User profiles: Make sure all users have a displayname defined

[tobifjellner]

As far as I know, nowadays the system doesn't allow a user to clear out the displayname, but some profiles on wp-org don't have any displayname defined.

In some views this makes it harder to see the username of someone who has posted or commented.

I suggest that someone, as a one-time action, should search for all user profiles that have an empty displayname, and set it to the username.

[dd32]

For reference, on WordPress.org there's over 600,000 users who don't have a display_name set (out of 17+ million - user ID's aren't secret).

While it looks like it's the earlier users, there's a registered user as recently as 2019-07-23 who has a blank display name, although that just looks like because the HTML junk added to their Name field probably sanitized out to a blank string.

[coffee2code]

In some views this makes it harder to see the username of someone who has posted or commented.

@tobifjellner: Can you provide an example of this happening in a view?

[tobifjellner]

@coffee2code I will, next time I stumble upon one such profile. (whenever I see one, I usually ask someone to fix that profile.)

[dd32]

In 10238:

Add a MU plugin to fill in users empty display_name fields when possible.

Some users on WordPress.org have empty display_name fields due to bugs in sanitization of user profile saving.

Fixes #5416.
See #4644.