For the new-comment-notification feature we decided to put sessionStorage in a MemoryStarage wrapper, so that even sessionStorage was disabled, your reply would be recovered if you clicked the notification (as it doesn't reload the page), however the MemoryStorage was not passed to the VE surface, so this fails.
Note that the MemoryStorage wrapper was designed to protect against an edge case of someone using the new-comment-notification with sessionStorage disabled or broken, which is likely a very rare edge case, so it is unlikely anyone has been affected by this bug yet.
- Open a reply in the Test section at the bottom of this page: https://en.wikipedia.beta.wmflabs.org/w/index.php?title=Talk:Main_Page&oldid=546972#Test_5
- You should see the "Show 1 new comment" button
- Write something in the reply widget
- Open the console and clear your sessionStorage using sessionStorage.clear()
- Click the "Show 1 new comment" button
- Your draft reply is recovered
- It gets stuck on "loading"