Why does env['PATH_INFO'] get overwritten?

[joshuajaco]

We are having issues in our tests where we use last_request.env['PATH_INFO'] to get the requested URL to validate the response against our JSON specification. This breaks when trying to test the unauthenticated case, because warden overwrites env['PATH_INFO'] to /unauthenticated. Why is that?
Relevant code is:

warden/lib/warden/manager.rb

Line 139 in 5b3cbd5

env["PATH_INFO"] = "/#{options[:action]}"