Elijah Newren <newren@xxxxxxxxx> writes: > On Tue, May 11, 2021 at 12:00 PM Sergey Organov <sorganov@xxxxxxxxx> wrote: >> >> Elijah Newren <newren@xxxxxxxxx> writes: >> >> > On Tue, May 11, 2021 at 7:03 AM Sergey Organov <sorganov@xxxxxxxxx> wrote: >> >> >> >> Junio C Hamano <gitster@xxxxxxxxx> writes: >> >> >> >> > Junio C Hamano <gitster@xxxxxxxxx> writes: >> >> >> >> [...] >> >> >> >> > If we enable "some kind of diff" for "-m", I actually think that by >> >> > default "git log -m" should be turned into "log --cc". As you told >> >> > Alex in your response, "log -m -p" is a quite unpleasant format to >> >> > read---it is there only because it was the only thing we had before >> >> > we invented "-c/--cc". >> >> >> >> Please, no! --cc has unfortunate feature of outputting exactly nothing >> >> for a lot of merge commits, causing even more confusion than historical >> >> "-m -p" format. >> >> >> >> The best default for -m output is --diff-merges=first-parent. Everybody >> >> is familiar with it, and it's useful. >> >> >> >> > But that might be outside the scope of this series. I dunno, but if >> >> > there is no other constraints (like backward compatibility issues), >> >> > I have a moderately strong preference to use "--cc" over "-m -p" >> >> > from the get go for unconfigured people, rather than forcing >> >> > everybody to configure >> >> >> >> I rather have strong preference for --diff-merges=first-parent. --cc is >> >> only suitable for Git experts, and they know how to get what they want >> >> anyway. Yep, by using --cc. Why spare yet another short option for that? >> > >> > Interesting. I have a strong preference for --diff-merges=remerge >> > (yeah, I know it's not upstream, but it's been ready to submit for >> > months, but just backed up behind the other ort changes. Sorry, I >> > can't push those through any faster). I've had others using it for >> > about 9 months now. >> >> Once somebody uses it for 9 months and starts to understand what it is >> and really loves it, she can still set log.diffMerges=remerge (new >> feature) and have fun. >> >> > >> > I think --cc is a lot better than -m for helping you find what users >> > changed when they did the merge, >> >> Yes, but it doesn't mean it should be the default. > > I didn't say it should be. > >> In my workflows, the first thing that matters is what commit did what >> changes on the current branch. I don't typically care what the user >> changed during the merge operation, only about the result. If I do care, >> then only after I find the merge commit is responsible, and I can then >> use --cc if I want to. >> >> > but I agree the format is somewhat difficult for many users to >> > understand. (--diff-merges=remerge, or --remerge-diff, fixes these >> > problems, IMO.) I think --diff-merges=first-parent, while fine when >> > explicitly requested on the command line, would be wildly misleading >> > as a default because it would attribute changes to a merge commit that >> > were made elsewhere. >> >> No, it's exactly this merge commit that made these changes to the >> current branch. The changes you refer to have been made on another >> branch, and not by this particular merge commit, and we fortunately have >> the reference to those commits through the second parent of this one. > > If you only care about "what introduced these changes to the current > branch", then it's not only the diff against second parent that is > irrelevant: ALL commits that are part of the history only via the > second or later parents are also irrelevant and thus you should be > using --first-parent when asking this question. That changes both > history traversal and the diff output. No, it's exactly why I don't always want --first-parent. I want to traverse *all* the history, yet to see what's changed by every commit on *this* branch in the process of traversal, be it a merge on not a merge commit. Thanks, -- Sergey Organov
