merged from MOODLE_15_STABLE: Clean up IP addresses from getremoteaddr. Otherwise we sometimes get weird results from proxies and inserts into mdl_log and mdl_user fail

lib/moodlelib.php

@@ -6334,17 +6334,24 @@ function unzip_show_status ($list,$removepath) {
  */
  function getremoteaddr() {
     if (!empty($_SERVER['HTTP_CLIENT_IP'])) {
-        return $_SERVER['HTTP_CLIENT_IP'];
+        return cleanremoteaddr($_SERVER['HTTP_CLIENT_IP']);
     }
     if (!empty($_SERVER['HTTP_X_FORWARDED_FOR'])) {
-        return $_SERVER['HTTP_X_FORWARDED_FOR'];
+        return cleanremoteaddr($_SERVER['HTTP_X_FORWARDED_FOR']);
     }
     if (!empty($_SERVER['REMOTE_ADDR'])) {
-        return $_SERVER['REMOTE_ADDR'];
+        return cleanremoteaddr($_SERVER['REMOTE_ADDR']);
     }
     return '';
 }
 
+/** 
+ * Cleans a remote address ready to put into the log table
+ */
+function cleanremoteaddr($addr) {
+    return preg_replace('/(\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3})(.*)/','$1',$addr);
+}
+
 /**
  * html_entity_decode is only supported by php 4.3.0 and higher
  * so if it is not predefined, define it here