fixed negative width/height corner radius

src/Util.ts

@@ -995,6 +995,11 @@ export const Util = {
     height: number,
     cornerRadius: number | number[]
   ) {
+    // if negative dimensions, abs width/height and move rectangle
+    let xOrigin = width < 0 ? width : 0;
+    let yOrigin = height < 0 ? height : 0;
+    width = Math.abs(width);
+    height = Math.abs(height);
     let topLeft = 0;
     let topRight = 0;
     let bottomLeft = 0;
@@ -1011,35 +1016,42 @@ export const Util = {
       bottomRight = Math.min(cornerRadius[2] || 0, width / 2, height / 2);
       bottomLeft = Math.min(cornerRadius[3] || 0, width / 2, height / 2);
     }
-    context.moveTo(topLeft, 0);
+    context.moveTo(xOrigin + topLeft, yOrigin);
-    context.lineTo(width - topRight, 0);
+    context.lineTo(xOrigin + width - topRight, yOrigin);
     context.arc(
-      width - topRight,
+      xOrigin + width - topRight,
-      topRight,
+      yOrigin + topRight,
       topRight,
       (Math.PI * 3) / 2,
       0,
       false
     );
-    context.lineTo(width, height - bottomRight);
+    context.lineTo(xOrigin + width, yOrigin + height - bottomRight);
     context.arc(
-      width - bottomRight,
+      xOrigin + width - bottomRight,
-      height - bottomRight,
+      yOrigin + height - bottomRight,
       bottomRight,
       0,
       Math.PI / 2,
       false
     );
-    context.lineTo(bottomLeft, height);
+    context.lineTo(xOrigin + bottomLeft, yOrigin + height);
     context.arc(
-      bottomLeft,
+      xOrigin + bottomLeft,
-      height - bottomLeft,
+      yOrigin + height - bottomLeft,
       bottomLeft,
       Math.PI / 2,
       Math.PI,
       false
     );
-    context.lineTo(0, topLeft);
+    context.lineTo(xOrigin, yOrigin + topLeft);
-    context.arc(topLeft, topLeft, topLeft, Math.PI, (Math.PI * 3) / 2, false);
+    context.arc(
+        xOrigin + topLeft, 
+        yOrigin + topLeft, 
+        topLeft, 
+        Math.PI, 
+        (Math.PI * 3) / 2, 
+        false
+    );
   },
 };

test/unit/Rect-test.ts

@@ -234,4 +234,28 @@ describe('Rect', function () {
       'clearRect(0,0,578,200);save();transform(1,0,0,1,50,50);beginPath();moveTo(0,0);lineTo(90,0);arc(90,10,10,4.712,0,false);lineTo(100,80);arc(80,80,20,0,1.571,false);lineTo(30,100);arc(30,70,30,1.571,3.142,false);lineTo(0,0);arc(0,0,0,3.142,4.712,false);closePath();fillStyle=black;fill();restore();clearRect(0,0,578,200);save();transform(1,0,0,1,50,50);beginPath();moveTo(0,0);lineTo(90,0);arc(90,10,10,4.712,0,false);lineTo(100,80);arc(80,80,20,0,1.571,false);lineTo(30,100);arc(30,70,30,1.571,3.142,false);lineTo(0,0);arc(0,0,0,3.142,4.712,false);closePath();fillStyle=black;fill();restore();'
     );
   });
+
+  // ======================================================
+  it('corner radius with negative width and height', function () {
+    var stage = addStage();
+    var layer = new Konva.Layer();
+    var rect = new Konva.Rect({
+      x: 100,
+      y: 100,
+      width: -100,
+      height: -100,
+      fill: 'black',
+      cornerRadius: [0, 10, 20, 30],
+    });
+
+    layer.add(rect);
+    stage.add(layer);
+    layer.draw();
+
+    var trace = layer.getContext().getTrace();
+    assert.equal(
+      trace,
+      'clearRect(0,0,578,200);save();transform(1,0,0,1,100,100);beginPath();moveTo(-100,-100);lineTo(-10,-100);arc(-10,-90,10,4.712,0,false);lineTo(0,-20);arc(-20,-20,20,0,1.571,false);lineTo(-70,0);arc(-70,-30,30,1.571,3.142,false);lineTo(-100,-100);arc(-100,-100,0,3.142,4.712,false);closePath();fillStyle=black;fill();restore();clearRect(0,0,578,200);save();transform(1,0,0,1,100,100);beginPath();moveTo(-100,-100);lineTo(-10,-100);arc(-10,-90,10,4.712,0,false);lineTo(0,-20);arc(-20,-20,20,0,1.571,false);lineTo(-70,0);arc(-70,-30,30,1.571,3.142,false);lineTo(-100,-100);arc(-100,-100,0,3.142,4.712,false);closePath();fillStyle=black;fill();restore();'
+    );
+    });
 });