bdiff: switch to lyhash lyhash is a very simple and fast hash function that had the fewest hash collisions on a 3.9M line text corpus and 190k line binary corpus and should have significantly fewer collisions than the current hash function.

adding a
adding b/a
a
b/a
644 a
644 b/a
b789fdd96dc2f3bd229c1dd8eedf0fc60e2b68e3 644 a
b789fdd96dc2f3bd229c1dd8eedf0fc60e2b68e3 644 b/a
a
a
b/a
a
b/a
% should fail
abort: unknown revision '2'!
abort: please specify just one revision
a
b/a