hbisect: do not assume that min(good) is an ancestor of min(bad) The included test used to report "inconsistent state", which is incorrect. While this situation cannot occur when the user sticks to the suggested bisect sequence. However, adding more consistent good/bad information to the bisect state should be tolerated as well.

hbisect: more consistent variable name

hbisect: confine loop to the relevant interval In this context we know that ancestors[rev] == None for all rev <= goodrev, so looping further back is unnecessary (and confusing).