[PATCH setup] Add new option --chown-admin

[Jon Turney]

On 06/07/2022 08:14, Christian Franke wrote:
> If an installer is run elevated, the installed files will be typically 
> owned by the local administrator (or in some cases SYSTEM or 
> TrustedInstaller) instead of the current user. This is not the case for 
> a Cygwin "All Users" installation. The files are then not protected from 

... instead the files are owned by the user running setup?

> accidental changes by this user.
> 
> The attached patch adds an experimental --chown-admin option which 
> allows (new) installations owned by local administrator user and group.

Thanks for the patch, but...

> A drawback is that files generated by postinstall scripts are still 
> owned by current user + "None" group. It should be possible to fix this 
> with some perpetual preremove+postinstall scripts.
> 
> I also don't know whether this may break some postinstall scripts.
> 
> BTW: 'nt_sec.setDefaultSecurity (isAdmin)' is never called with 
> 'isAdmin==true' as 'root_scope' is always 0.

root_scope is set later, by the "Install For" option on the "Select Root 
Install Directory" page.

To me, this looks like a (very long standing) bug that we shouldn't be 
calling setAdminGroup() here, but after root_scope has been set.