image class will not make invalid render calls if its size is 0 causing divide by zero and passing .NaN to drawing context.

src/Avalonia.Controls/Image.cs

@@ -69,10 +69,11 @@ namespace Avalonia.Controls
         {
             var source = Source;
 
-            if (source != null)
+            if (source != null && Bounds.Size != Size.Empty)
             {
                 Rect viewPort = new Rect(Bounds.Size);
                 Size sourceSize = source.Size;
+
                 Vector scale = Stretch.CalculateScaling(Bounds.Size, sourceSize, StretchDirection);
                 Size scaledSize = sourceSize * scale;
                 Rect destRect = viewPort