MONDRIAN: RoalpNativeSet must return copies from cache because the re…

…turned sets are modified in later steps

[git-p4: depot-paths = "//open/mondrian/": change = 4456]

src/main/mondrian/rolap/RolapNativeSet.java

@@ -10,7 +10,6 @@
 
 import java.util.ArrayList;
 import java.util.Arrays;
-import java.util.Collections;
 import java.util.List;
 
 import mondrian.olap.Exp;
@@ -129,7 +128,7 @@ public Object execute() {
                     TupleEvent e = new TupleEvent(this, tr);
                     listener.foundInCache(e);
                 }
-                return result;
+                return copy(result);
             }
 
             // execute sql and store the result
@@ -138,12 +137,20 @@ public Object execute() {
                 listener.excutingSql(e);
             }
             result = tr.readTuples(schemaReader.getDataSource());
-            result = Collections.unmodifiableList(result);
             cache.put(key, result);
-            return result;
+            return copy(result);
         }
 
 
+        /**
+         * returns a copy of the result because its modified
+         */
+        private List copy(List list) {
+            List copy = new ArrayList();
+            copy.addAll(list);
+            return copy;
+        }
+
         private void addLevel(TupleReader tr, CrossJoinArg arg) {
             RolapLevel level = arg.getLevel();
             Hierarchy hierarchy = level.getHierarchy();

testsrc/main/mondrian/rolap/NonEmptyTest.java

@@ -46,14 +46,28 @@ public class NonEmptyTest extends FoodMartTestCase {
     private static Logger logger = Logger.getLogger(NonEmptyTest.class);
     SqlConstraintFactory scf = SqlConstraintFactory.instance();
 
+    /** 
+     * checks that crossjoin returns a modifiable copy from cache 
+     * because its modified during sort
+     */
+    public void testResultIsModifyableCopy() {
+        checkNative(3, 3, "select {[Measures].[Store Sales]} on columns,"
+                + "  NON EMPTY Order(" 
+                + "        CrossJoin([Customers].[All Customers].[USA].children, [Promotions].[Promotion Name].Members), "
+                + "        [Measures].[Store Sales]) ON ROWS"
+                + " from [Sales] where ("
+                + "  [Store].[All Stores].[USA].[CA].[San Francisco].[Store 14],"
+                + "  [Time].[1997].[Q1].[1])");
+    }
+
     /** check that top count is executed native unless disabled */
     public void testNativeTopCount() {
         if (!MondrianProperties.instance().EnableNativeTopCount.get())
             return;
         checkNative(3, 3, "select {[Measures].[Store Sales]} on columns,"
                 + "  NON EMPTY TopCount(" 
                 + "        CrossJoin([Customers].[All Customers].[USA].children, [Promotions].[Promotion Name].Members), "
-                + "        10, [Measures].[Store Sales]) ON ROWS"
+                + "        3, [Measures].[Store Sales]) ON ROWS"
                 + " from [Sales] where ("
                 + "  [Store].[All Stores].[USA].[CA].[San Francisco].[Store 14],"
                 + "  [Time].[1997].[Q1].[1])");