writeTrashFile("file.txt", "content2");
git.add().addFilepattern("file.txt").call();
assertNotNull(git.commit().setMessage("edit file").call());
LockFile lf = new LockFile(db.getIndexFile(), db.getFS());
assertTrue(lf.lock());
try {
git.checkout().setName(commit1.name()).call();
fail("JGitInternalException not thrown");
} catch (JGitInternalException e) {
assertTrue(e.getCause() instanceof LockFailedException);