FPSpreadsheet and external: SIGSEGV
lazarus / 5-Lazarus Extra Components

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tjstew · 2009-12-03 18:39

Hi ... Following useful earlier help on my attempts at using the
fpspreadsheet package, may I post a tantalizing one.  When I try to
open the Excel file in the attached ZIP using fpspreadsheet (this XLS
file was generated by a GIS system), I get the error message External:
SIGSEGV.

I have seen posts on this message which I frankly don't understand. 
But the tantalizing issue is that if I copy all the data in the file
to a new spreadsheet and save it, my program works fine ... no errors.

Can someone explain what the error message is telling me in this
context?
Thanks
Theo

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felipemdc · 2009-12-12 22:22

SIGSEGV = Segmentation Fault, which is a UNIX error code, which is
equivalent to the Pascal Access Violation, which means that you are
accessing a pointer to a forbitten location. You should run your
application using GDB or the Lazarus debugger to find the stack trace
of the crash, and other information to find the fix.

In the end it comes down to either the OLE Document reader or the
Excel reader, usually the OLE reader, because OLE is such a complex
format, with so many options, it's probable that the application that
wrote the file is using some uncommon option not supported, and when
you copy and save again it doesn't use them. But it could be the same
for the Excel reader, although much less likely.

Also, make sure that you are using the latest svn fpspreadsheet.

So, then you can either try to fix the problem yourself, which you can
achieve by using a software to byte compare the problematic file and
the good working file to see which options are being used differently
and how they crash the library and submit a patch with a fix, or post
a bug report with the working file, the not working file, the
backtrace and the code of your application.

If you want to fix it yourself I can then post more information on the
subject.

thanks,