Index: t3lib/class.t3lib_div.php
===================================================================
--- t3lib/class.t3lib_div.php	(revision 8088)
+++ t3lib/class.t3lib_div.php	(working copy)
@@ -1272,14 +1272,14 @@
 	 *
 	 * @param	string		Full string to check
 	 * @param	string		Reference string which must be found as the "first part" of the full string
-	 * @return	boolean		True if $partStr was found to be equal to the first part of $str
+	 * @return	boolean		True if $partStr was found to be equal to the first part of $str and $partStr is not ''
 	 */
 	public static function isFirstPartOfStr($str,$partStr)	{
-		// Returns true, if the first part of a $str equals $partStr and $partStr is not ''
-		$psLen = strlen($partStr);
-		if ($psLen)	{
-			return substr($str,0,$psLen)==(string)$partStr;
-		} else return false;
+		if ($partStr === '') return false;
+		if (strpos($str, $partStr, 0) === 0) {
+			return true;
+		}
+		return false;
 	}
 
 	/**