Inconsistent parsing of path equal to "/"

[jathd]

When the path of a URI is just "/", the parser sometimes returns "/", and sometimes returns an empty path:

(parse-uri "/")      ; => NIL, NIL, NIL, NIL, NIL, NIL, NIL
(parse-uri "//a/")   ; => NIL, NIL, "a", NIL, "/", NIL, NIL
(parse-uri "foo:/")  ; => "foo", NIL, NIL, NIL, NIL, NIL

The path should be "/" in all the above cases.