P5-2895 - Fix and sanitize cropping numbers

src/Viewport.js

@@ -75,8 +75,8 @@ function Viewport(canvas) {
             fill: 'transparent',
             width: _data.width,
             height: _data.height,
-            stroke: '#fff',
-            strokeWidth: canvas.__type === 'canvas' ? 0 : _borderWidth
+            stroke: canvas.__type === 'canvas' ? 'transparent' : '#fff',
+            strokeWidth: _borderWidth,
         });
 
         _rect.width += _borderWidth;