MP preview diffs aren't always useful when generated against the target branch
| Affects | Status | Importance | Assigned to | Milestone | |
|---|---|---|---|---|---|
| Launchpad itself |
New
|
Undecided
|
Unassigned | ||
| git-ubuntu |
Triaged
|
Undecided
|
Unassigned | ||
Bug Description
In various git-ubuntu related workflows, the preview diff would be more helpful if generated against a branch that is different from the target branch.
In general terms this happens when we're "backporting" something somewhere. The target branch would end up effectively being force pushed. In this case, the previous contents of the target branch aren't really relevant; instead we would like to see a preview diff of something that force push would be closest too.
For example, if the MP represents an "Ubuntu package merge", then what we care about is the "new Ubuntu delta". IOW, that's the difference between the state of debian/sid and the proposed branch, rather than the difference between the state of the previous state of the branch and the proposed branch. The "Ubuntu->Ubuntu" diff may be useful to see too, but if we had to select a preferred diff base, it'd be the former.
Another example is when we're preparing a backport of a new version of a package to an older series. In this case we think it's more useful to use a diff base of the branch tip of where we're backporting from.
In practice, what we're ending up doing is supplying a target branch of what we want to use as the diff base. This works, except then the MP doesn't get automatically marked as Merged when the MP lands, because of course we update the "actual" target branch rather than what we told Launchpad.
I think maybe these user stories could be supported by Launchpad if the "Propose for merging" page allowed us to optionally specify a different "diff base" to use for preview diff generation instead of assuming that it is the target branch.
What do you think?
| Colin Watson (cjwatson) wrote | #1 |
| Robie Basak (racb) wrote | #2 |
| Changed in git-ubuntu: | |
| status: | New → Triaged |
| tags: | added: workflow |
| Andreas Hasenack (ahasenack) wrote | #4 |
| Andreas Hasenack (ahasenack) wrote | #5 |
Have you considered using a prerequisite branch? What you describe sounds quite similar to what that feature does. (Perhaps not identical, but since you didn't mention prerequisites at all I wondered if you knew about them.)