No data returned in large xls Excel 97-2003 worksheet

[CalypsoSys]

I have a very large Excep that is read

calling ExcelReaderFactory.CreateReader(stream) works but when I then call reader.Read() no data is returned

Cannot attach file, but it is available on (318 MB)

https://vondavon.com/exceldatareader/vehicles_xls.xls

[andersnm]

Hi,

Interesting, thank you. The Excep contains a "V4 Macro Sheet", but ExcelDataReader doesn't recognize that and skips it. I can read it after changing certain sheet type checks (and optimizing the cyclic sector check):

--- a/src/ExcelDataReader/Core/BinaryFormat/XlsWorkbook.cs
+++ b/src/ExcelDataReader/Core/BinaryFormat/XlsWorkbook.cs
@@ -173,7 +173,7 @@ namespace ExcelDataReader.Core.BinaryFormat
                         InterfaceHdr = hdr;
                         break;
                     case XlsBiffBoundSheet sheet:
-                        if (sheet.Type != XlsBiffBoundSheet.SheetType.Worksheet)
+                        if (sheet.Type != XlsBiffBoundSheet.SheetType.Worksheet && sheet.Type != XlsBiffBoundSheet.SheetType.MacroSheet)
                             break;
                         Sheets.Add(sheet);
                         break;


--- a/src/ExcelDataReader/Core/BinaryFormat/XlsWorksheet.cs
+++ b/src/ExcelDataReader/Core/BinaryFormat/XlsWorksheet.cs
@@ -435,7 +435,7 @@ namespace ExcelDataReader.Core.BinaryFormat
             using (var biffStream = new XlsBiffStream(Stream, (int)DataOffset, Workbook.BiffVersion, null, Workbook.SecretKey, Workbook.Encryption))
             {
                 // Check the expected BOF record was found in the BIFF stream
-                if (biffStream.BiffVersion == 0 || biffStream.BiffType != BIFFTYPE.Worksheet)
+                if (biffStream.BiffVersion == 0 || (biffStream.BiffType != BIFFTYPE.Worksheet && biffStream.BiffType != BIFFTYPE.v4MacroSheet))
                     return;
 
                 XlsBiffHeaderFooterString header = null;


--- a/src/ExcelDataReader/Core/CompoundFormat/CompoundDocument.cs
+++ b/src/ExcelDataReader/Core/CompoundFormat/CompoundDocument.cs
@@ -75,12 +75,19 @@ namespace ExcelDataReader.Core.CompoundFormat
         internal List<uint> GetSectorChain(uint sector, List<uint> sectorTable)
         {
             List<uint> chain = new List<uint>();
+#if !NET20
+            HashSet<uint> uniq = new HashSet<uint>();
+#endif
             while (sector != (uint)FATMARKERS.FAT_EndOfChain)
             {
                 chain.Add(sector);
                 sector = GetNextSector(sector, sectorTable);
 
+#if !NET20
+                if (!uniq.Add(sector))
+#else
                 if (chain.Contains(sector))
+#endif
                 {
                     throw new CompoundDocumentException(Errors.ErrorCyclicSectorChain);
                 }

[CalypsoSys]

thanks!

I will build locally and apply fix. Will this get rolled into a distributed release or would you recommend forking and merge with changes with main branches?

[andersnm]

Hi, I'm sure this will be fixed at some point, but I cannot give an ETA. I'd like to familiarize myself with these "Macro Sheets" a bit more - f.ex can we assume to treat them as regular sheets? Maybe they should always be last? Until then, to progress I recommend to patch the latest develop branch and use that. The latest prerelease nuget was built from the latest develop branch.

[CalypsoSys]

thank you very much - this library is great, in my tests so much faster than the alternatives for read-only operations and easy to use!