1. Click on 'Mark as resolved' on a topic without a summary.
2. Without adding anything, click 'Update summary'.
3. Two notifications will be sent - one 'Topic was summarized" and another one "The topic was resolved". The timestamps will be different.
4. Go to 'View history' and click on the entry that says "[username] created topic summary on [date]" - The page does not have any permanent link (or any other info to a user).

e.g. https://en.wikipedia.beta.wmflabs.org/w/index.php?title=Topic:T093qrgbdmah9e97&topicsummary_revId=t1zi3g1wrdjko0ob&action=view-topic-summary

It looks very confusing to a user to find the 'created summary' entry empty - it might look like the info was lost and the functionality broken.