From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jonathan Nieder <jrnieder@gmail.com>
Subject: Re: Reachability lists in git
Date: Tue, 18 Nov 2014 12:32:04 -0800
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 <Pine.LNX.4.44L0.1411181523320.879-100000@iolanthe.rowland.org>
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To: Alan Stern <stern@rowland.harvard.edu>
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Alan Stern wrote:

> Tracking down regressions.  Bisection isn't perfect.  Suppose a
> bisection run ends up saying that B is the first bad commit.  It's easy
> enough to build B and test it, to verify that it really is bad.
>
> But to be sure that B introduced the fault, it would help to find the
> latest commit that doesn't include B's changes -- that is, the latest
> commit that B isn't reachable from (or the maximal elements in the set
> of all such commits).

Isn't that B^ (or B^ and B^2, if B is a merge)?