SquirrelMail

http://squirrelmail.svn.sourceforge.net/viewvc/squirrelmail/trunk/squirrelm
ail/functions/mime.php?r1=10655&r2=10703

Fix is not ported from devel. If you read message attached message/rfc822
part and return to main message, sender is displayed as "Unknown sender" in
list of attachments.

If 1.4.10-dev formatAttachments() checks only for object. In 1.5.2-dev
buildAttachmentArray() checks for object and array.