Likely relevant files are
- pkg/web/templates/tree.html
- pkg/web/webui_tree.go
The directory/file being viewed should never be linked. For example, when viewing /repo/tree/branch/dir, repo, tree, and branch should be links, but dir should not. When viewing /repo/tree/branch/path/file/file.go, repo, tree, branch, path, and file should be links, but file.go should not.