp >= %d AND uid = 0', time() - $time_period));
-          $users = db_query('SELECT uid, name, access FROM {users} WHERE access >= %d AND uid != 0 ORDER BY access DESC', time() - $time_period);
+          $guests = drupal_count_sessions($time_period);
+          $users = db_query('SELECT uid, name, access FROM {users} WHERE access >= %d AND uid != 0 ORDER BY access DESC', $time_period);
           $total_users = db_num_rows($users);
 
           // Format the output with proper grammar.
-          if ($total_users == 1 && $guests->count == 1) {
-            $output = t('There is currently %members and %visitors online.', array('%members' => format_plural($total_users, '1 user', '%count users'), '%visitors' => format_plural($guests->count, '1 guest', '%count guests')));
+          if ($total_users == 1 && $guests == 1) {
+            $output = t('There is currently %members and %visitors online.', array('%members' => format_plural($total_users, '1 user', '%count users'), '%visitors' => format_plural($guests, '1 guest', '%count guests')));
           }
           else {
-            $output = t('There are currently %members and %visitors online.', array('%members' => format_plural($total_users, '1 user', '%count users'), '%visitors' => format_plural($guests->count, '1 guest', '%count guests')));
+            $output = t('There are currently %members and %visitors online.', array('%members' => format_plural($total_users, '1 user', '%count users'), '%visitors' => format_plural($guests, '1 guest', '%count guests')));
           }
 
           // Display a list of currently online users.
@@ -922,10 +922,7 @@ function user_login_submit($form_id, $fo
 
     user_module_invoke('login', $form_values, $user);
 
-    $old_session_id = session_id();
-    session_regenerate_id();
-    db_query("UPDATE {sessions} SET sid = '%s' WHERE sid = '%s'", session_id(), $old_session_id);
-
+    sess_regenerate();
   }
 }
 
@@ -1419,8 +1416,8 @@ function user_edit($category = 'account'
  */
 function user_delete($edit, $uid) {
   $account = user_load(array('uid' => $uid));
+  sess_destroy($uid, 'uid');
   db_query('DELETE FROM {users} WHERE uid = %d', $uid);
-  db_query('DELETE FROM {sessions} WHERE uid = %d', $uid);
   db_query('DELETE FROM {users_roles} WHERE uid = %d', $uid);
   db_query('DELETE FROM {authmap} WHERE uid = %d', $uid);
   $array = array('%name' => theme('placeholder', $account->name), '%email' => theme('placeholder', '<'. $account->mail .'>'));