Cannot open file in MR, filename contains a semicolon

Summary

From the Merge Request page, it's not possible to open a file by clicking on View file @xyz if the filename contains a semicolon.

Steps to reproduce

• Submit a MR with a file named :x.
• Open the MR in GitLab.
• Click on the View file button.

Example Project

See https://gitlab.com/gitlab-org/security-products/release/blob/ae2f385e6c1d21dbe19457d763a74c127f1db4ac/:x but MR has been updated.

What is the current bug behavior?

The browser is being redirected to a broken link. The HTTP 500 error page shows up.

What is the expected correct behavior?

It should open/redirect to the file at the given commit (last commit of the MR).

Relevant logs and/or screenshots

Seen on production running GitLab Enterprise Edition 11.3.0-rc2-ee gitlab-ce@dd29a2b8f453e30ac052614875cd2bb6e1333449.

https://sentry.gitlap.com/gitlab/gitlabcom/issues/496833/?query=is:unresolved

cc @reprazent