Add regression test for event target on Control

* Check possible name collision of target element with EventTarget

test/spec/ol/control/control.test.js

@@ -54,3 +54,25 @@ describe('ol.control.Control\'s target', function() {
     });
   });
 });
+
+describe('ol.control.Control\'s event target', function() {
+  it('is the Control when the Control uses the default target', function() {
+    const ctrl = new Control({element: document.createElement('div')});
+    ctrl.on('test-event', function(e) {
+      expect(e.target).to.be(ctrl);
+    });
+    ctrl.dispatchEvent('test-event');
+    ctrl.dispose();
+  });
+  it('is the Control when the Control has a custom target', function() {
+    const ctrl = new Control({
+      element: document.createElement('div'),
+      target: document.createElement('div')
+    });
+    ctrl.on('test-event', function(e) {
+      expect(e.target).to.be(ctrl);
+    });
+    ctrl.dispatchEvent('test-event');
+    ctrl.dispose();
+  });
+});