Bug 56557: Fix handling chart sheets

ooxml/XSSF/Streaming/SXSSFWorkbook.cs

@@ -471,7 +471,8 @@ namespace NPOI.XSSF.Streaming
                         zos.PutNextEntry(new ZipEntry(ze.Name));
                         var inputStream = zip.GetInputStream(ze);
                         XSSFSheet xSheet = GetSheetFromZipEntryName(ze.Name);
-                        if (xSheet != null)
+                        // See bug 56557, we should not inject data into the special ChartSheets
+                        if (xSheet != null && !(xSheet is XSSFChartSheet))
                         {
                             SXSSFSheet sxSheet = GetSXSSFSheet(xSheet);
                             var xis = sxSheet.GetWorksheetXMLInputStream();

testcases/ooxml/XSSF/Streaming/TestSXSSFWorkbook.cs

@@ -613,6 +613,20 @@ namespace TestCases.XSSF.Streaming
             ClassicAssert.AreEqual("Test Row 9", s.GetRow(9).GetCell(2).StringCellValue);
         }
 
+        [Test]
+        public void Test56557()
+        {
+            IWorkbook wb = XSSFTestDataSamples.OpenSampleWorkbook("56557.xlsx");
+
+            // Using streaming XSSFWorkbook makes the output file invalid
+            wb = new SXSSFWorkbook((XSSFWorkbook)wb);
+        
+            // Should not throw POIXMLException: java.io.IOException: Unable to parse xml bean when reading back
+            IWorkbook wbBack = XSSFTestDataSamples.WriteOutAndReadBack(wb);
+            ClassicAssert.IsNotNull(wbBack);
+            wbBack.Close();
+        
+            wb.Close();
+        }
     }
-
 }

testcases/ooxml/XSSF/XSSFTestDataSamples.cs

@@ -25,7 +25,9 @@ using NPOI.Util;
 using NPOI.HSSF;
 using TestCases.HSSF;
 using System.Diagnostics;
-using NUnit.Framework;using NUnit.Framework.Legacy;
+using NUnit.Framework;
+using NUnit.Framework.Legacy;
+using NPOI.XSSF.Streaming;
 
 namespace NPOI.XSSF
 {
@@ -86,6 +88,10 @@ namespace NPOI.XSSF
                             sw2.Stop();
                             Debug.WriteLine("XSSFWorkbook parse time: " + sw2.ElapsedMilliseconds + "ms");
                         }
+                        else if (wb is SXSSFWorkbook)
+                        {
+                            result = new SXSSFWorkbook(new XSSFWorkbook(is1));
+                        }
                         else
                         {
                             throw new RuntimeException("Unexpected workbook type ("