Re: Support of csv files with .xls extension

On Thu, 2013-10-24 at 16:34 +0300, Maxim Monastirsky wrote:
> Hi Kohei, great that you responded!
>
> Could you also take a look at 
> https://bugs.freedesktop.org/show_bug.cgi?id=70100. There is a file which is 
> detected by Excel 2010 as 'Excel 2' sheet and LO also sets the excel4 filter, 
> but it fails in isExcel40 function from sc/source/ui/unoobj/exceldetect.cxx 
> because it has a value like in BIFF5.

The key here is that the bug report mentions that this xls file is
generated by a third party software, which may write incorrect BOF ID
for the files it generates.

Ultimately the answer lies here:
http://opengrok.libreoffice.org/xref/core/sc/source/filter/excel/read.cxx#145

Looks like our import filter code itself ignores this BOF ID and lumps
0x0809 toger with the ID's for BIFF2-4.  If that's what the import
filter does, then we should probably do the same in the file format
detection code as well i.e. add 0x0809 to the list of "correct" BOF ID's
for Excel 4.0 format or earlier.

This shouldn't affect detection of more recent Excel file formats, since
those formats use OLE to store workbook and other streams, and we use
that to detect those versions, not the BOF ID's.

As with the earlier bug you cited, this one should be an easy fix as
well, and I believe you already have a fix for this?

Kohei