Cannot comment file in MR, filename contains a semicolon

Summary

From the Merge Request page, it's not possible to comment a file if the filename contains a semicolon.

Steps to reproduce

  • Create a MR with a file named :x.
  • Post a comment on any line of that file.

Example Project

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

What is the current bug behavior?

Nothing happens.

What is the expected correct behavior?

It should create and store the comment.

Relevant logs and/or screenshots

Seen on gitlab.com running GitLab Enterprise Edition 11.3.0-rc2-ee dd29a2b8

It looks like the Frontend successfully posts the comment to https://gitlab.com/gitlab-org/security-products/release/notes?target_id=15822031&target_type=merge_request. The server responds with HTTP 200 but the response body is:

{"commands_changes":null,"valid":false,"errors":{"line_code":["can't be blank","must be a valid line code"]}}

@reprazent