Splitting of shared formulas fails

[sonix1977nl]

If you have a shared formula in a column and you try to update a range where the end row is larger than that of the shared formula, you get an address out of range exception that is caused by ExcelRangeBase.SplitFormula.

This problem can be simply replayed with the following code:

var package = new ExcelPackage();
var sheet = package.Workbook.Worksheets.Add("Test");
sheet.Cells["A2:A4"].Formula = "NOW()";
// The line below will cause an exception.
sheet.Cells["A2:A5"].Value = null;