Re: [PATCH v2 01/10] technical doc: add a design doc for the evolve command

> Phillip Wood wrote:
>> On 10/10/2022 20:35, Victoria Dye wrote:
>>> Stefan Xenos via GitGitGadget wrote:
>>> 3. Can't handle multiple changes sharing the same parent when the parent
>>>      needs to be rebased
>>>      - Since the introduction of '--update-refs' [1], this is technically
>>>        possible (although it needs a UI for the use case you mentioned).
>>
>> '--update-refs' is more limited though I think. With evolve if I have
>>
>>                    D (topic-2)
>>                   /
>>      A - B - C (topic-1)
>>                   \
>>                    E (topic-3)
>>
>> then if I checkout topic-1 and amend one of the commits I can run "git
>> evolve" to automatically rebase topic-2 & topic-3. One cannot do that with
>> "rebase --update-refs". We could extend rebase (or have a new command) so
>> that users can say "amend commit X and rebase all the branches that contain
>> it".
> 
> Sorry, let me clarify what I mean. The 'update-ref' command in a
> 'rebase-todo' script (not the '--update-refs' option) can be used to create
> a rebase script that does what's described in your example:
> 
>    label onto # A
> 
>    reset onto
>    pick 1342ab B
>    fixup 8a7f3e fixup! B
>    label branch-point-1
> 
>    pick 90d7fc C
>    label topic-1
>    update-ref refs/heads/topic-1
> 
>    reset branch-point-1
>    pick 42f92b D
>    label topic-2
>    update-ref refs/heads/topic-2
> 
>    reset branch-point-1
>    pick 06d8ec E
>    label topic-3
>    update-ref refs/heads/topic-3
> 
> So, while it'd need a less manual UI (e.g., a 'rebase --evolve' option) to
> generate that script, the 'update-ref' command makes this functionality
> possible in a rebase.