From: Francis Moreau Date: Thu, 08 Sep 2011 07:10:08 GMT Subject: Re: git-rebase skips automatically no more needed commits Message-ID: In-Reply-To: <7vk49k48q4.fsf@alter.siamese.dyndns.org> On Wed, Sep 7, 2011 at 6:29 PM, Junio C Hamano wrote: > Francis Moreau writes: > >> If I start the rebase process with : "git rebase -i -p master foo" >> then the filtering is happening. Here 'foo' has been created with >> v2.6.39 tag as start point and contains some patches cherry-picked >> from the upstream. >> >> However if I call git-rebase this way: "git rebase -i -p --onto master >> v2.6.39 foo", then it seems that no filtering is done. >> >> Is that expected ? > > Because "rebase --onto A B C" has to be usable when commit A does not have > any ancestry relationship with the history between B and C, But is it the common case ? That would mean that A and B are part of totaly independant branches which is not that common I think. I'm using "git rebase --onto A B C" because I want to simplify git's work. I know that any commits between A..B are already in A history and I'm not interested in rebasing them anyways. > I wouldn't be > surprised if the command does not look at commits on the history that lead > to A that _might_ be related to the ones between B and C. It does not know > how far to dig from A and stop, and obviously you do not want to dig down > to the beginning of the history. "rebase A B" on the other hand can safely > stop digging the history back from A down to where the history leading to > B forked (i.e. merge base between A and B). Hmm I dont understand why "rebase --onto A B C" wouldn't try to find the merge base between A and B. If it doesn't (which is quite uncommon I guess) then don't do the filtering as we're currently doing but if there's a merge base (common case) then do the filtering. No ? -- Francis