Re: git-rebase skips automatically no more needed commits

On Wed, Sep 7, 2011 at 6:29 PM, Junio C Hamano [off-list ref] wrote:

Francis Moreau [off-list ref] writes:

quoted

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