order was undefined in case of duplicate sort keys, this could lead to incorrect results (documents appearing twice in the result set, other documents missing) if there were more than 100 matches.

PR:31241


git-svn-id: https://svn.apache.org/repos/asf/lucene/java/trunk@150523 13f79535-47bb-0310-9956-ffa450edef68

src/java/org/apache/lucene/search/FieldSortedHitQueue.java

@@ -95,6 +95,9 @@ extends PriorityQueue {
       c = (fields[i].reverse) ? comparators[i].compare (docB, docA)
                               : comparators[i].compare (docA, docB);
     }
+    // avoid random sort order that could lead to duplicates (bug #31241):
+    if (c == 0)
+      return docA.doc > docB.doc;
     return c > 0;
   }