"At" symbol (@) URL encoding is inconsistent when navigating a directory structure

Issue Summary

When you have a folder names with an At Symbol (@), clicking the first level of such a named folder does not properly URL encode the folder name as "%40"

Steps to Reproduce

1. Deploy the latest Bitbucket Server code base
2. Create a Repo with multiple levels of folders names with the At symbols, such as the scructure: @dir1/@dir2/@dir3
3. Make sure to place a file into each of the folder levels so that you can navigate to each specific level in the UI.
4. Push the repo to the Bitbucket server
5. Navigate in the Bitbucket UI to the new repo.
6. Click the @dir1 folder name, and check the URL on the Location bar. It should still contain the explicit '@' symbol, rather than it being URL encode to "%40"
7. Next click @dir2, and you should see that now both @dir1 and @dir2 appear in the URL as "%40dir1/%40dir2", properly URL encoded.
8. Clicking @dir3 will also have the same correct result.
9. Next, navitgate back to the top level of the repo, using the link for the repo name at the top of the page.
10. Finally, click the @dir1 link again, and you will once again see the incorrectly encoded URL with @dir1, rather than "%40dir1".

Details of this are visible in the attached .MOV file.

Expected Results

All At symbols (@) in the right hand side of a URL should be encoded as "%40" at all times. Not just after there are 2 such references to the resource portion of the URL.

Actual Results

First directory click makes the Location: http://127.0.0.1:8080/projects/REID/repos/at-testing/browse/@dir1

If this is copy-pasted elsewhere, it does not parse correctly and a 404 or error is returned to the referrer.

Workaround

The user much know that the URL is invalid and has to be manually encoded properly, if they harvest the presented URL from the system.