Incorrect handling of sanitized help URLs
Summary
- https://gitlab.com/help/ci/quick_start/README.md works
- https://gitlab.com/help%2Fci/quick_start/README.md displays 404
- https://gitlab.com/help/ci%2Fquick_start/README.md has broken links (mentioned in #14872 (closed))
- https://gitlab.com/help/ci/quick_start%2FREADME.md has broken links and broken images
- https://gitlab.com/help/ci%2Fquick_start%2FREADME.md displays 404
- https://gitlab.com/help/ci/quick_start/README.md/ has broken links and broken images
- https://gitlab.com/help/ci/quick_start/README.md%2F displays 404
Expected behavior
In my opinion, all but the first URL should either display 404 or redirect to the first URL.