Toplevel.EnsureVisibleBounds throws an exception if border is null.

[BDisp]

This unit test proves that:

public void EnsureVisibleBounds_With_Border_Null_Not_Throws ()
{
	var top = new Toplevel ();
	Application.Begin (top);

	var exception = Record.Exception (() => ((FakeDriver)Application.Driver).SetBufferSize (0, 10));
	Assert.Null (exception);

	exception = Record.Exception (() => ((FakeDriver)Application.Driver).SetBufferSize (10, 0));
	Assert.Null (exception);
}

Here a print screen of the error if the console height is resized to zero: