Browser's previous and next buttons don't work on Merge Requests sub-pages

Summary

The Merge Requests sub-pages buttons (Discussion, Commits, Pipelines, Builds, Changes) make the browser's url change in the address bar, but the browser's history is not updated as expected when a page change occurs.

Using the browser's previous an next buttons then doesn't work.

Steps to reproduce

• Go to any Merge Request on a GitLab installation, and switch between the sub-pages.
• Notice the url in the browser's address bar changes.
• Notice the browser's previous and next buttons do not reflect the url changes.

Expected behavior

The browser's previous and next buttons should be updated when the browser's url changes.

GitLab environment info

The issue is present on the latest version at this time of this report (8.12.1-ee gitlab-ce@8a575a57eb72ef661be1a65bca010e80106aa492)