t / t4101 / diff.1-3on commit tests: use "git xyzzy" form (t0000 - t3599) (0cb0e14)
   1--- a/frotz
   2+++ b/frotz
   3@@ -1,3 +1,3 @@
   4 a
   5-b
   6 c
   7+b
   8\ No newline at end of file