Tested on a local instance running CheckUser and other extensions.
Followed the following steps:
* Gave myself suppressor rights
* Suppressed a test edit so that the edit had the following restrictions:
{F35274252}
* Removed suppressor rights from myself
* Ran a check on the IP used (in this case a localhost IP as I'm running a local instance)
* Scrolled down to the edit and saw:
{F35274253}
The edit summary is correctly suppressed, but not the username. A CU could be running a check on a wide range or IP from running a check on a different account. They can then, without knowing the username, see the suppressed performer username.
To fix Lines 1931 down in SpecialCheckUser.php need to work out if the username / performer is suppressed for that edit.
This also affects Special:Investigate as shown below (same edit used):
{F35274293}
{F35274292}
Summary:
- For edits
-- SpecialCheckUser - awaiting deployment
-- SpecialInvestigate - not fixed
-- CU API - not fixed
- logged actions can not be fixed fully without a schema change