[External] : Backporting a set of patches in a single commit

[Kevin Rushforth]

Hi Christoph,

Yes, I think one solution would be to enable the dependent pull request 
feature of Skara for your repo. It's already being used by the jdk 
project. Since it is already implemented and tested (at least for 
original fixes, but I can't think of anything that would preclude it for 
backports), it would be easy to set up so you could try it and see if it 
met your needs.

FWIW, I ran into this in a couple cases myself when backporting fixes to 
jfx11u after the Skara switch. I ended up testing them in a branch where 
I pulled in the relevant fixes I needed, and then did them as separate 
PRs in the right order. Since they were clean it took only a few extra 
minutes. It was the testing that took all the time anyway, but I 
couldn't help thinking that dependent pull requests would have made it 
easier.

-- Kevin


On 7/21/2021 2:20 PM, Langer, Christoph wrote:
>
> Hi Skara Team,
>
> after gathering the first significant experiences with the backport 
> process using GitHub/Skara, I find that there is one use case which 
> works considerably worse than before. It is when you want to backport 
> a set of patches that must be pushed together. Imagine you have a 
> patch, then a build fix and then maybe another test fix. So as to not 
> break builds and tests, you will want to push them together in one go. 
> You could now add those 3 commits into one PR. But when you integrate, 
> the 3 commits get squashed which is contrary to the usual way of 
> backporting which tries to preserve individual commits. Alternatively, 
> you could file 3 separate PRs. This, however, often bears the problem 
> that the PRs might be dependent on each other. So any individual 
> backport PR could possibly only be opened and reviewed after its 
> predecessor was integrated. Which will leave the repo in a bad state 
> for a while.
>
> So what can we do here? Shall we change the paradigm and allow more 
> squashing? Or did you already think of a better workflow? I think 
> there is a feature of Skara called dependent PRs. Could that be used 
> here? Or could maybe the backport bot recognize individual commits to 
> preserve?
>
> Thanks in advance for sharing your thoughts.
>
> Best regards
>
> Christoph
>