HTTP 404 with breadcrumb in source annotate mode

==== Description: ====
When navigating through the source of a project and annotate mode is turned on, clicking on any of the breadcrumb links ( except the root one ) produces an HTTP 404.

==== Reproduction: ====

• Navigate to the source of a file in a project, assuming that this file sits in a nested directory within the project
• Turn on annotate mode by clicking "annotate" near the top of the source file viewer
• Click on any of the breadcrumb links, you should get an HTTP 404

==== Additional ====
The root breadcrumb is unaffected, only nested ones are affected. I've included some pics to help out.