Jeff King <peff@xxxxxxxx> writes: > Is it that cheap? A full reachability check for something that is not in > any ref would involve going to the roots, wouldn't it? You only need to dig until you hit a merge base, no? In this case, you would need to compute just one merge base, between the commit you are about to leave, and the (imaginary) commit that is a merge across all the tips of your refs. If the merge base is the commit you are about to leave, you were sightseeing in the past without creating anything new, otherwise you will lose commits between the computed base and the commit you are about to leave. And merge-base has an interface to compute exactly that, I think. -- To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html