Disallow merging if any of the commits in the PR contain strings like `revert me` or `do not merge`

[franciscoreinolds]

We were discussing offline and remembered this is not implemented but could easily be, when a colleague mentioned seeing deploys going out with that as the commit message.

[fatho]

I'm not sure how practical this is the way you suggest due to the Scunthorpe problem. For example, in the context of this very repository, it can be quite reasonable to have commit messages like "Implement 'revert merge' functionality" (containing revert me) or "Extend 'do not merge on Friday' functionality to holidays".

What we could perhaps go for is a clear and unambiguous marker like a prefix wip! (akin to the fixup! prefix). It is a lot less likely that such a marker is mistaken for something else than just a random substring of the message. That then shifts the feature from being a passive (but likely overzealous) guardian to requiring an active action to choose the wip! prefix, but then at least it won't get in the way unintentionally.

[ruuda]

On the other hand, it’s also not that hard to add an override command to say “merge regardless of the WIP safeguard” to work with false positives, though it does add complexity.

[fatho]

On the other hand, it’s also not that hard to add an override command to say “merge regardless of the WIP safeguard” to work with false positives, though it does add complexity.

But then you lose the safeguard completely, even though you might have a temporary WIP commit next to your intended "Implement 'revert merge' functionality" commit that you didn't want to merge.