better link for flip, maybe now, a little hack

code/app.py

@@ -373,8 +373,14 @@ def file_direct(name, token, filename):
     if not allow_direct:
         return "-1", 403
     token = get_direct_token(share, filename)
-    url = url_for('download_direct', name = name, token = token, filename = filename )
-    return  url, 200
+    # url_for returns extra level of /../path if proxying with nginx
+    return  "/".join((
+        app.config['PUBLIC_URL'],
+        'direct',
+        name,
+        token,
+        path2url(filename)
+    )), 200
 
 
 @app.route('/file/ls/<name>/<token>', methods=['GET'])