[jedbrown]

Oh, I thought you meant updating the pull request by force-pushing on their branch. Your solution is racy, thus only acceptable for projects small enough that the likelihood of someone pulling during that window is sufficiently low.

[plorkyeran]

It's definitely not an option for very large projects, but projects small enough to have a very low chance of someone pulling in a several second window describes the vast majority of projects (and in general by the time it gets unsafe I'd expect fixing up incoming pull requests to be impractical time-wise anyway).