Calculation failure in date cell

[masashi68]

Please fix calculation.

The following calculation fails
=IF(A1 = "","A","B")
A1 <- Date cell

I propose the following corrections.

in ClosedXml.Excel.CalcEngine.Expression

	public static implicit operator DateTime(Expression x)
	{
		// evaluate
		var v = x.Evaluate();

		// handle dates
		if (v is DateTime)
		{
			return (DateTime)v;
		}

		// handle doubles
		if (v is double || v is int)
		{
			return DateTime.FromOADate((double)x);
		}

		// !!!!!NEW CODE !!!!!
		if (v is string || (string)v == "")
		{
			return DateTime.MinValue;
		}
		// !!!!!NEW CODE !!!!!

		 // handle everything else
		  CultureInfo _ci = Thread.CurrentThread.CurrentCulture;
		  return (DateTime)Convert.ChangeType(v, typeof(DateTime), _ci);
	}

Thanks!

[masashi68]

ClosedXmlTest.zip

[igitur]

Thanks, but your changes break a lot of other tests. I will look into a different solution to the problem.

[masashi68]

Thanks!
I am looking forward to installing from nget.