[bug-69021] add guard around cast

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1917779 13f79535-47bb-0310-9956-ffa450edef68

poi/src/main/java/org/apache/poi/hssf/model/InternalWorkbook.java

@@ -1071,13 +1071,16 @@ record = lSST.createExtSSTRecord(sstPos + offset);
  *
  * Include in it ant code that modifies the workbook record stream and affects its size.
  */
- public void preSerialize(){
+ public void preSerialize() {
  // Ensure we have enough tab IDs
  // Can be a few short if new sheets were added
- if(records.getTabpos() > 0) {
- TabIdRecord tir = ( TabIdRecord ) records.get(records.getTabpos());
- if(tir.getTabIdSize() < boundsheets.size()) {
- fixTabIdRecord();
+ if (records.getTabpos() > 0) {
+ Record rec = records.get(records.getTabpos());
+ if (rec instanceof TabIdRecord) {
+ TabIdRecord tir = ( TabIdRecord ) rec;
+ if(tir.getTabIdSize() < boundsheets.size()) {
+ fixTabIdRecord();
+ }
  }
  }
  }

poi/src/test/java/org/apache/poi/hssf/usermodel/TestHSSFSheetShiftRows.java

@@ -18,11 +18,32 @@ Licensed to the Apache Software Foundation (ASF) under one or more
 package org.apache.poi.hssf.usermodel;
 
 import org.apache.poi.hssf.HSSFITestDataProvider;
+import org.apache.poi.hssf.HSSFTestDataSamples;
 import org.apache.poi.ss.usermodel.BaseTestSheetShiftRows;
+import org.apache.poi.ss.usermodel.Row;
+import org.apache.poi.ss.usermodel.Sheet;
+import org.junit.jupiter.api.Test;
+
+import java.io.IOException;
+
+import static org.junit.jupiter.api.Assertions.assertNotNull;
 
 final class TestHSSFSheetShiftRows extends BaseTestSheetShiftRows {
 
  public TestHSSFSheetShiftRows() {
  super(HSSFITestDataProvider.instance);
  }
+
+ @Test
+ public void testBug69021() throws IOException {
+ try (HSSFWorkbook workbook = HSSFTestDataSamples.openSampleWorkbook("bug69021.xls")) {
+ Sheet sheet = workbook.getSheetAt(0);
+ int rowIndex = 2;
+ sheet.shiftRows(rowIndex, sheet.getLastRowNum(), 1);
+ Row row = sheet.createRow(rowIndex);
+ row.createCell(0).setCellValue("switch");
+ HSSFWorkbook wbBack = HSSFTestDataSamples.writeOutAndReadBack(workbook);
+ assertNotNull(wbBack);
+ }
+ }
 }