External refunds: Processing should not affect order's state if order is canceled

src/pretix/control/templates/pretixcontrol/order/refund_process.html

@@ -25,6 +25,13 @@
                 <strong>{{ pending }}</strong>. The order total is <strong>{{ total }}</strong>.
             {% endblocktrans %}
         </p>
+        {% if order.status != "c" and order.positions.count > 0 %}
+            <p>
+                {% blocktrans trimmed %}
+                    Since the order is already canceled, this will not affect its state.
+                {% endblocktrans %}
+            </p>
+        {% else %}
             <p>
                 {% blocktrans trimmed with amount=refund.amount|money:request.event.currency method=refund.payment_provider.verbose_name %}
                     What should happen to the ticket order?
@@ -41,6 +48,7 @@
                     {% trans "Cancel the order irrevocably." %}
                 </label>
             </div>
+        {% endif %}
         <div class="form-group submit-group">
             <a class="btn btn-default btn-lg"
                     href="{% url "control:event.order" event=request.event.slug organizer=request.event.organizer.slug code=order.code %}">

src/pretix/control/views/orders.py

@@ -566,7 +566,8 @@ class OrderRefundProcess(OrderView):
         if self.refund.state == OrderRefund.REFUND_STATE_EXTERNAL:
             self.refund.done(user=self.request.user)
 
-            if self.request.POST.get("action") == "r" and (self.order.status != Order.STATUS_CANCELED and self.order.positions.exists()):
+            if self.order.status != Order.STATUS_CANCELED and self.order.positions.exists():
+                if self.request.POST.get("action") == "r":
                     mark_order_refunded(self.order, user=self.request.user)
                 elif not (self.order.status == Order.STATUS_PAID and self.order.pending_sum <= 0):
                     self.order.status = Order.STATUS_PENDING