Static Route Parts are not reset
StaticRoutePart::resolve() sets the value to the route parts name (= the corresponding URI part).
RoutePart::match() merges the route parts value into the resulting request arguments. The value of the route part must be reset to NULL before the route parth is processed.
The StaticRoutePart currently fails to do so. Usually this has no effect because match() is always called before resolve() but it fails when using FLOW3 with an app server like AiP.