Character encoding set only when charset in content-type header

@@ -68,12 +68,14 @@
        first
        string/trim)))
 
+(defn- get-charset [content-type]
+  (->> content-type
+       (re-find #"charset=(.+);?")
+       (second)))
+
 (defn- set-character-encoding [response content-type]
-  (.setCharacterEncoding
-   response
-   (-> (re-find #"charset=(.+);?" content-type)
-       second
-       (or "utf-8"))))
+  (when-let [charset (get-charset content-type)]
+    (.setCharacterEncoding response charset)))
 
 (defn set-headers
   "Update a HttpServletResponse with a map of headers."

@@ -88,7 +88,7 @@
         (run-servlet handler request response)
         (is (= (@response :status) 200))
         (is (= (@response :content-type) "text/plain"))
-        (is (= (@response :character-encoding) "utf-8"))
+        (is (= (@response :character-encoding) "UTF-8"))
         (is (= (get-in @response [:headers "X-Server"]) "Bar"))))
     (testing "response with character encoding"
       (letfn [(handler [r]