Merge branch '3.4'

* 3.4:
  Added a note about cache:clear and cache:pool:clear
  Improved the first example of the Guard authenticator
  Deprecated the web_profiler.position option

Author: xabbuh

components/cache/cache_pools.rst

@@ -130,11 +130,16 @@ when all items are successfully deleted)::
     .. code-block:: terminal
 
         $ php bin/console cache:pool:clear <cache-pool-name>
-        
+
         # clears the "cache.app" pool
         $ php bin/console cache:pool:clear cache.app
 
         # clears the "cache.validation" and "cache.app" pool
         $ php bin/console cache:pool:clear cache.validation cache.app
 
+    .. versionadded:: 3.4
+        Starting from Symfony 3.4, the ``cache:clear`` command no longer clears
+        the cache pools, so you must use the ``cache:pool:clear`` command to
+        delete them.
+
 .. _`Doctrine Cache`: https://github.com/doctrine/cache

security/guard_authentication.rst

@@ -173,23 +173,17 @@ This requires you to implement several methods::
          */
         public function supports(Request $request)
         {
-            return true;
+            return $request->headers->has('X-AUTH-TOKEN')
         }
 
         /**
          * Called on every request. Return whatever credentials you want to
-         * be passed to getUser().
+         * be passed to getUser() as $credentials.
          */
         public function getCredentials(Request $request)
         {
-            if (!$token = $request->headers->get('X-AUTH-TOKEN')) {
-                // No token?
-                $token = null;
-            }
-
-            // What you return here will be passed to getUser() as $credentials
             return array(
-                'token' => $token,
+                'token' => $request->headers->get('X-AUTH-TOKEN'),
             );
         }