From 63c3748900811032ec5dc4e5e42d9745cfc53c4f Mon Sep 17 00:00:00 2001
From: Patrick Linskey <pcl@apache.org>
Date: Tue, 7 Aug 2007 23:47:19 +0000
Subject: [PATCH] OPENJPA-165

git-svn-id: https://svn.apache.org/repos/asf/openjpa/trunk@563702 13f79535-47bb-0310-9956-ffa450edef68
---
 .../query/TestQueryPagination.java            | 81 +++++++++++++++++++
 .../apache/openjpa/persistence/QueryImpl.java |  8 +-
 2 files changed, 88 insertions(+), 1 deletion(-)
 create mode 100644 openjpa-persistence-jdbc/src/test/java/org/apache/openjpa/persistence/query/TestQueryPagination.java

diff --git a/openjpa-persistence-jdbc/src/test/java/org/apache/openjpa/persistence/query/TestQueryPagination.java b/openjpa-persistence-jdbc/src/test/java/org/apache/openjpa/persistence/query/TestQueryPagination.java
new file mode 100644
index 000000000..397680d41
--- /dev/null
+++ b/openjpa-persistence-jdbc/src/test/java/org/apache/openjpa/persistence/query/TestQueryPagination.java
@@ -0,0 +1,81 @@
+/*
+ * 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.    
+ */
+package org.apache.openjpa.persistence.query;
+
+import javax.persistence.EntityManager;
+import javax.persistence.Query;
+
+import org.apache.openjpa.persistence.test.SingleEMFTestCase;
+
+/**
+ * Test that query pagination works properly.
+ */
+public class TestQueryPagination
+    extends SingleEMFTestCase {
+
+    public void setUp() {
+        setUp(SimpleEntity.class, CLEAR_TABLES);
+
+        EntityManager em = emf.createEntityManager();
+        em.getTransaction().begin();
+        em.persist(new SimpleEntity("foo", "bar" + 0));
+        em.persist(new SimpleEntity("foo", "bar" + 1));
+        em.persist(new SimpleEntity("foo", "bar" + 2));
+        em.persist(new SimpleEntity("foo", "bar" + 3));
+        em.persist(new SimpleEntity("foo", "bar" + 4));
+        em.persist(new SimpleEntity("foo", "bar" + 5));
+        em.getTransaction().commit();
+        em.close();
+    }
+
+    public void testFirstThenMax() {
+        helper(true, 2, 3, 3);
+    }
+
+    public void testMaxThenFirst() {
+        helper(false, 2, 3, 3);
+    }
+
+    public void testNoResultsFirstFirst() {
+        helper(true, 10, 3, 0);
+    }
+
+    public void testNoResultsFirstLast() {
+        helper(false, 10, 3, 0);
+    }
+
+    public void testAllResultsFirstFirst() {
+        helper(true, 0, 10, 6);
+    }
+
+    public void testAllResultsFirstLast() {
+        helper(false, 0, 10, 6);
+    }
+
+    private void helper(boolean firstFirst, int first, int max, int expected) {
+        EntityManager em = emf.createEntityManager();
+        Query q = em.createQuery("select e from simple e");
+        if (firstFirst)
+            q.setFirstResult(first).setMaxResults(max);
+        else
+            q.setMaxResults(max).setFirstResult(first);
+        assertEquals(expected, q.getResultList().size());
+        em.close();
+    }
+}
\ No newline at end of file
diff --git a/openjpa-persistence/src/main/java/org/apache/openjpa/persistence/QueryImpl.java b/openjpa-persistence/src/main/java/org/apache/openjpa/persistence/QueryImpl.java
index f59120be4..166c5eae0 100644
--- a/openjpa-persistence/src/main/java/org/apache/openjpa/persistence/QueryImpl.java
+++ b/openjpa-persistence/src/main/java/org/apache/openjpa/persistence/QueryImpl.java
@@ -191,7 +191,13 @@ public class QueryImpl
 
     public OpenJPAQuery setFirstResult(int startPosition) {
         _em.assertNotCloseInvoked();
-        _query.setRange(startPosition, _query.getEndRange());
+        long end;
+        if (_query.getEndRange() == Long.MAX_VALUE)
+            end = Long.MAX_VALUE;
+        else
+            end = startPosition +
+                (_query.getEndRange() - _query.getStartRange());
+        _query.setRange(startPosition, end);
         return this;
     }