910126 - another unexpected result from Graphics.DrawImage

Hi,
In the following code:

void f10(Graphics g)
{
	var img = new Bitmap(1, 1);
	img.SetPixel(0, 0, Color.Black);
	var destRect = pictureBox1.ClientRectangle;
	destRect.Inflate(-5, -5);
	g.DrawRectangle(new Pen(Color.Blue), destRect);
	var srcRect = new RectangleF(-.5f, -.5f, img.Width, img.Height);
	g.InterpolationMode = InterpolationMode.NearestNeighbor;
	g.DrawImage(img, destRect, srcRect, GraphicsUnit.Pixel);
}

private void pictureBox1_Paint(object sender, PaintEventArgs e)
{
	f10(e.Graphics);
}

private void pictureBox1_Resize(object sender, EventArgs e)
{
	textBox1.Text = pictureBox1.ClientSize.Width + "x" + pictureBox1.ClientSize.Height;
	pictureBox1.Invalidate();
}

I get the following result:

Result

The form contains a picture box that fits the whole inside content of the form and a text box that shows the dimensions of the picture box. I expect the right side of the black box to fit the whole inside of the blue rectangle. Why it doesn't?!

Unexpected gap

By changing the values of dimensions (resizing the picture box) the gap changes.

Tags: C#, GDI+