Stage names are double escaped in when output in HTML on GitLab

Summary

CI/CD stages with a & in the name get rendered as &; the HTML is doubly escaped.

Steps to reproduce

Name a CI/CD stage with a &. E.g., this is an abbreviated version of the .gitlab-ci.yml my project used:

stages:
  - "Lint & Test"

lint:
  stage: "Lint & Test"
  allow_failure: false
  image:
    name: ubuntu:xenial
  script:
    - 'echo "Hello, world."'
  tags:
    - docker-pull-always

Example Project

Example Project Demonstrating the Bug

What is the current bug behavior?

(Note: We are self hosted, however, the bug appears to also be present on GitLab.com.)

Here is a screenshot of what we see, when using something like the above:

Ampersand is doubly escaped

What is the expected correct behavior?

Just "Lint & Test"

We also went with this unusual name b/c before that, we had used more "identifier" like names, such as lint_and_test; however, the same screen will capitalize the name, resulting in "Lint_and_test", which is IMO ugly.

Note that the "pipelines" page listing all pipelines (https://.../{group}/{project}/pipelines) does not exhibit either behavior. (Neither doubly escaping nor randomly capitalizing the first letter.) That is, the pipelines listing page works perfectly!

Relevant logs and/or screenshots

N/A / Above.

Output of checks

(If you are reporting a bug on GitLab.com, write: This bug happens on GitLab.com)

This bug happens on GitLab.com, but was discovered on a self-hosted installation of GitLab.

Results of GitLab environment info

Expand for output related to GitLab environment info 
(For installations with omnibus-gitlab package run and paste the output of:
sudo gitlab-rake gitlab:env:info)


(For installations from source run and paste the output of:
sudo -u git -H bundle exec rake gitlab:env:info RAILS_ENV=production)

Results of GitLab application Check

Expand for output related to the GitLab application check 
(For installations with omnibus-gitlab package run and paste the output of:
sudo gitlab-rake gitlab:check SANITIZE=true)


(For installations from source run and paste the output of:
sudo -u git -H bundle exec rake gitlab:check RAILS_ENV=production SANITIZE=true)


(we will only investigate if the tests are passing)

Possible fixes

(If you can, link to the line of code that might be responsible for the problem)