Fix incorrect class type for widgets.

src/View/Widget/WidgetRegistry.php

@@ -177,7 +177,7 @@ class WidgetRegistry {
 		}
 
 		$class = array_shift($widget);
-		$className = App::className($class, 'View/Input');
+		$className = App::className($class, 'View/Widget');
 		if ($className === false || !class_exists($className)) {
 			throw new \RuntimeException(sprintf('Unable to locate widget class "%s"', $class));
 		}

tests/TestCase/View/Widget/WidgetRegistryTest.php

@@ -44,10 +44,14 @@ class WidgetRegistryTestCase extends TestCase {
 	public function testAddInConstructor() {
 		$widgets = [
 			'text' => ['Cake\View\Widget\Basic'],
+			'label' => ['Label'],
 		];
 		$inputs = new WidgetRegistry($this->templates, $this->view, $widgets);
 		$result = $inputs->get('text');
 		$this->assertInstanceOf('Cake\View\Widget\Basic', $result);
+
+		$result = $inputs->get('label');
+		$this->assertInstanceOf('Cake\View\Widget\Label', $result);
 	}
 
 /**