Fix DefaultColumnStyle

OpenXmlFormats/Spreadsheet/Sheet/CT_Cell.cs

@@ -130,7 +130,7 @@ public bool IsSetT()
         }
         public bool IsSetS()
         {
-            return sField != 0;
+            return sField != null && sField != 0;
         }
         public bool IsSetF()
         {

ooxml/XSSF/Model/StylesTable.cs

@@ -462,8 +462,11 @@ public XSSFCellStyle GetStyleAt(int idx)
         {
             int styleXfId = 0;
 
-            if (xfs.Count == 0) //in case there is no default style
+            if (idx < 0 || idx >= xfs.Count)
+            {
+                //BUG-60343
                 return null;
+            }
 
             // 0 is the empty default
             if (xfs[idx].xfId > 0)

ooxml/XSSF/Streaming/GZIPSheetDataWriter.cs

@@ -35,6 +35,14 @@ public GZIPSheetDataWriter(SharedStringsTable sharedStringsTable) : base(sharedS
         {
         }
 
+        /**
+         * @param sharedStringsTable the shared strings table, or null if inline text is used
+         * @param ignoreCellStyle whether to use cell style
+         */
+        public GZIPSheetDataWriter(SharedStringsTable sharedStringsTable, bool ignoreCellStyle) :
+            base(sharedStringsTable, ignoreCellStyle)
+        { }
+
         /**
          * @return temp file to write sheet data
          */
@@ -43,7 +51,7 @@ public override FileInfo CreateTempFile()
         {
             return TempFile.CreateTempFile("poi-sxssf-sheet-xml", ".gz");
         }
-        
+
         protected override Stream DecorateInputStream(Stream fis)
         {
             return new GZipInputStream(fis);