There is a bug in the commons-fileupload code. On a multipart post, the boundary
string is converted to a byte array using the platform's default encoding
instead of using 8859-1. This was reported as Bugzilla COM-1057
(
http://issues.apache.org/bugzilla/show_bug.cgi?id=26194
) and has been fixed in
the source code. However, there hasn't yet been an official release of the new
fileupload stuff, and it looks like the latest nightly build breaks other items
with multipart posts.
This can be fixed with 1) a new stable release of commons-fileupload and 2)
updating Tomcat to that new stable release