Authorization offline_access needs prompt

Author: rohe

src/oidcservice/oidc/authorization.py

@@ -104,12 +104,15 @@ def oidc_pre_construct(self, request_args=None, **kwargs):
         return request_args, post_args
 
     def oidc_post_construct(self, req, **kwargs):
-
         if 'openid' in req['scope']:
             _response_type = req['response_type'][0]
             if 'id_token' in _response_type or 'code' in _response_type:
                 self.store_nonce2state(req['nonce'], req['state'])
 
+        if 'offline_access' in req['scope']:
+            if 'prompt' not in req:
+                req['prompt'] = 'consent'
+
         try:
             _request_method = kwargs['request_param']
         except KeyError: