ResultSet.absolute did not always work with large result sets.

h2/src/main/org/h2/result/ResultDiskBuffer.java

@@ -138,6 +138,7 @@ class ResultDiskBuffer implements ResultExternal {
             }
         } else {
             mainTape.pos = FileStore.HEADER_LENGTH;
+            mainTape.buffer = new ObjectArray();
         }
     }
 

h2/src/test/org/h2/test/jdbc/TestResultSet.java

@@ -42,6 +42,7 @@ public class TestResultSet extends TestBase {
 
         stat = conn.createStatement();
         
+        testAbsolute();
         testFetchSize();
         testOwnUpdates();
         testFindColumn();
@@ -69,6 +70,20 @@ public class TestResultSet extends TestBase {
 
     }
     
+    private void testAbsolute() throws Exception {
+        // stat.execute("SET MAX_MEMORY_ROWS 90");
+        stat.execute("CREATE TABLE TEST(ID INT PRIMARY KEY)");
+        // there was a problem when more than MAX_MEMORY_ROWS where in the result set
+        stat.execute("INSERT INTO TEST SELECT X FROM SYSTEM_RANGE(1, 200)");
+        Statement s2 = conn.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_READ_ONLY);
+        ResultSet rs = s2.executeQuery("SELECT * FROM TEST ORDER BY ID");
+        for (int i = 100; i > 0; i--) {
+            rs.absolute(i);
+            assertEquals(i, rs.getInt(1));
+        }
+        stat.execute("DROP TABLE TEST");
+    }
+    
     private void testFetchSize() throws Exception {
         if (!config.networked || config.memory) {
             return;