Bugfix: Make util/request-url handle empty query string

Empty query strings would make request-url insert a trailing ?
in the url for no reason. While not strictly invalid, it's a bit ugly.
Empty query strings are added by ring.mock.request/request when you pass
in an empty map for parameters.

This fixes that by checking that the query string is not empty before
adding the ?.

Author: rutchkiwi

ring-core/src/ring/util/request.clj

@@ -10,7 +10,7 @@
        "://"
        (get-in request [:headers "host"])
        (:uri request)
-       (when-let [query (:query-string request)]
+       (when-let [query (not-empty (:query-string request))]
          (str "?" query))))
 
 (defn content-type

ring-core/test/ring/util/test/request.clj

@@ -17,6 +17,11 @@
   (is (= (request-url {:scheme :https
                        :uri "/index.html"
                        :headers {"host" "www.example.com"}})
+         "https://www.example.com/index.html"))
+  (is (= (request-url {:scheme :https
+                       :uri "/index.html"
+                       :headers {"host" "www.example.com"}
+                       :query-string ""})
          "https://www.example.com/index.html")))
 
 (deftest test-content-type