Fix for SearchWithRandomIOExceptionsIT#testRandomDirectoryIOExceptions (#101722)

* Updating exception handling to make sure that the DirectoryReader in InternalEngine is properly closed

server/src/internalClusterTest/java/org/elasticsearch/search/basic/SearchWithRandomIOExceptionsIT.java

@@ -41,7 +41,6 @@ public class SearchWithRandomIOExceptionsIT extends ESIntegTestCase {
         return Arrays.asList(MockFSIndexStore.TestPlugin.class);
     }
 
-    @AwaitsFix(bugUrl = "https://github.com/elastic/elasticsearch/issues/99174")
     public void testRandomDirectoryIOExceptions() throws IOException, InterruptedException, ExecutionException {
         String mapping = Strings.toString(
             XContentFactory.jsonBuilder()

server/src/main/java/org/elasticsearch/index/engine/InternalEngine.java

@@ -759,13 +759,11 @@ public class InternalEngine extends Engine {
 
     private ExternalReaderManager createReaderManager(RefreshWarmerListener externalRefreshListener) throws EngineException {
         boolean success = false;
+        ElasticsearchDirectoryReader directoryReader = null;
         ElasticsearchReaderManager internalReaderManager = null;
         try {
             try {
-                final ElasticsearchDirectoryReader directoryReader = ElasticsearchDirectoryReader.wrap(
-                    DirectoryReader.open(indexWriter),
-                    shardId
-                );
+                directoryReader = ElasticsearchDirectoryReader.wrap(DirectoryReader.open(indexWriter), shardId);
                 lastCommittedSegmentInfos = store.readLastCommittedSegmentsInfo();
                 internalReaderManager = createInternalReaderManager(directoryReader);
                 ExternalReaderManager externalReaderManager = new ExternalReaderManager(internalReaderManager, externalRefreshListener);
@@ -782,7 +780,9 @@ public class InternalEngine extends Engine {
             }
         } finally {
             if (success == false) { // release everything we created on a failure
-                IOUtils.closeWhileHandlingException(internalReaderManager, indexWriter);
+                // make sure that we close the directory reader even if the internal reader manager has failed to initialize
+                var reader = internalReaderManager == null ? directoryReader : internalReaderManager;
+                IOUtils.closeWhileHandlingException(reader, indexWriter);
             }
         }
     }