GEODE-5274: Null check for closing CacheClientProxy (#2014)

Co-authored-by: bijukunjummen <biju.kunjummen@gmail.com>

geode-core/src/main/java/org/apache/geode/internal/i18n/LocalizedStrings.java

@@ -7716,6 +7716,11 @@ public class LocalizedStrings {
   public static final StringId LuceneIndexCreation_INDEX_CANNOT_BE_CREATED_DUE_TO_PROFILE_VIOLATION =
       new StringId(6667,
           "Lucene index {0} cannot be created because its parameters are incompatible with another Lucene index");
+
+  public static final StringId cq_CACHE_CLIENT_PROXY_IS_NULL =
+      new StringId(6668,
+          "No Cache Client Proxy found while executing CQ.");
+
   /** Testing strings, messageId 90000-99999 **/
 
   /**

geode-cq/src/main/java/org/apache/geode/cache/query/internal/cq/CqServiceImpl.java

@@ -284,8 +284,10 @@ public synchronized ServerCQ executeCq(String cqName, String queryString, int cq
           if (emptyRegionsMap != null && emptyRegionsMap.containsKey(cQuery.getBaseRegionName())) {
             regionDataPolicy = 0;
           }
+
+          CacheClientProxy proxy = getCacheClientProxy(clientProxyId, ccn);
           ccn.updateMapOfEmptyRegions(
-              ccn.getClientProxy(clientProxyId, true).getRegionsWithEmptyDataPolicy(),
+              proxy.getRegionsWithEmptyDataPolicy(),
               cQuery.getBaseRegionName(), regionDataPolicy);
         }
       } catch (CqException cqe) {
@@ -307,6 +309,15 @@ public synchronized ServerCQ executeCq(String cqName, String queryString, int cq
     return cQuery;
   }
 
+  protected CacheClientProxy getCacheClientProxy(ClientProxyMembershipID clientProxyId,
+      CacheClientNotifier ccn) throws CqException {
+    CacheClientProxy proxy = ccn.getClientProxy(clientProxyId, true);
+    if (proxy == null) {
+      throw new CqException(LocalizedStrings.cq_CACHE_CLIENT_PROXY_IS_NULL.toLocalizedString());
+    }
+    return proxy;
+  }
+
   @Override
   public void resumeCQ(int cqState, ServerCQ cQuery) {
     // Initialize the state of CQ.

geode-cq/src/test/java/org/apache/geode/cache/query/internal/cq/CqServiceImplJUnitTest.java

@@ -0,0 +1,63 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more contributor license
+ * agreements. See the NOTICE file distributed with this work for additional information regarding
+ * copyright ownership. The ASF licenses this file to You under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the License. You may obtain a
+ * copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License
+ * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
+ * or implied. See the License for the specific language governing permissions and limitations under
+ * the License.
+ */
+package org.apache.geode.cache.query.internal.cq;
+
+import static org.junit.Assert.fail;
+import static org.mockito.Mockito.doNothing;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+import org.junit.Test;
+import org.junit.experimental.categories.Category;
+
+import org.apache.geode.CancelCriterion;
+import org.apache.geode.cache.query.CqException;
+import org.apache.geode.distributed.DistributedSystem;
+import org.apache.geode.internal.cache.InternalCache;
+import org.apache.geode.internal.cache.tier.sockets.CacheClientNotifier;
+import org.apache.geode.internal.cache.tier.sockets.ClientProxyMembershipID;
+import org.apache.geode.internal.i18n.LocalizedStrings;
+import org.apache.geode.test.junit.categories.UnitTest;
+
+@Category(UnitTest.class)
+public class CqServiceImplJUnitTest {
+
+  @Test
+  public void closedCacheClientProxyInExecuteCqShouldThrowCQException() {
+    InternalCache cache = mock(InternalCache.class);
+    CancelCriterion cancelCriterion = mock(CancelCriterion.class);
+    DistributedSystem distributedSystem = mock(DistributedSystem.class);
+    doNothing().when(cancelCriterion).checkCancelInProgress(null);
+    when(cache.getCancelCriterion()).thenReturn(cancelCriterion);
+    when(cache.getDistributedSystem()).thenReturn(distributedSystem);
+
+
+    ClientProxyMembershipID clientProxyMembershipID = mock(ClientProxyMembershipID.class);
+    CacheClientNotifier cacheClientNotifier = mock(CacheClientNotifier.class);
+    when(cacheClientNotifier.getClientProxy(clientProxyMembershipID, true)).thenReturn(null);
+
+    CqServiceImpl cqService = new CqServiceImpl(cache);
+    try {
+      cqService.getCacheClientProxy(clientProxyMembershipID, cacheClientNotifier);
+      fail();
+    } catch (Exception ex) {
+      if (!(ex instanceof CqException && ex.getMessage()
+          .contains(LocalizedStrings.cq_CACHE_CLIENT_PROXY_IS_NULL.toLocalizedString()))) {
+        fail();
+      }
+    }
+
+  }
+}