Re: Squash & Merge Implementation
- From
Jeff King <peff@peff.net>
- Date
- Aug 3, 2018, 13:49 UTC
- Message-ID
- <20180803134901.GC28939@sigill.intra.peff.net>
- In-Reply-To
- <CALr1GiFBm9zJ1v-UWuVLWJJ+zFh-iTKOv=T4KETLN8qkW_0pAg@mail.gmail.com>
On Fri, Aug 03, 2018 at 03:01:15PM +0300, Vadim Belov wrote:
Show 5 quoted lines
> 1. This merges successfully without squash:
> git checkout origin/master
> git merge ${PR-Branch}
> git push origin HEAD:master
> git push origin --delete ${PR-Branch}Right, this is a normal merge.
Show 5 quoted lines
> 2. This closes the PR, but there is no update seen on master:
> git checkout origin/master
> git merge --squash --commit ${PR-Branch}
> git push origin HEAD:master
> git push origin --delete ${PR-Branch}Doing "merge --squash --commit" doesn't do what you expect; namely "--commit" does not override the non-committing nature of "--squash". It only override a "--no-commit" found elsewhere.
IMHO this is something that could be improved in Git (i.e., telling the difference between "the user did not say --no-commit" and "the user said --commit" and respecting it for --squash).
But that explains what you see. The push to master is a noop, since you didn't make a new commit. And then deleting the PR branch on GitHub auto-closes the PR.
Show 7 quoted lines
> 3. This fails to push to master with the error "GH006: Protected branch
> update failed" (despite that the PR is set to SUCCESS):
> git checkout origin/master
> git merge --squash ${PR-Branch}
> git commit -am"comment"
> git push origin HEAD:${m_mainBranch}
> git push origin --delete ${m_prBranch}So here you _do_ make an actual commit. But that commit doesn't look like a merge to the receiver; it just looks like a single commit that has all the changes there were on PR-Branch.
The tree of that commit should be the same tree that would result from a real merge. So in theory things like protected-branch status checks could handle that, but I suspect they use the actual commit id (the tree id is fine if you're just doing CI, but if you wanted to have a status check for commit messages, say, you'd obviously want that to be tied to the actual commit object).
I don't offhand recall how that is implemented (and you could also be falling afoul of other checks, like required reviews). But this is a GitHub-specific question, and you should probably ask GitHub support to go further.
-Peff