test inequality of HistoryEntry instances

Author: vladak

opengrok-indexer/src/test/java/org/opengrok/indexer/history/HistoryEntryTest.java

@@ -18,7 +18,7 @@
  */
 
 /*
- * Copyright (c) 2008, 2021, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2008, 2023, Oracle and/or its affiliates. All rights reserved.
  */
 package org.opengrok.indexer.history;
 
@@ -292,6 +292,22 @@ public void testEquals() {
         assertEquals(e, instance);
     }
 
+    @Test
+    public void testNotEqualsRevision() {
+        HistoryEntry e = new HistoryEntry(historyRevision + "0", historyDisplayRevision, historyDate,
+                historyAuthor, historyMessage, true, null);
+        assertNotSame(e, instance);
+        assertNotEquals(e, instance);
+    }
+
+    @Test
+    public void testNotEqualsDisplayRevision() {
+        HistoryEntry e = new HistoryEntry(historyRevision, historyDisplayRevision + "0", historyDate,
+                historyAuthor, historyMessage, true, null);
+        assertNotSame(e, instance);
+        assertNotEquals(e, instance);
+    }
+
     @Test
     public void testEqualsWithFilesInstance() {
         HistoryEntry e = new HistoryEntry(historyRevision, historyDisplayRevision, historyDate,