Ingo Fabbri authored Jul 22, 2021 and Oliver Bartsch committed Nov 22, 2021

The backend usergroup compare view requires to fetch the
group data of the groups to compare. Since this operation
depends on a user array, UserInformationService creates
such dummy user.

Since #93233 the dummy user array also contains a workspace
id `-99`.

To successfully overcome workspace access-checks, set
the admin-flag for this fake-user. Use workspace uid 0,
to avoid any database operations on workspace access
checks. Workspace 0 additionally prevents the log-message,
which led to the exception message described at #93894.

Resolves: #93894
Related: #93233
Releases: master, 11.5
Change-Id: Ieb5da95082cb6dfd5c030fbd04d735863d587510
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/70056

Tested-by: core-ci <typo3@b13.com>
Tested-by: Jochen <rothjochen@gmail.com>
Tested-by: Nikita Hovratov <nikita.h@live.de>
Tested-by: Oliver Bartsch <bo@cedev.de>
Reviewed-by: Jochen <rothjochen@gmail.com>
Reviewed-by: Nikita Hovratov <nikita.h@live.de>
Reviewed-by: Oliver Bartsch <bo@cedev.de>