Bug 17222: Workbook corruption when using sheet.addRow()

git-svn-id: https://svn.apache.org/repos/asf/jakarta/poi/trunk@353009 13f79535-47bb-0310-9956-ffa450edef68

src/java/org/apache/poi/hssf/model/Sheet.java

@@ -995,6 +995,10 @@ public class Sheet implements Model
             d.setFirstRow(row.getRowNumber());
         }
         //IndexRecord index = null;
+         //If the row exists remove it, so that any cells attached to the row are removed
+         RowRecord existingRow = rows.getRow(row.getRowNumber());
+         if (existingRow != null)
+           rows.removeRow(existingRow);
 
         rows.insertRow(row);