Merge "Sort changes from Lucene by updated descending"

gerrit-lucene/src/main/java/com/google/gerrit/lucene/LuceneChangeIndex.java

diff --git a/gerrit-lucene/src/main/java/com/google/gerrit/lucene/LuceneChangeIndex.java b/gerrit-lucene/src/main/java/com/google/gerrit/lucene/LuceneChangeIndex.java
index f2a9ab1..f331bcc 100644
--- a/gerrit-lucene/src/main/java/com/google/gerrit/lucene/LuceneChangeIndex.java
+++ b/gerrit-lucene/src/main/java/com/google/gerrit/lucene/LuceneChangeIndex.java
@@ -63,6 +63,8 @@
 import org.apache.lucene.search.Query;
 import org.apache.lucene.search.ScoreDoc;
 import org.apache.lucene.search.SearcherManager;
+import org.apache.lucene.search.Sort;
+import org.apache.lucene.search.SortField;
 import org.apache.lucene.search.TermQuery;
 import org.apache.lucene.search.TopDocs;
 import org.apache.lucene.util.BytesRef;
@@ -333,13 +335,18 @@
     @Override
     public ResultSet<ChangeData> read() throws OrmException {
       IndexSearcher[] searchers = new IndexSearcher[indexes.size()];
+      Sort sort = new Sort(
+          new SortField(
+              ChangeField.UPDATED.getName(),
+              SortField.Type.INT,
+              true /* descending */));
       try {
         TopDocs[] hits = new TopDocs[indexes.size()];
         for (int i = 0; i < indexes.size(); i++) {
           searchers[i] = indexes.get(i).acquire();
-          hits[i] = searchers[i].search(query, LIMIT);
+          hits[i] = searchers[i].search(query, LIMIT, sort);
         }
-        TopDocs docs = TopDocs.merge(null, LIMIT, hits);
+        TopDocs docs = TopDocs.merge(sort, LIMIT, hits);
 
         List<ChangeData> result =
             Lists.newArrayListWithCapacity(docs.scoreDocs.length);