On Fri, Nov 4, 2016 at 6:57 PM, Junio C Hamano <gitster@xxxxxxxxx> wrote: > > Imagine we invent a new tree entry type, "gitref", that is similar > to "gitlink" in that it can record a commit object name in a tree, > but unlike "gitlink" it does imply reachability. And you do not add > phony parents to your commit object. A tree that has "gitref"s in > it is about annotating the commits in the same repository (e.g. the > tree references two commits, "base" and "tip", to point into a slice > of the main history). And it is perfectly sensible for such a > pointer to imply reachability---after all it serves different > purposes from "gitlink". The more I think about this (and also about how to limit ref advertisements as recently discussed in https://public-inbox.org/git/20161024132932.i42rqn2vlpocqmkq@xxxxxxxxxxxxxxxxxxxxx/), the more I think about Shawn's RefTree: https://public-inbox.org/git/CAJo=hJvnAPNAdDcAAwAvU9C4RVeQdoS3Ev9WTguHx4fD0V_nOg@xxxxxxxxxxxxxx/ Couldn't a RefTree be used to store refs that point to the base commit, the tip commit and the blob that contains the cover letter, and maybe also a ref pointing to the RefTree of the previous version of the series?