Evaluate authorization for requests that carry no principal

[GGraziadei]

Summary

SimpleACLAuthorizer.permit and SupervisorSimpleACLAuthorizer.permit dereferenced context.principal() directly, so a request that carries no principal ended in a NullPointerException instead of an authorization decision. Over the UI this surfaced as HTTP 500 rather than 403.

Both now read the principal defensively, the way SimpleWhitelistAuthorizer and DRPCSimpleACLAuthorizer already do. IPrincipalToLocal.toLocal(Principal) is null-safe already.

Behaviour

No decision logic changes. A request without a principal simply follows the rules that were already written: it matches no admin, supervisor or nimbus entry; it keeps the allow-all behaviour when nimbus.users and nimbus.groups are both empty; and it is denied as soon as a list is configured or a topology-level ACL applies.

Testing

• mvn -pl storm-client test -DskipITs — 661 tests, 0 failures
• mvn -pl storm-server test -DskipITs — 490 tests, 0 failures
• New cases cover a principal-less request against configured lists, against empty lists, and against a topology operation, for both authorizers.