Redirect /minio to /minio/ when requests come from browsers (#2937)

cmd/generic-handlers.go

@@ -80,15 +80,20 @@ func (h redirectHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	if !strings.EqualFold(os.Getenv("MINIO_BROWSER"), "off") {
 		// Re-direction handled specifically for browsers.
 		if strings.Contains(r.Header.Get("User-Agent"), "Mozilla") && !isRequestSignatureV4(r) {
+			switch r.URL.Path {
+			case "/", "/webrpc", "/login", "/favicon.ico":
 				// '/' is redirected to 'locationPrefix/'
 				// '/webrpc' is redirected to 'locationPrefix/webrpc'
 				// '/login' is redirected to 'locationPrefix/login'
-			switch r.URL.Path {
-			case "/", "/webrpc", "/login", "/favicon.ico":
 				location := h.locationPrefix + r.URL.Path
 				// Redirect to new location.
 				http.Redirect(w, r, location, http.StatusTemporaryRedirect)
 				return
+			case h.locationPrefix:
+				// locationPrefix is redirected to 'locationPrefix/'
+				location := h.locationPrefix + "/"
+				http.Redirect(w, r, location, http.StatusTemporaryRedirect)
+				return
 			}
 		}
 	}