[bug-66687] Combination of XSSF and SXSSF may result in invalid files. Thanks to Martin Schloemer. This closes #814

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1925881 13f79535-47bb-0310-9956-ffa450edef68

poi-ooxml/src/main/java/org/apache/poi/xssf/usermodel/XSSFSheet.java

@@ -3926,7 +3926,15 @@ public class XSSFSheet extends POIXMLDocumentPart implements Sheet, OoxmlSheetEx
             if(minCell != Integer.MAX_VALUE) {
                 cellRangeAddress = new CellRangeAddress(getFirstRowNum(), getLastRowNum(), minCell, maxCell);
             }
+        } else {
+        	// sort columns
+            for(Map.Entry<Integer, XSSFRow> entry : _rows.entrySet()) {
+                XSSFRow row = entry.getValue();
+                // sorting happens in XSSFRow.fixupCTCells
+                row.onDocumentWrite();
+            }
         }
+
         if (cellRangeAddress != null) {
             if (worksheet.isSetDimension()) {
                 worksheet.getDimension().setRef(cellRangeAddress.formatAsString());

poi-ooxml/src/test/java/org/apache/poi/xssf/streaming/TestOutOfOrderColumns.java

@@ -0,0 +1,122 @@
+/*
+ *  ====================================================================
+ *    Licensed to the Apache Software Foundation (ASF) under one or more
+ *    contributor license agreements.  See the NOTICE file distributed with
+ *    this work for additional information regarding copyright ownership.
+ *    The ASF licenses this file to You under the Apache License, Version 2.0
+ *    (the "License"); you may not use this file except in compliance with
+ *    the License.  You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *    Unless required by applicable law or agreed to in writing, software
+ *    distributed under the License is distributed on an "AS IS" BASIS,
+ *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *    See the License for the specific language governing permissions and
+ *    limitations under the License.
+ * ====================================================================
+ */
+
+package org.apache.poi.xssf.streaming;
+
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import java.io.IOException;
+import java.io.InputStream;
+
+import org.apache.commons.io.output.UnsynchronizedByteArrayOutputStream;
+import org.apache.poi.ss.usermodel.Row;
+import org.apache.poi.ss.usermodel.Sheet;
+import org.apache.poi.xssf.usermodel.XSSFSheet;
+import org.apache.poi.xssf.usermodel.XSSFWorkbook;
+import org.junit.jupiter.api.Test;
+
+/**
+ * Test creates cells in reverse column order in XSSF and SXSSF and expects
+ * saved files to have fixed the order.
+ * 
+ * This is necessary because if columns in the saved file are out of order
+ * Excel will show a repair dialog when opening the file and removing data.
+ */
+public final class TestOutOfOrderColumns {
+
+    @Test
+    void outOfOrderColumnsXSSF() throws IOException {
+        try (
+                XSSFWorkbook wb = new XSSFWorkbook();
+                UnsynchronizedByteArrayOutputStream bos = UnsynchronizedByteArrayOutputStream.builder().get()
+        ) {
+            XSSFSheet sheet = wb.createSheet();
+            
+            Row row = sheet.createRow(0);
+            // create cells in reverse order
+            row.createCell(1).setCellValue("def");
+            row.createCell(0).setCellValue("abc");
+
+            wb.write(bos);
+
+            validateOrder(bos.toInputStream());
+        }
+    }
+
+    @Test
+    void outOfOrderColumnsSXSSF() throws IOException {
+        try (
+                SXSSFWorkbook wb = new SXSSFWorkbook();
+                UnsynchronizedByteArrayOutputStream bos = UnsynchronizedByteArrayOutputStream.builder().get()
+        ) {
+            Sheet sheet = wb.createSheet();
+            
+            Row row = sheet.createRow(0);
+            // create cells in reverse order
+            row.createCell(1).setCellValue("xyz");
+            row.createCell(0).setCellValue("uvw");
+            
+            wb.write(bos);
+
+            validateOrder(bos.toInputStream());
+        }
+    }
+
+    @Test
+    /** this is the problematic case, as XSSF column sorting is skipped when saving with SXSSF. */
+    void mixOfXSSFAndSXSSF() throws IOException {
+        try (
+                XSSFWorkbook wb = new XSSFWorkbook();
+                UnsynchronizedByteArrayOutputStream bos = UnsynchronizedByteArrayOutputStream.builder().get()
+        ) {
+            XSSFSheet sheet = wb.createSheet();
+            
+            Row row1 = sheet.createRow(0);
+            // create cells in reverse order
+            row1.createCell(1).setCellValue("def");
+            row1.createCell(0).setCellValue("abc");
+
+            try (SXSSFWorkbook sxssfWorkbook = new SXSSFWorkbook(wb)) {
+                Sheet sSheet = sxssfWorkbook.getSheetAt(0);
+                Row row2 = sSheet.createRow(1);
+                // create cells in reverse order
+                row2.createCell(1).setCellValue("xyz");
+                row2.createCell(0).setCellValue("uvw");
+                
+                sxssfWorkbook.write(bos);
+
+                validateOrder(bos.toInputStream());
+            }
+        }
+    }
+
+    private void validateOrder(InputStream is) throws IOException {
+        // test if saved cells are in order
+        try (XSSFWorkbook xssfWorkbook = new XSSFWorkbook(is)) {
+            XSSFSheet xssfSheet = xssfWorkbook.getSheetAt(0);
+            
+            Row resultRow = xssfSheet.getRow(0);
+            // POI doesn't show stored order because _cells TreeMap sorts it automatically.
+            // The only way to test is to compare the xml.
+            String s = resultRow.toString();
+            assertTrue(s.matches("(?s).*A1.*B1.*"), "unexpected order: " + s);
+        }
+    }
+
+}