formatters/BasicFormatter.php's format() and includes/EmailFormatter.php getNotifIcon() were already duplicating code to determine the URL of a notification icon. With the fix for bug 58705 it's 20 lines of identical code.
The only difference between them is getNotifIcon() calls wfExpandUrl(); this e.g. could be an optional parameter to a common function or method.
Version: master
Severity: normal