The cloned reference for merged cells did not create a new collection,

so deletes cascaded to the original.
Reported by: huri@users.sourceforge.net
PR:  22720


git-svn-id: https://svn.apache.org/repos/asf/jakarta/poi/branches/REL_2_BRANCH@353451 13f79535-47bb-0310-9956-ffa450edef68

src/java/org/apache/poi/hssf/record/MergeCellsRecord.java

@@ -326,7 +326,8 @@ public class MergeCellsRecord
     public Object clone() {
         MergeCellsRecord rec = new MergeCellsRecord();
         rec.field_1_num_areas = field_1_num_areas;
-        rec.field_2_regions = field_2_regions;
+        rec.field_2_regions = new ArrayList();
+        rec.field_2_regions.addAll(field_2_regions);
         return rec;
     }
 }

src/testcases/org/apache/poi/hssf/record/TestMergeCellsRecord.java

@@ -0,0 +1,79 @@
+
+/* ====================================================================
+ * The Apache Software License, Version 1.1
+ *
+ * Copyright (c) 2003, 2003 The Apache Software Foundation.  All rights
+ * reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * 3. The end-user documentation included with the redistribution,
+ *    if any, must include the following acknowledgment:
+ *       "This product includes software developed by the
+ *        Apache Software Foundation (http://www.apache.org/)."
+ *    Alternately, this acknowledgment may appear in the software itself,
+ *    if and wherever such third-party acknowledgments normally appear.
+ *
+ * 4. The names "Apache" and "Apache Software Foundation" and
+ *    "Apache POI" must not be used to endorse or promote products
+ *    derived from this software without prior written permission. For
+ *    written permission, please contact apache@apache.org.
+ *
+ * 5. Products derived from this software may not be called "Apache",
+ *    "Apache POI", nor may "Apache" appear in their name, without
+ *    prior written permission of the Apache Software Foundation.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
+ * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+ * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ * ====================================================================
+ *
+ * This software consists of voluntary contributions made by many
+ * individuals on behalf of the Apache Software Foundation.  For more
+ * information on the Apache Software Foundation, please see
+ * <http://www.apache.org/>.
+ */
+package org.apache.poi.hssf.record;
+
+import junit.framework.TestCase;
+
+/**
+ * Make sure the merge cells record behaves
+ * @author Danny Mui (dmui at apache dot org)
+ *
+ */
+public class TestMergeCellsRecord extends TestCase {
+   
+   /**
+    * Make sure when a clone is called, we actually clone it.
+    * @throws Exception
+    */
+   public void testCloneReferences() throws Exception {
+      MergeCellsRecord merge = new MergeCellsRecord();
+      merge.addArea(0, (short)0, 1, (short)2);
+      MergeCellsRecord clone = (MergeCellsRecord)merge.clone();
+      
+      assertNotSame("Merged and cloned objects are the same", merge, clone);
+      merge.removeAreaAt(0);
+      assertNotNull("Clone's item not removed", clone.getAreaAt(0));
+   }
+}

src/testcases/org/apache/poi/hssf/usermodel/TestBugs.java

@@ -54,16 +54,16 @@
 
 package org.apache.poi.hssf.usermodel;
 
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.FileOutputStream;
-import java.io.ByteArrayInputStream;
-import java.io.ByteArrayOutputStream;
-import java.io.IOException;
-import java.util.Date;
 
 import junit.framework.TestCase;
 
+import org.apache.poi.hssf.util.Region;
+
 
 
 /**
@@ -407,6 +407,37 @@ extends TestCase {
         HSSFCell cell = row.getCell((short)0);
         System.out.println(cell.getStringCellValue());
     }
+    
+    /**
+     * Merged regions were being removed from the parent in cloned sheets
+     * @throws Exception
+     */
+    public void test22720() throws Exception {
+       HSSFWorkbook workBook = new HSSFWorkbook();
+       workBook.createSheet("TEST");       
+       HSSFSheet template = workBook.getSheetAt(0);
+       
+       template.addMergedRegion(new Region(0, (short)0, 1, (short)2));
+       template.addMergedRegion(new Region(1, (short)0, 2, (short)2));
+       
+       HSSFSheet clone = workBook.cloneSheet(0);
+       int originalMerged = template.getNumMergedRegions();
+       assertEquals("2 merged regions", 2, originalMerged);
+
+//        remove merged regions from clone
+       for (int i=template.getNumMergedRegions()-1; i>=0; i--) {
+         clone.removeMergedRegion(i);
+       }
+
+      assertEquals("Original Sheet's Merged Regions were removed", originalMerged, template.getNumMergedRegions());
+//        check if template's merged regions are OK
+       if (template.getNumMergedRegions()>0) {
+          // fetch the first merged region...EXCEPTION OCCURS HERE
+          template.getMergedRegionAt(0);
+       }       
+       //make sure we dont exception
+       
+    }
 }