From 5184c4b7ef2419d7e874a783aef1382ffa2a5760 Mon Sep 17 00:00:00 2001
From: Jens Langhammer <jens.langhammer@beryju.org>
Date: Mon, 14 Sep 2020 18:40:26 +0200
Subject: [PATCH] flows: fix FlowNonApplicableException and EmptyFlowException
 leading to infinite spinners

---
 passbook/core/templates/error/embedded.html | 25 +++++++++++++++++++++
 passbook/flows/exceptions.py                |  4 ++--
 passbook/flows/views.py                     |  5 ++++-
 passbook/lib/views.py                       | 10 ++++-----
 4 files changed, 36 insertions(+), 8 deletions(-)
 create mode 100644 passbook/core/templates/error/embedded.html

diff --git a/passbook/core/templates/error/embedded.html b/passbook/core/templates/error/embedded.html
new file mode 100644
index 000000000..ddd0986e8
--- /dev/null
+++ b/passbook/core/templates/error/embedded.html
@@ -0,0 +1,25 @@
+{# Template used by bad_request_message within flows #}
+{% extends 'login/base.html' %}
+
+{% load static %}
+{% load i18n %}
+{% load passbook_utils %}
+
+{% block title %}
+{% trans card_title %}
+{% endblock %}
+
+{% block card_title %}
+{% trans card_title %}
+{% endblock %}
+
+{% block card %}
+<form method="POST" class="pf-c-form">
+    {% if message %}
+    <h3>{% trans message %}</h3>
+    {% endif %}
+    {% if 'back' in request.GET %}
+    <a href="{% back %}" class="btn btn-primary btn-block btn-lg">{% trans 'Back' %}</a>
+    {% endif %}
+</form>
+{% endblock %}
diff --git a/passbook/flows/exceptions.py b/passbook/flows/exceptions.py
index 4bcf6f854..47072264c 100644
--- a/passbook/flows/exceptions.py
+++ b/passbook/flows/exceptions.py
@@ -2,8 +2,8 @@
 
 
 class FlowNonApplicableException(BaseException):
-    """Exception raised when a Flow does not apply to a user."""
+    """Flow does not apply to current user (denied by policy)."""
 
 
 class EmptyFlowException(BaseException):
-    """Exception raised when a Flow Plan is empty"""
+    """Flow has no stages."""
diff --git a/passbook/flows/views.py b/passbook/flows/views.py
index 5553291c3..75769a267 100644
--- a/passbook/flows/views.py
+++ b/passbook/flows/views.py
@@ -54,7 +54,10 @@ class FlowExecutorView(View):
                 LOGGER.debug("f(exec): Redirecting to next on fail")
                 return redirect(self.request.GET.get(NEXT_ARG_NAME))
         message = exc.__doc__ if exc.__doc__ else str(exc)
-        return bad_request_message(self.request, message)
+        return to_stage_response(
+            self.request,
+            bad_request_message(self.request, message, template="error/embedded.html"),
+        )
 
     def dispatch(self, request: HttpRequest, flow_slug: str) -> HttpResponse:
         # Early check if theres an active Plan for the current session
diff --git a/passbook/lib/views.py b/passbook/lib/views.py
index a82ec9e84..2fe5281e2 100644
--- a/passbook/lib/views.py
+++ b/passbook/lib/views.py
@@ -27,12 +27,12 @@ class CreateAssignPermView(CreateView):
 
 
 def bad_request_message(
-    request: HttpRequest, message: str, title="Bad Request"
+    request: HttpRequest,
+    message: str,
+    title="Bad Request",
+    template="error/generic.html",
 ) -> TemplateResponse:
     """Return generic error page with message, with status code set to 400"""
     return TemplateResponse(
-        request,
-        "error/generic.html",
-        {"message": message, "card_title": _(title)},
-        status=400,
+        request, template, {"message": message, "card_title": _(title)}, status=400,
     )