I ran into a need to test some functionality that relies on system properties. Writing the test was error-prone because the properties persist across the jvm so if you set them in a test they leak across to other tests unless you are careful about @After methods. It occurred to me it would be nice if LuceneTestCase would detect this and yell. It could save all the system properties before each test (or at least each test class) and see if they are restored at the end. I don't know if this arises much in Lucene, but maybe in Solr?
-Mike
