diff --git a/lucene/src/test/org/apache/lucene/index/TestOptimizeForever.java b/lucene/src/test/org/apache/lucene/index/TestOptimizeForever.java
new file mode 100644
index 00000000000..90c515e2f82
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+++ b/lucene/src/test/org/apache/lucene/index/TestOptimizeForever.java
@@ -0,0 +1,106 @@
+package org.apache.lucene.index;
+
+/**
+ * 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.
+ */
+
+import java.io.IOException;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.atomic.AtomicInteger;
+
+import org.apache.lucene.analysis.MockAnalyzer;
+import org.apache.lucene.store.Directory;
+import org.apache.lucene.util.LineFileDocs;
+import org.apache.lucene.util.LuceneTestCase;
+import org.apache.lucene.util._TestUtil;
+
+
+public class TestOptimizeForever extends LuceneTestCase {
+
+  // Just counts how many merges are done for optimize
+  private static class MyIndexWriter extends IndexWriter {
+
+    AtomicInteger optimizeMergeCount = new AtomicInteger();
+    private boolean first;
+
+    public MyIndexWriter(Directory dir, IndexWriterConfig conf) throws Exception {
+      super(dir, conf);
+    }
+
+    @Override
+    public void merge(MergePolicy.OneMerge merge) throws CorruptIndexException, IOException {
+      if (merge.optimize && (first || merge.segments.size() == 1)) {
+        first = false;
+        if (VERBOSE) {
+          System.out.println("TEST: optimized merge");
+        }
+        optimizeMergeCount.incrementAndGet();
+      }
+      super.merge(merge);
+    }
+  }
+
+  public void test() throws Exception {
+    final Directory d = newDirectory();
+    final MyIndexWriter w = new MyIndexWriter(d, newIndexWriterConfig(TEST_VERSION_CURRENT, new MockAnalyzer(random)));
+    w.setInfoStream(VERBOSE ? System.out : null);
+
+    // Try to make an index that requires optimizing:
+    w.getConfig().setMaxBufferedDocs(_TestUtil.nextInt(random, 2, 11));
+    final int numStartDocs = atLeast(20);
+    final LineFileDocs docs = new LineFileDocs(random);
+    for(int docIDX=0;docIDX<numStartDocs;docIDX++) {
+      w.addDocument(docs.nextDoc());
+    }
+    MergePolicy mp = w.getConfig().getMergePolicy();
+    final int mergeAtOnce = 1+w.segmentInfos.size();
+    if (mp instanceof TieredMergePolicy) {
+      ((TieredMergePolicy) mp).setMaxMergeAtOnce(mergeAtOnce);
+    } else if (mp instanceof LogMergePolicy) {
+      ((LogMergePolicy) mp).setMergeFactor(mergeAtOnce);
+    } else {
+      // skip test
+      w.close();
+      d.close();
+      return;
+    }
+
+    final AtomicBoolean doStop = new AtomicBoolean();
+    w.getConfig().setMaxBufferedDocs(2);
+    Thread t = new Thread() {
+      @Override
+      public void run() {
+        try {
+          while (!doStop.get()) {
+            w.updateDocument(new Term("docid", "" + random.nextInt(numStartDocs)),
+                             docs.nextDoc());
+            // Force deletes to apply
+            w.getReader().close();
+          }
+        } catch (Throwable t) {
+          throw new RuntimeException(t);
+        }
+      }
+      };
+    t.start();
+    w.optimize();
+    doStop.set(true);
+    t.join();
+    assertTrue("optimize count is " + w.optimizeMergeCount.get(), w.optimizeMergeCount.get() <= 1);
+    w.close();
+    d.close();
+  }
+}