JavaTestFilter is unable to parse paths containing %2F

When the current working dir path contains special chars used for URL encoding like "%2F" then buildr test fails with

gfiedler:~/workspace/foo%2Fbar> buildr test
(in /home/gfiedler/workspace/foo%2Fbar, development)
JavaTestFilter: Unable to load class dependency.InvocationTargetFieldMock to determine testing ability
ClassNotFoundException: dependency.InvocationTargetFieldMock
Buildr aborted!
RuntimeError : java.lang.ClassNotFoundException: dependency.InvocationTargetFieldMock

A fix would be to replace file.toURL() by file.toURI().toURL() in JavaTestFilter.java.