From mboxrd@z Thu Jan  1 00:00:00 1970
From: Junio C Hamano <gitster@pobox.com>
Subject: Re: [PATCH] rebase: use reflog to find common base with upstream
Date: Thu, 24 Oct 2013 12:04:24 -0700
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Cc: John Keeping <john@keeping.me.uk>, git <git@vger.kernel.org>,
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To: Martin von Zweigbergk <martinvonz@gmail.com>
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Martin von Zweigbergk <martinvonz@gmail.com> writes:

> I think
>
>   git merge-base HEAD $(git rev-list -g "$upstream_name")
>
> is roughly correct and hopefully fast enough. That can lead to too
> long a command line, so I was planning on teaching merge-base a
> --stdin option, but never got around to it.

Sorry for coming in late.

I think the above with s/HEAD/$curr_branch/ is a good way to compute
what the whole "for reflog in $(git rev-list -g $remoteref" loop
computes when one of the historic tips recorded in the reflog was
where $curr_branch forked from, i.e. the loop actually finds at
least one ancestor in the reflog and breaks out after setting
oldremoteref.  But it would give a completely different commit if
none of the reflog entries is a fork point.

A two patch series forthcoming.