2018-01-08 17:42 GMT+03:00 Matwey V. Kornilov <matwey.kornilov@xxxxxxxxx>: > 2018-01-08 16:56 GMT+03:00 Johannes Schindelin <Johannes.Schindelin@xxxxxx>: >> Hi Matwey, >> >> On Mon, 8 Jan 2018, Matwey V. Kornilov wrote: >> >>> I think that rebase preserve-merges algorithm needs further >>> improvements. Probably, you already know it. >> >> Yes. preserve-merges is a fundamentally flawed design. >> >> Please have a look here: >> >> https://github.com/git/git/pull/447 >> >> Since we are in a feature freeze in preparation for v2.16.0, I will >> submit these patch series shortly after v2.16.0 is released. >> >>> As far as I understand the root cause of this that when new merge >>> commit is created by rebase it is done simply by git merge >>> $new_parents without taking into account any actual state of the >>> initial merge commit. >> >> Indeed. preserve-merges does not allow commits to be reordered. (Actually, >> it *does* allow it, but then fails to handle it correctly.) We even have >> test cases that mark this as "known breakage". >> >> But really, I do not think it is worth trying to fix the broken design. >> Better to go with the new recreate-merges. (I am biased, of course, >> because I invented recreate-merges. But then, I also invented >> preserve-merges, so ...) > > Well. I just checked --recreate-merges=no-rebase-cousins from the PR > and found that it produces the same wrong result in my test example. > The topology is reproduced correctly, but merge-commit content is > broken. > I did git rebase --recreate-merges=no-rebase-cousins --onto abc-0.1 v0.1 abc-0.2 Indeed, exactly as you still say in the documentation: "Merge conflict resolutions or manual amendments to merge commits are not preserved." My initial point is that they have to be preserved. Probably in recreate-merges, if preserve-merges is discontinued. > >> >> Ciao, >> Johannes >> > > > > -- > With best regards, > Matwey V. Kornilov -- With best regards, Matwey V. Kornilov
