From 79c13d62d3d4b23d5df9a224056952ab11df6f56 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20H=C3=B8ydahl?= <janhoy@apache.org>
Date: Tue, 6 Aug 2019 15:33:08 +0200
Subject: [PATCH] Added check for explicit empty line response from Zookeeper

---
 .../handler/admin/ZookeeperStatusHandler.java |  2 +-
 .../admin/ZookeeperStatusHandlerTest.java     | 19 +++++++++++++++++++
 2 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/solr/core/src/java/org/apache/solr/handler/admin/ZookeeperStatusHandler.java b/solr/core/src/java/org/apache/solr/handler/admin/ZookeeperStatusHandler.java
index 7a36889a5f8..04caefb1022 100644
--- a/solr/core/src/java/org/apache/solr/handler/admin/ZookeeperStatusHandler.java
+++ b/solr/core/src/java/org/apache/solr/handler/admin/ZookeeperStatusHandler.java
@@ -255,7 +255,7 @@ public class ZookeeperStatusHandler extends RequestHandlerBase {
    * @throws SolrException if validation fails
    */
   protected boolean validateZkRawResponse(List<String> response, String zkHostPort, String fourLetterWordCommand) {
-    if (response == null || response.isEmpty()) {
+    if (response == null || response.isEmpty() || (response.size() == 1 && response.get(0).isBlank())) {
       throw new SolrException(SolrException.ErrorCode.SERVER_ERROR, "Empty response from Zookeeper " + zkHostPort);
     }
     if (response.size() == 1 && response.get(0).contains("not in the whitelist")) {
diff --git a/solr/core/src/test/org/apache/solr/handler/admin/ZookeeperStatusHandlerTest.java b/solr/core/src/test/org/apache/solr/handler/admin/ZookeeperStatusHandlerTest.java
index f66db4b41d8..ad2f22e40e0 100644
--- a/solr/core/src/test/org/apache/solr/handler/admin/ZookeeperStatusHandlerTest.java
+++ b/solr/core/src/test/org/apache/solr/handler/admin/ZookeeperStatusHandlerTest.java
@@ -21,6 +21,7 @@ import java.io.IOException;
 import java.lang.invoke.MethodHandles;
 import java.net.URL;
 import java.util.Arrays;
+import java.util.Collections;
 import java.util.List;
 import java.util.Map;
 import java.util.concurrent.ExecutionException;
@@ -33,6 +34,7 @@ import org.apache.solr.client.solrj.impl.HttpSolrClient;
 import org.apache.solr.client.solrj.request.GenericSolrRequest;
 import org.apache.solr.client.solrj.response.DelegationTokenResponse;
 import org.apache.solr.cloud.SolrCloudTestCase;
+import org.apache.solr.common.SolrException;
 import org.apache.solr.common.params.ModifiableSolrParams;
 import org.apache.solr.common.util.NamedList;
 import org.junit.After;
@@ -41,6 +43,7 @@ import org.junit.BeforeClass;
 import org.junit.Test;
 import org.mockito.Answers;
 import org.mockito.ArgumentMatchers;
+import org.mockito.invocation.InvocationOnMock;
 import org.noggit.JSONUtil;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -49,6 +52,7 @@ import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.ArgumentMatchers.anyString;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
+import static org.mockito.Mockito.withSettings;
 
 public class ZookeeperStatusHandlerTest extends SolrCloudTestCase {
   private static final Logger log = LoggerFactory.getLogger(MethodHandles.lookup().lookupClass());
@@ -148,4 +152,19 @@ public class ZookeeperStatusHandlerTest extends SolrCloudTestCase {
         "  \"status\":\"yellow\"}";
     assertEquals(expected, JSONUtil.toJSON(mockStatus));
   }
+
+  @Test(expected = SolrException.class)
+  public void validateNotWhitelisted() {
+    assumeWorkingMockito();
+    ZookeeperStatusHandler zkStatusHandler = mock(ZookeeperStatusHandler.class, withSettings().defaultAnswer(InvocationOnMock::callRealMethod));
+    zkStatusHandler.validateZkRawResponse(Collections.singletonList("mntr is not executed because it is not in the whitelist."),
+        "zoo1:2181", "mntr");
+  }
+
+  @Test(expected = SolrException.class)
+  public void validateEmptyResponse() {
+    assumeWorkingMockito();
+    ZookeeperStatusHandler zkStatusHandler = mock(ZookeeperStatusHandler.class, withSettings().defaultAnswer(InvocationOnMock::callRealMethod));
+    zkStatusHandler.validateZkRawResponse(Collections.emptyList(), "zoo1:2181", "mntr");
+  }
 }
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