Create merge request from e-mail / patch

Description

In some projects it is common to contribute by e-mailing a patch a mailing list / maintainer. We already support creating issues by sending an e-mail. This idea can be extended to create a merge request from an e-mail (which contains a patch).

Proposal

Provide an "Email a new merge request to this project"-link like we do for issues. If an e-mail is sent to the GitLab instance, a new merge request is created on behalf of the user. This may require creating a fork first in case the user has no permission to create a branch within the target project.

Use cases

Projects which have a patch-by-email-workflow could then simply forward the patch to the GitLab instance.

Currently, they have to

  • fork the project if necessary
  • apply the patch to their working copy
  • commit and push the changes
  • create new merge request

Feature checklist

Make sure these are completed before closing the issue, with a link to the relevant commit.