diff -r 7267c2a67a93 -r ed06961e54dd includes/functions.php
--- a/includes/functions.php	Sun Jul 01 17:12:42 2007 -0400
+++ b/includes/functions.php	Mon Jul 02 15:17:54 2007 -0400
@@ -2197,9 +2197,18 @@
 
 function dirtify_page_id($page_id)
 {
+  global $db, $session, $paths, $template, $plugins; // Common objects
   // First, replace spaces with underscores  
   $page_id = str_replace(' ', '_', $page_id);
   
+  // Exception for userpages for IP addresses
+  if ( preg_match('/^' . preg_quote($paths->nslist['User']) . '/', $page_id) )
+  {
+    $ip = preg_replace('/^' . preg_quote($paths->nslist['User']) . '/', '', $page_id);
+    if ( is_valid_ip($ip) )
+      return $page_id;
+  }
+  
   preg_match_all('/\.[A-Fa-f0-9][A-Fa-f0-9]/', $page_id, $matches);
   
   foreach ( $matches[0] as $id => $char )
@@ -2269,6 +2278,24 @@
   return "{$str1}{$needle}{$str2}";
 }
 
+/**
+ * Tells if a given IP address is valid.
+ * @param string suspected IP address
+ * @return bool true if valid, false otherwise
+ */
+ 
+function is_valid_ip($ip)
+{
+  // These came from phpBB3.
+  $ipv4 = '(?:(?:\d{1,2}|1\d\d|2[0-4]\d|25[0-5])\.){3}(?:\d{1,2}|1\d\d|2[0-4]\d|25[0-5])';
+  $ipv6 = '(?:(?:(?:[\dA-F]{1,4}:){6}(?:[\dA-F]{1,4}:[\dA-F]{1,4}|(?:(?:\d{1,2}|1\d\d|2[0-4]\d|25[0-5])\.){3}(?:\d{1,2}|1\d\d|2[0-4]\d|25[0-5])))|(?:::(?:[\dA-F]{1,4}:){5}(?:[\dA-F]{1,4}:[\dA-F]{1,4}|(?:(?:\d{1,2}|1\d\d|2[0-4]\d|25[0-5])\.){3}(?:\d{1,2}|1\d\d|2[0-4]\d|25[0-5])))|(?:(?:[\dA-F]{1,4}:):(?:[\dA-F]{1,4}:){4}(?:[\dA-F]{1,4}:[\dA-F]{1,4}|(?:(?:\d{1,2}|1\d\d|2[0-4]\d|25[0-5])\.){3}(?:\d{1,2}|1\d\d|2[0-4]\d|25[0-5])))|(?:(?:[\dA-F]{1,4}:){1,2}:(?:[\dA-F]{1,4}:){3}(?:[\dA-F]{1,4}:[\dA-F]{1,4}|(?:(?:\d{1,2}|1\d\d|2[0-4]\d|25[0-5])\.){3}(?:\d{1,2}|1\d\d|2[0-4]\d|25[0-5])))|(?:(?:[\dA-F]{1,4}:){1,3}:(?:[\dA-F]{1,4}:){2}(?:[\dA-F]{1,4}:[\dA-F]{1,4}|(?:(?:\d{1,2}|1\d\d|2[0-4]\d|25[0-5])\.){3}(?:\d{1,2}|1\d\d|2[0-4]\d|25[0-5])))|(?:(?:[\dA-F]{1,4}:){1,4}:(?:[\dA-F]{1,4}:)(?:[\dA-F]{1,4}:[\dA-F]{1,4}|(?:(?:\d{1,2}|1\d\d|2[0-4]\d|25[0-5])\.){3}(?:\d{1,2}|1\d\d|2[0-4]\d|25[0-5])))|(?:(?:[\dA-F]{1,4}:){1,5}:(?:[\dA-F]{1,4}:[\dA-F]{1,4}|(?:(?:\d{1,2}|1\d\d|2[0-4]\d|25[0-5])\.){3}(?:\d{1,2}|1\d\d|2[0-4]\d|25[0-5])))|(?:(?:[\dA-F]{1,4}:){1,6}:[\dA-F]{1,4})|(?:(?:[\dA-F]{1,4}:){1,7}:))';
+  
+  if ( preg_match("/^{$ipv4}$/", $ip) || preg_match("/^{$ipv6}$/", $ip) )
+    return true;
+  else
+    return false;
+}
+
 //die('<pre>Original:  01010101010100101010100101010101011010'."\nProcessed: ".uncompress_bitfield(compress_bitfield('01010101010100101010100101010101011010')).'</pre>');
 
 ?>