Merge branch '2.8' into 3.2

* 2.8:
  [2.8] Prevent double registrations related to tag priorities
  Prevent double registrations related to tag priorities

Author: fabpot

src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/Compiler/PropertyInfoPassTest.php

@@ -20,9 +20,9 @@ class PropertyInfoPassTest extends TestCase
     public function testServicesAreOrderedAccordingToPriority()
     {
         $services = array(
-            'n3' => array('tag' => array()),
-            'n1' => array('tag' => array('priority' => 200)),
-            'n2' => array('tag' => array('priority' => 100)),
+            'n3' => array(array()),
+            'n1' => array(array('priority' => 200)),
+            'n2' => array(array('priority' => 100)),
         );
 
         $expected = array(

src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/Compiler/SerializerPassTest.php

@@ -72,9 +72,9 @@ public function testThrowExceptionWhenNoEncoders()
     public function testServicesAreOrderedAccordingToPriority()
     {
         $services = array(
-            'n3' => array('tag' => array()),
-            'n1' => array('tag' => array('priority' => 200)),
-            'n2' => array('tag' => array('priority' => 100)),
+            'n3' => array(array()),
+            'n1' => array(array('priority' => 200)),
+            'n2' => array(array('priority' => 100)),
         );
 
         $expected = array(

src/Symfony/Bundle/TwigBundle/DependencyInjection/Compiler/TwigLoaderPass.php

@@ -29,27 +29,23 @@ public function process(ContainerBuilder $container)
             return;
         }
 
-        // register additional template loaders
-        $loaderIds = $container->findTaggedServiceIds('twig.loader');
+        $prioritizedLoaders = array();
+        $found = 0;
 
-        if (count($loaderIds) === 0) {
+        foreach ($container->findTaggedServiceIds('twig.loader') as $id => $attributes) {
+            $priority = isset($attributes[0]['priority']) ? $attributes[0]['priority'] : 0;
+            $prioritizedLoaders[$priority][] = $id;
+            ++$found;
+        }
+
+        if (!$found) {
             throw new LogicException('No twig loaders found. You need to tag at least one loader with "twig.loader"');
         }
 
-        if (count($loaderIds) === 1) {
-            $container->setAlias('twig.loader', key($loaderIds));
+        if (1 === $found) {
+            $container->setAlias('twig.loader', $id);
         } else {
             $chainLoader = $container->getDefinition('twig.loader.chain');
-
-            $prioritizedLoaders = array();
-
-            foreach ($loaderIds as $id => $tags) {
-                foreach ($tags as $tag) {
-                    $priority = isset($tag['priority']) ? $tag['priority'] : 0;
-                    $prioritizedLoaders[$priority][] = $id;
-                }
-            }
-
             krsort($prioritizedLoaders);
 
             foreach ($prioritizedLoaders as $loaders) {