SEARCH-2202 Fix NPE issues and add unit test for BoundedDeque.

search-services/alfresco-solrclient-lib/src/main/java/org/alfresco/solr/client/AclChangeSets.java

@@ -43,7 +43,7 @@ public class AclChangeSets
     
     AclChangeSets(List<AclChangeSet> aclChangeSets, Long maxChangeSetCommitTime, Long maxChangeSetId)
     {
-        this.aclChangeSets = new ArrayList<>(aclChangeSets);
+        this.aclChangeSets = (aclChangeSets == null ? null : new ArrayList<>(aclChangeSets));
         this.maxChangeSetCommitTime = maxChangeSetCommitTime;
         this.maxChangeSetId = maxChangeSetId;
     }

search-services/alfresco-solrclient-lib/src/main/java/org/alfresco/solr/client/AclReaders.java

@@ -51,8 +51,8 @@ public class AclReaders
     public AclReaders(long id, List<String> readers, List<String> denied, long aclChangeSetId, String tenantDomain)
     {
         this.id = id;
-        this.readers = new ArrayList<>(readers);
-        this.denied = new ArrayList<>(denied);
+        this.readers = (readers == null ? null : new ArrayList<>(readers));
+        this.denied = (denied == null ? null : new ArrayList<>(denied));
         this.aclChangeSetId = aclChangeSetId;
         this.tenantDomain = tenantDomain;
     }

search-services/alfresco-solrclient-lib/src/test/java/org/alfresco/solr/BoundedDequeTest.java

@@ -0,0 +1,57 @@
+/*
+ * #%L
+ * Alfresco Solr Client
+ * %%
+ * Copyright (C) 2005 - 2016 Alfresco Software Limited
+ * %%
+ * This file is part of the Alfresco software.
+ * If the software was purchased under a paid Alfresco license, the terms of
+ * the paid license agreement will prevail.  Otherwise, the software is
+ * provided under the following open source license terms:
+ *
+ * Alfresco is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Alfresco is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with Alfresco. If not, see <http://www.gnu.org/licenses/>.
+ * #L%
+ */
+
+package org.alfresco.solr;
+
+import static java.util.Arrays.asList;
+
+import static org.junit.Assert.assertEquals;
+
+import java.util.ArrayList;
+import java.util.concurrent.LinkedBlockingDeque;
+
+import org.junit.Test;
+
+/** Unit tests for the {@link BoundedDeque}. */
+public class BoundedDequeTest
+{
+	/** Check that earlier entries are removed from the BoundedDeque. */
+	@Test
+	public void testBoundedness()
+	{
+		// Create a BoundedDeque with size two.
+		BoundedDeque<Object> boundedDeque = new BoundedDeque<>(2);
+
+		// Add three things.
+		boundedDeque.add("A");
+		boundedDeque.add("B");
+		boundedDeque.add("C");
+
+		// Check that the latest two are still there.
+		LinkedBlockingDeque<Object> actual = boundedDeque.getDeque();
+		assertEquals("Unexpected entries in BoundedDeque.", asList("C", "B"), new ArrayList(actual));
+	}
+}