==== What is the problem?
When WWT shows a revision popup for a revision whose edit summary is hidden, it shows the loading animation indefinitely.
It should probably handle it similarly to hidden contributor names (as implemented in T232215).
Instead of the edit summary, it could show something like: "~~(edit summary removed)~~" instead.
==== Steps to reproduce problem
1. https://es.wikipedia.org/wiki/Hispanidad?oldid=100161751
2. Launch WWT
3. In the first paragraph, click any word in the sentence starting "Para muchos es...".
**Expected behavior:** Revision popup displays all information apart from the hidden edit summary.
**Observed behavior:** Revision popup loading animation displays indefinitely.
==== Environment
I have reproduce this in WWT version 0.11. Probably existed earlier.
It existed before the work in T240707, but the bug has a bigger impact after that work, as now none of the information in the revision popup will show.