Ensure navigation plugin manager initializer works properly

- Adds a test to ensure that the parent container is injected into
  navigation helpers by the initializer created in the navigation
  PluginManager constructor, and fixes the code to work correctly.

Author: weierophinney

src/Helper/Navigation/PluginManager.php

@@ -65,11 +65,31 @@ class PluginManager extends HelperPluginManager
      */
     public function __construct($configOrContainerInstance = null, array $v3config = [])
     {
-        $this->initializers[] = function ($container, $instance) {
+        $this->initializers[] = function ($first, $second) {
+            // v2 vs v3 argument order
+            if ($first instanceof ContainerInterface) {
+                // v3
+                $container = $first;
+                $instance = $second;
+            } else {
+                // v2
+                $container = $second;
+                $instance = $first;
+            }
+
             if (! $instance instanceof AbstractHelper) {
                 return;
             }
 
+            // This initializer was written with v2 functionality in mind; as such,
+            // we need to test and see if we're called in a v2 context, and, if so,
+            // set the service locator to the parent locator.
+            //
+            // Under v3, the parent locator is what is passed to the method already.
+            if (method_exists($container, 'getServiceLocator') && $container->getServiceLocator()) {
+                $container = $container->getServiceLocator();
+            }
+
             $instance->setServiceLocator($container);
         };
 

test/Helper/Navigation/PluginManagerCompatibilityTest.php

@@ -14,6 +14,7 @@
 use Zend\ServiceManager\Test\CommonPluginManagerTrait;
 use Zend\View\Exception\InvalidHelperException;
 use Zend\View\Helper\Navigation\AbstractHelper;
+use Zend\View\Helper\Navigation\Breadcrumbs;
 use Zend\View\Helper\Navigation\PluginManager;
 
 /**
@@ -65,4 +66,26 @@ public function testConstructorAllowsConfigInstanceAsFirstArgumentUnderV2()
         $helpers = new PluginManager(new Config([]));
         $this->assertInstanceOf(PluginManager::class, $helpers);
     }
+
+    public function testInjectsParentContainerIntoHelpersUnderV2()
+    {
+        $helpers = $this->getPluginManager();
+        if (method_exists($helpers, 'configure')) {
+            $this->markTestSkipped('This test is specific to v2 functionality');
+        }
+
+        $config = new Config([
+            'navigation' => [
+                'default' => [],
+            ],
+        ]);
+
+        $services = new ServiceManager();
+        $config->configureServiceManager($services);
+        $helpers = new PluginManager($services);
+
+        $helper = $helpers->get('breadcrumbs');
+        $this->assertInstanceOf(Breadcrumbs::class, $helper);
+        $this->assertSame($services, $helper->getServiceLocator());
+    }
 }