copyFile(dir, "segments_2", "segments");
copyFile(dir, "segments_2", "segments_1");
// Create a bogus cfs file shadowing a non-cfs segment:
assertTrue(dir.fileExists("_3.fdt"));
assertTrue(!dir.fileExists("_3.cfs"));
copyFile(dir, "_1.cfs", "_3.cfs");
String[] filesPre = dir.listAll();
// Open & close a writer: it should delete the above 4