MAGETWO-43691: Custom admin path does not work correctly

 - initial implementation

Author: monkeysee

app/code/Magento/Backend/App/Area/FrontNameResolver.php

@@ -41,20 +41,33 @@ class FrontNameResolver implements \Magento\Framework\App\Area\FrontNameResolver
     /**
      * @param \Magento\Backend\App\Config $config
      * @param DeploymentConfig $deploymentConfig
+     * @param \Magento\Backend\Model\UrlInterface $backendUrl
      */
-    public function __construct(\Magento\Backend\App\Config $config, DeploymentConfig $deploymentConfig)
+    public function __construct(
+        \Magento\Backend\App\Config $config,
+        DeploymentConfig $deploymentConfig,
+        \Magento\Backend\Model\UrlInterface $backendUrl
+    )
     {
         $this->config = $config;
         $this->defaultFrontName = $deploymentConfig->get(ConfigOptionsList::CONFIG_PATH_BACKEND_FRONTNAME);
+        $this->backendUrl = $backendUrl;
     }
 
     /**
      * Retrieve area front name
      *
+     * @param string $host If set, verify front name is valid for this url (hostname is correct)
      * @return string
      */
-    public function getFrontName()
+    public function getFrontName($host = null)
     {
+        if ($host) {
+            $bu = $this->backendUrl->getBaseUrl();
+            if (stripos($bu, $host) === false) {
+                return false;
+            }
+        }
         $isCustomPathUsed = (bool)(string)$this->config->getValue(self::XML_PATH_USE_CUSTOM_ADMIN_PATH);
         if ($isCustomPathUsed) {
             return (string)$this->config->getValue(self::XML_PATH_CUSTOM_ADMIN_PATH);

app/code/Magento/Backend/App/Router/NoRouteHandler.php

@@ -19,16 +19,24 @@ class NoRouteHandler implements \Magento\Framework\App\Router\NoRouteHandlerInte
      */
     protected $routeConfig;
 
+    /**
+     * @var \Magento\Backend\Model\UrlInterface
+     */
+    protected $backendUrl;
+
     /**
      * @param \Magento\Backend\Helper\Data $helper
      * @param \Magento\Framework\App\Route\ConfigInterface $routeConfig
+     * @param \Magento\Backend\Model\UrlInterface $backendUrl
      */
     public function __construct(
         \Magento\Backend\Helper\Data $helper,
-        \Magento\Framework\App\Route\ConfigInterface $routeConfig
+        \Magento\Framework\App\Route\ConfigInterface $routeConfig,
+        \Magento\Backend\Model\UrlInterface $backendUrl
     ) {
         $this->helper = $helper;
         $this->routeConfig = $routeConfig;
+        $this->backendUrl = $backendUrl;
     }
 
     /**
@@ -43,11 +51,15 @@ public function process(\Magento\Framework\App\RequestInterface $request)
         $areaFrontName = array_shift($requestPathParams);
 
         if ($areaFrontName == $this->helper->getAreaFrontName()) {
-            $moduleName = $this->routeConfig->getRouteFrontName('adminhtml');
-            $actionNamespace = 'noroute';
-            $actionName = 'index';
-            $request->setModuleName($moduleName)->setControllerName($actionNamespace)->setActionName($actionName);
-            return true;
+            $baseUrl = $this->backendUrl->getBaseUrl();
+            if (!stripos($baseUrl, $_SERVER['HTTP_HOST']) === false)
+            {
+                $moduleName = $this->routeConfig->getRouteFrontName('adminhtml');
+                $actionNamespace = 'noroute';
+                $actionName = 'index';
+                $request->setModuleName($moduleName)->setControllerName($actionNamespace)->setActionName($actionName);
+                return true;
+            }
         }
         return false;
     }

lib/internal/Magento/Framework/App/Area/FrontNameResolverInterface.php

@@ -16,7 +16,8 @@ interface FrontNameResolverInterface
     /**
      * Retrieve front name
      *
-     * @return string
+     * @param null|string $host If set, only return frontname if it is valid for the host
+     * @return null|string
      */
-    public function getFrontName();
+    public function getFrontName($host = null);
 }

lib/internal/Magento/Framework/App/AreaList.php

@@ -69,9 +69,8 @@ public function getCodeByFrontName($frontName)
     {
         foreach ($this->_areas as $areaCode => &$areaInfo) {
             if (!isset($areaInfo['frontName']) && isset($areaInfo['frontNameResolver'])) {
-                $areaInfo['frontName'] = $this->_resolverFactory->create(
-                    $areaInfo['frontNameResolver']
-                )->getFrontName();
+                $resolver = $this->_resolverFactory->create($areaInfo['frontNameResolver']);
+                $areaInfo['frontName'] = $resolver->getFrontName($_SERVER['HTTP_HOST']);
             }
             if ($areaInfo['frontName'] == $frontName) {
                 return $areaCode;