500 error when viewing blame or history of file with newline in filename

Summary

When viewing the blame or history of a file with a newline character in its filename, the user will receive of 500 error page.

Steps to reproduce

1. On one's own machine, create a repository that contains a file with a newline character in its filename.
2. Upload the repository to Gitlab.
3. Select the file with the newline character from the project page.
4. Select either the "Blame" or "History" view for that file.
5. You should see a 500 error page.

Example Project

https://gitlab.com/jessehall3/filenames_with_newlines

What is the current bug behavior?

The user see a 500 error page.

What is the expected correct behavior?

The user should see the blame or history views.

Output of checks

This bug happens on GitLab.com

Possible fixes

After addressing a very similar issue in a previous merge request, I can see the issue is with the routing constraints on L37 in config/routes/repository.rb.

I plan on submitting a merge request for this issue shortly after completing this issue.