Re: [PATCH 13/22] sequencer: remember the onelines when parsing the todo file

From: Junio C Hamano <gitster@pobox.com>
Date: Sep 1, 2016, 18:47 UTC
Message-ID: <xmqqeg53wj7a.fsf@gitster.mtv.corp.google.com>
In-Reply-To: <alpine.DEB.2.20.1609011052260.129229@virtualbox>

Johannes Schindelin <Johannes.Schindelin@gmx.de> writes:

Show 10 quoted lines

>> though).  The "one sequencer to rule them all" may even have to say
>> "now give name ':1' to the result of the previous operation" in one
>> step and in another later step have an instruction "merge ':1'".
>> When that happens, you cannot even pre-populate the commit object
>> when the sequencer reads the file, as the commit has not yet been
>> created at that point.
>
> These considerations are pretty hypothetical. I would even place a bet
> that we will *never* have ":1" as names, not if I have anything to say...
> ;-)

If you can always work with pre-existing commit, then you can validate all object references that appear in the instructions upfront.

I was sort of expecting that, when you do the preserve-merges mode of "rebase -i", you would need to jump around, doing "we have reconstructed the side branch on a new 'onto', let's give the result this temporary name ':1', and then switch to the trunk (which would call for 'reset <commit>' instruction) and merge that thing (which would be 'merge :1' or perhaps called 'pick :1')", and at that point you no longer validate the object references upfront.

If you do not have to have such a "mark this point" and a "refer to that point we previously marked", then I agree that you should be able to pre-validate and keep the result in the structure.