After upgrading the client to 3.3.0 on Windows 7, we have a 'Migrated filter' in the certificate filters list. This is able to be removed in the settings, but restarting the client makes it reappear. This is a continuation of bug 3590, comment #20.
The main problem here is that if a client customization is done registry keys are stored into local machine and the migration of filter mechanism tries to remove the old filter but fails due to no access. To handle this problem we should use a new key to indicate that a filter has been migrated.
Fix committed in rev 25615. Tester should use an old version of client customizer that creates a custom smartcard filter in local machine part of registry, this can be manually added into place for the test. Then upgrade the client to verify that filter get migrated.
I don't think this implementation is minimal - I think we can get rid of the new parameter SMARTCARD_FILTER_MIGRATED. Patch will follow.
Attached patch for minimal approach applied in commit r26049.
Works great.