Branch push does not trigger pipeline for external pull request
In the verification stage of https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/15082 I found out that the feature partially works on staging environment.
What works?
- opening a pull request triggers correctly a pipeline for external pull request
- reopening a pull request triggers correctly a pipeline for external pull request
What does not work?
- when changes are pushed to the branch and a pull request is open for it, it only triggers a pipeline for the branch push, not the pipeline for the pull request