Index: functions.php
===================================================================
--- functions.php	(revision 17563)
+++ functions.php	(working copy)
@@ -3250,6 +3250,9 @@
  * @return int An nonnegative integer
  */
 function absint( $maybeint ) {
+	if ( ! is_numeric( trim( $maybeint ) ) ) {
+		return 0;
+	}
 	return abs( intval( $maybeint ) );
 }