Branch names with slashes appear to break URL generation

While on a branch pawel/connect_to_prometheus_through_proxy-30480 I attempted to run the GitLab: Open active file on GitLab command and it sent me to:

https://gitlab.com/gitlab-org/gitlab-ce/blob/pawel/app/assets/javascripts/monitoring/components/dashboard.vue#L22

Instead of:

https://gitlab.com/gitlab-org/gitlab-ce/blob/pawel/connect_to_prometheus_through_proxy-30480/app/assets/javascripts/monitoring/components/dashboard.vue#L22

I think it is the / character in the branch name that causes this.