Ruby Spreadsheet, NaN is a Float but it doesn't adhere to any operations so doing multiplication on a NaN will make the script explode

nan.patch

--- orig/worksheet.rb   2011-04-18 10:26:50.000000000 +0200
+++ patched/worksheet.rb        2011-04-18 10:27:23.000000000 +0200
@@ -89,7 +89,7 @@
   def need_number? cell
     if cell.is_a?(Numeric) && cell.abs > 0x1fffffff
       true
-    elsif cell.is_a?(Float)
+    elsif cell.is_a?(Float) and not cell.nan?
       higher = cell * 100
       if higher == higher.to_i
         need_number? higher.to_i

test.patch

--- a/test/excel/writer/worksheet.rb
+++ b/test/excel/writer/worksheet.rb
@@ -14,6 +14,7 @@ class TestWorksheet < Test::Unit::TestCase
     assert_equal false, sheet.need_number?(114.55)
     assert_equal false, sheet.need_number?(0.1)
     assert_equal false, sheet.need_number?(0.01)
+    assert_equal false, sheet.need_number?(0 / 0.0) # NaN
     assert_equal true, sheet.need_number?(0.001)
     assert_equal true, sheet.need_number?(10000000.0)
   end

test.rb

# Without the patch this file will not be written out because of the NaN.
# Infinity will be written out, it'll look odd but it'll be written out in the Excel file.
# So I suggest the patch so that NaN is written out the same as INF, even if neither really ought to be written to a file to begin with.

require 'rubygems'
require 'spreadsheet'

wb = Spreadsheet::Workbook.new
ws = wb.create_worksheet(:name => 'test')

ws[0,1] = 1 / 0.0 # INF
ws[0,2] = 'test'
ws[0,3] = 0 / 0.0 # NaN

wb.write('test.xls')

Thanks for this patch!

Can you please supply us with some testcode for the according test file?

Best
Zeno