also be a further fix-up C' on the side branch. "diff Y^..Y" is similar
to "diff -R W^..W" (which in turn means it is similar to "diff M^..M"),
and "diff A'^..C'" by definition would be similar but different from that,
also be a further fix-up C' on the side branch. "diff Y^..Y" is similar
to "diff -R W^..W" (which in turn means it is similar to "diff M^..M"),
and "diff A'^..C'" by definition would be similar but different from that,