A better way to determine if an RK record is sufficient, or if we nee…

…d a NUMBER record

Fixes: http://rubyforge.org/tracker/index.php?func=detail&aid=24119&group_id=678&atid=2677

lib/spreadsheet/excel/writer/worksheet.rb

@@ -86,9 +86,19 @@ def name
     unicode_string @worksheet.name
   end
   def need_number? cell
-    (cell.is_a?(Numeric) && cell.abs > 0x1fffffff) \
-      || (cell.is_a?(Float) \
-          && !/^[\000\001]\000{3}/.match([cell * 100].pack(EIGHT_BYTE_DOUBLE)))
+    if cell.is_a?(Numeric) && cell.abs > 0x1fffffff
+      true
+    elsif cell.is_a?(Float)
+      higher = cell * 100
+      if higher == higher.to_i
+        need_number? higher.to_i
+      else
+        test1, test2 = [cell * 100].pack(EIGHT_BYTE_DOUBLE).unpack('V2')
+        test1 > 0 || need_number?(test2)
+      end
+    else
+      false
+    end
   end
   def row_blocks
     # All cells in an Excel document are divided into blocks of 32 consecutive

test/excel/writer/worksheet.rb

@@ -15,6 +15,7 @@ def test_need_number
     assert_equal false, sheet.need_number?(0.1)
     assert_equal false, sheet.need_number?(0.01)
     assert_equal true, sheet.need_number?(0.001)
+    assert_equal true, sheet.need_number?(10000000.0)
   end
 end
     end

test/integration.rb

@@ -1185,5 +1185,29 @@ def test_bignum
       assert_equal smallnum - 0.1, book.worksheet(0)[0,3]
       assert_equal(-smallnum - 0.1, book.worksheet(0)[1,3])
     end
+    def test_bigfloat
+      # reported in http://rubyforge.org/tracker/index.php?func=detail&aid=24119&group_id=678&atid=2677
+      bigfloat = 10000000.0
+      book = Spreadsheet::Workbook.new
+      sheet = book.create_worksheet
+      sheet[0,0] = bigfloat
+      sheet[0,1] = bigfloat + 0.1
+      sheet[0,2] = bigfloat - 0.1
+      sheet[1,0] = -bigfloat
+      sheet[1,1] = -bigfloat + 0.1
+      sheet[1,2] = -bigfloat - 0.1
+      path = File.join @var, 'test_big-float.xls'
+      book.write path
+      assert_nothing_raised do
+        book = Spreadsheet.open path
+      end
+      sheet = book.worksheet(0)
+      assert_equal bigfloat, sheet[0,0]
+      assert_equal bigfloat + 0.1, sheet[0,1]
+      assert_equal bigfloat - 0.1, sheet[0,2]
+      assert_equal -bigfloat, sheet[1,0]
+      assert_equal -bigfloat + 0.1, sheet[1,1]
+      assert_equal -bigfloat - 0.1, sheet[1,2]
+    end
   end
 end