Merge remote-tracking branch 'origin/raph'

components/availability/AvailabilityForm.js

@@ -25,6 +25,8 @@ export default function AvailabilityForm({ publisherId, existingItems, inline, o
     indexUrl: "/cart/availabilities"
   };
 
+  existingitems = existingitems || [];
+
   const [editMode, setEditMode] = useState(existingItems.length > 0);
   const [publisher, setPublisher] = useState({ id: publisherId });
   const [day, setDay] = useState(new Date(date));