Adjust WAC inheritance algorithm to rely on acl:default

Author: acoburn

auth/webac/src/main/java/org/trellisldp/webac/WebAcService.java

@@ -246,7 +246,8 @@ private AuthorizedModes getAuthz(final IRI identifier, final IRI agent) {
 
     private AuthorizedModes getModesFor(final IRI identifier, final IRI agent) {
         return getNearestResource(identifier).map(resource -> {
-            final Authorizations authorizations = getAllAuthorizationsFor(resource, false);
+            final Authorizations authorizations = getAllAuthorizationsFor(resource,
+                    !identifier.equals(resource.getIdentifier()));
             return new AuthorizedModes(authorizations.getIdentifier(), authorizations.stream()
                     .filter(agentFilter(agent)).flatMap(auth -> auth.getMode().stream()).collect(toSet()));
         }).orElseGet(() -> new AuthorizedModes(root, emptySet()));

auth/webac/src/test/java/org/trellisldp/webac/WebAcServiceTest.java

@@ -600,6 +600,7 @@ void testInheritRoot() {
         when(mockSession.getAgent()).thenReturn(agentIRI);
 
         assertAll("Test default ACL writability",
+                checkCannotWrite(nonexistentIRI),
                 checkCannotWrite(resourceIRI),
                 checkCanWrite(childIRI),
                 checkCannotWrite(parentIRI),