t / t4101 / diff.0-2on commit ref-filter: include reference to 'used_atom' within 'atom_value' (c58fc85)
   1--- a/frotz
   2+++ b/frotz
   3@@ -1,2 +1,2 @@
   4 a
   5-b
   6+b
   7\ No newline at end of file