Can you check if this happened at a specific revision? I just tried it now, and I see the entire text highlighted, given credit to your username as have written 100% of the page.

(Edit: I also "walked back" 4-5 previous revisions, and I could still see basically the same popup detail. I couldn't spot one where the IP was hidden.)

Is there a specific revision where the missing details happened?

I can reproduce if I click on (so far) any part of the article except the links (which Danny added).

With the console open, I get: WhoWroteThat failed to fetch data for revision with ID 955696280

I believe it is defaulting to the earliest, not deleted revision (955696280). WWT then does an API request of the form action=compare&fromrev=955696280&torelative=prev, except the previously revision is deleted, so the API returns an exception.

For example, you will see an exception if you go to https://en.wikipedia.org/w/api.php?action=compare&fromrev=955696280&torelative=prev.

Presumably the popup Danny is seeing is just what the popup defaults to when it has no data.

Perhaps its because I'm not an admin, and so cannot access the information from the deleted revisions?
This occurs for me at the top revision, https://en.wikipedia.org/w/index.php?title=James_Alexander_Chiles&oldid=956782636

In T252860#6140596, @DannyS712 wrote:

Perhaps its because I'm not an admin, and so cannot access the information from the deleted revisions?

Yes, I think user rights are significant. I think the extension is making the API call as whatever user you are logged in as at the time (or anon if not logged in).

We definitely rely on user rights when we show (and not show) the information when a revision is suppressed or deleted, by feature (not bug) so it sounds reasonable that if the revision was deleted, you'd get a popup with hidden details.

The fact that the percentages may not match is actually an interesting problem. In the example you give, @DannyS712 , you are basically the sole (or almost sole) author, so it's pretty obvious what the attribution should be, but when the revision we're looking at from a piece of text is suppressed, MW itself doesn't give us information about that user, which means we can't really use it to properly connect it to any other information on the data we're getting from WWT.

That's a bit of a mix between intended consequences (we want to make sure we don't expose deleted revisions, for privacy and security) and unintendede consequences (this "breaks" the data "link" between MW info and WWT info.)

I could see those revisions; I am not an admin, but I think I have some rights because of the Anti Harassment Tools work on blocks, which explains that (that's also likely why I couldn't see the bug you initially reported)

So given all the above ,unless I'm missing something this looks like it's not something we can (or should?) fix? Am I missing something? I want to verify, otherwise we can close the ticket?

@Mooeypoo: Your (WMF) account is in the Staff global group. This contains the rights required to view deleted content.

Yeah I'd consider the missing username/edit summary as a bug, for sure. The absence of a username is what's causing the discrepancy with the percentages, is my guess. We should also get rid of that stray ().

Note that WikiWho doesn't see the deleted content either, so in either case the percentages are going to be wrong. They should at least be consistent for privileged/unprivileged accounts, though.