MAGETWO-51929: [Github] [Deferred for 2.1 GA] Web Setup Wizard does not work when Magento is installed in pub #4159

- Updates based on review comments
- Moved MenuBuilder plugin to adminhtml/di.xml
- Updated DocRootLocator logic to look for "/pub" at the end of the base path

Author: ark99

app/code/Magento/Backend/etc/adminhtml/di.xml

@@ -138,4 +138,7 @@
             <argument name="isIncludesAvailable" xsi:type="boolean">false</argument>
         </arguments>
     </type>
+    <type name="Magento\Backend\Model\Menu\Builder">
+        <plugin name="SetupMenuBuilder" type="Magento\Backend\Model\Setup\MenuBuilder" />
+    </type>
 </config>

app/code/Magento/Backend/etc/di.xml

@@ -214,7 +214,4 @@
             </argument>
         </arguments>
     </type>
-    <type name="Magento\Backend\Model\Menu\Builder">
-        <plugin name="SetupMenuBuilder" type="Magento\Backend\Model\Setup\MenuBuilder" />
-    </type>
 </config>

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

@@ -43,6 +43,6 @@ public function isPub()
     {
         $rootBasePath = $this->request->getServer('DOCUMENT_ROOT');
         $readDirectory = $this->readFactory->create(DirectoryList::ROOT);
-        return strpos($rootBasePath, 'pub') && !$readDirectory->isExist($rootBasePath . 'setup');
+        return (substr($rootBasePath, -strlen('/pub')) === '/pub') && !$readDirectory->isExist($rootBasePath . 'setup');
     }
 }