Plugin "Pull requests" for mercurial

Plugin with "pull-request" functionality for HG. Is there such plugin?

Pull requests are inherently a repository hosting-platform specific function, it isn’t something that can be added to Mercurial as an extension. How would you imagine that it should work?

If you’re looking for a Mercurial equivalent of GitHub pull requests; Bitbucket offers free Mercurial hosting and has pull request functionality.

There doesn't seem to be an extension directly named after that feature (the GitHub "Pull Request"), but you could emulate it through an integration with a review system, as described in "Review Board workflow for Mercurial repository".

The Mercurial Review Board extension (repo here) could be used to link your DVCS to ReviewBoard, helping you to only pull what has been reviewed.