Remove hoveredTarget reference if object is removed (#3657)

* Remove hoveredTarget reference if object is removed
* Update canvas.js tests
* remove trailing spaces

src/canvas.class.js

@@ -1380,6 +1380,9 @@
         this.fire('selection:cleared', { target: obj });
         obj.fire('deselected');
       }
+      if (this._hoveredTarget === obj) {
+        this._hoveredTarget = null;
+      }
       this.callSuper('_onObjectRemoved', obj);
     },
 

test/unit/canvas.js

@@ -256,6 +256,14 @@
     equal(canvas.isEmpty(), true, 'canvas should be empty');
   });
 
+  test('remove actual hovered target', function() {
+    var rect1 = makeRect();
+    canvas.add(rect1);
+    canvas._hoveredTarget = rect1;
+    canvas.remove(rect1);
+    equal(canvas._hoveredTarget, null, 'reference to hovered target should be removed');
+  });
+
   test('before:selection:cleared', function() {
     var isFired = false;
     canvas.on('before:selection:cleared', function() { isFired = true; });