Albert Zaharovits 4eb89a6912
UserRoleMapper non-null groups and metadata (#43836)
This is an odd backport of #41774

UserRoleMapper.UserData is constructed by each realm and it is used to
"match" role mapping expressions that eventually supply the role names
of the principal.

This PR filters out `null` collection values (lists and maps), for the groups
and metadata, which get to take part in the role mapping, in preparation
for using Java 9 collection APIs. It filters them as soon as possible, during
the construction.
2019-07-02 00:10:15 +03:00
..