On Wed, Jul 05, 2017 at 09:05:14PM +0100, Ramsay Jones wrote: > On 05/07/17 09:00, Jeff King wrote: > > Since its inception, the general strategy of the reflog-walk > > code has been to start with the tip commit for the ref, and > > as we traverse replace each commit's parent pointers with > > fake parents pointing to the previous reflog entry. > > > > This lets us traverse the reflog as if it were a real > > history, but it has some user-visible oddities. Namely: > > > > 1. The fake parents are used for commit selection and > > display. So for example, "--merges" or "--no-merges" > > are useful, because the history appears as a linear > > string. Likewise, pathspec limiting is based on the > > diff between adjacent entries, not the changes actually > > introduced by a commit. > > > > These are often the same (e.g., because the entry was > > just running "git commit" and the adjacent entry _is_ > > the true parent), but it may not be in several common > > cases. For instance, using "git reset" to jump around > > history, or "git checkout" to move HEAD. > > > > 2. We reverse-map each commit back to its reflog. So when > > it comes time to show commit X, we say "a-ha, we added > > X because it was at the tip of the 'foo' reflog, so > > let's show the foo reflog". But this leads to nonsense > > results when you ask to traverse multiple reflogs: if > > two reflogs have the same tip commit, we only map back > > to one of them. > > > > Instead, we should show each reflog individually, in > > the order the user gave us on the command line. > > > > 2. If the tip of the reflog and the ref tip disagree on > ^^ > It seems hard to get off the second point! ;-) Heh. You know, I even remember checking that I didn't screw that up (because I originally wrote the first and third, and later went back to add in the second point). But somehow I botched the proofreading, too. I'll plan to re-roll this to update the little bits you and Junio have pointed out. Junio, I'll probably just do the whole thing on "maint" and then the merge-up to "master" should be straight-forward, I'd think. -Peff
