The *--bisect* flag limits output to the one commit object which is
roughly halfway between the included and excluded commits. Thus,
-if "git-rev-list --bisect foo ^bar ^baz" outputs 'midpoint', the output
-of "git-rev-list foo ^midpoint" and "git-rev-list midpoint ^bar ^baz"
+if 'git-rev-list --bisect foo ^bar ^baz' outputs 'midpoint', the output
+of 'git-rev-list foo ^midpoint' and 'git-rev-list midpoint ^bar ^baz'
would be of roughly the same length. Finding the change which introduces
a regression is thus reduced to a binary search: repeatedly generate and
test new 'midpoint's until the commit chain is of length one.