diff --git a/src/Symfony/Bridge/Doctrine/Form/ChoiceList/ORMQueryBuilderLoader.php b/src/Symfony/Bridge/Doctrine/Form/ChoiceList/ORMQueryBuilderLoader.php
index fe0ad19367..c887ae6b38 100644
--- a/src/Symfony/Bridge/Doctrine/Form/ChoiceList/ORMQueryBuilderLoader.php
+++ b/src/Symfony/Bridge/Doctrine/Form/ChoiceList/ORMQueryBuilderLoader.php
@@ -89,7 +89,7 @@ class ORMQueryBuilderLoader implements EntityLoaderInterface
      */
     public function getEntitiesByIds($identifier, array $values)
     {
-        $qb = clone ($this->queryBuilder);
+        $qb = clone $this->queryBuilder;
         $alias = current($qb->getRootAliases());
         $parameter = 'ORMQueryBuilderLoader_getEntitiesByIds_'.$identifier;
         $where = $qb->expr()->in($alias.'.'.$identifier, ':'.$parameter);
diff --git a/src/Symfony/Component/DependencyInjection/Compiler/ReplaceAliasByActualDefinitionPass.php b/src/Symfony/Component/DependencyInjection/Compiler/ReplaceAliasByActualDefinitionPass.php
index 972d708c59..8308937d4a 100644
--- a/src/Symfony/Component/DependencyInjection/Compiler/ReplaceAliasByActualDefinitionPass.php
+++ b/src/Symfony/Component/DependencyInjection/Compiler/ReplaceAliasByActualDefinitionPass.php
@@ -45,7 +45,7 @@ class ReplaceAliasByActualDefinitionPass implements CompilerPassInterface
             try {
                 $definition = $container->getDefinition($aliasId);
             } catch (InvalidArgumentException $e) {
-                throw new InvalidArgumentException(sprintf('Unable to replace alias "%s" with "%s".', $alias, $id), null, $e);
+                throw new InvalidArgumentException(sprintf('Unable to replace alias "%s" with actual definition "%s".', $id, $alias), null, $e);
             }
 
             if ($definition->isPublic()) {
diff --git a/src/Symfony/Component/Filesystem/Filesystem.php b/src/Symfony/Component/Filesystem/Filesystem.php
index 93a1f0de4c..864a46d9cb 100644
--- a/src/Symfony/Component/Filesystem/Filesystem.php
+++ b/src/Symfony/Component/Filesystem/Filesystem.php
@@ -443,13 +443,13 @@ class Filesystem
      */
     public function isAbsolutePath($file)
     {
-        return (strspn($file, '/\\', 0, 1)
+        return strspn($file, '/\\', 0, 1)
             || (strlen($file) > 3 && ctype_alpha($file[0])
                 && substr($file, 1, 1) === ':'
                 && (strspn($file, '/\\', 2, 1))
             )
             || null !== parse_url($file, PHP_URL_SCHEME)
-        );
+        ;
     }
 
     /**
diff --git a/src/Symfony/Component/Finder/Iterator/SortableIterator.php b/src/Symfony/Component/Finder/Iterator/SortableIterator.php
index b32ac8d6df..fa3458077a 100644
--- a/src/Symfony/Component/Finder/Iterator/SortableIterator.php
+++ b/src/Symfony/Component/Finder/Iterator/SortableIterator.php
@@ -55,15 +55,15 @@ class SortableIterator implements \IteratorAggregate
             };
         } elseif (self::SORT_BY_ACCESSED_TIME === $sort) {
             $this->sort = function ($a, $b) {
-                return ($a->getATime() - $b->getATime());
+                return $a->getATime() - $b->getATime();
             };
         } elseif (self::SORT_BY_CHANGED_TIME === $sort) {
             $this->sort = function ($a, $b) {
-                return ($a->getCTime() - $b->getCTime());
+                return $a->getCTime() - $b->getCTime();
             };
         } elseif (self::SORT_BY_MODIFIED_TIME === $sort) {
             $this->sort = function ($a, $b) {
-                return ($a->getMTime() - $b->getMTime());
+                return $a->getMTime() - $b->getMTime();
             };
         } elseif (is_callable($sort)) {
             $this->sort = $sort;
diff --git a/src/Symfony/Component/HttpFoundation/Response.php b/src/Symfony/Component/HttpFoundation/Response.php
index e28ac46e04..97e11516d9 100644
--- a/src/Symfony/Component/HttpFoundation/Response.php
+++ b/src/Symfony/Component/HttpFoundation/Response.php
@@ -972,7 +972,7 @@ class Response
      * Sets the Vary header.
      *
      * @param string|array $headers
-     * @param bool         $replace Whether to replace the actual value of not (true by default)
+     * @param bool         $replace Whether to replace the actual value or not (true by default)
      *
      * @return Response
      */
diff --git a/src/Symfony/Component/HttpFoundation/Session/Storage/Proxy/AbstractProxy.php b/src/Symfony/Component/HttpFoundation/Session/Storage/Proxy/AbstractProxy.php
index 1036818277..463677b55a 100644
--- a/src/Symfony/Component/HttpFoundation/Session/Storage/Proxy/AbstractProxy.php
+++ b/src/Symfony/Component/HttpFoundation/Session/Storage/Proxy/AbstractProxy.php
@@ -52,7 +52,7 @@ abstract class AbstractProxy
      */
     public function isSessionHandlerInterface()
     {
-        return ($this instanceof \SessionHandlerInterface);
+        return $this instanceof \SessionHandlerInterface;
     }
 
     /**
diff --git a/src/Symfony/Component/Intl/DateFormatter/DateFormat/FullTransformer.php b/src/Symfony/Component/Intl/DateFormatter/DateFormat/FullTransformer.php
index 3c3410e879..84d5179e57 100644
--- a/src/Symfony/Component/Intl/DateFormatter/DateFormat/FullTransformer.php
+++ b/src/Symfony/Component/Intl/DateFormatter/DateFormat/FullTransformer.php
@@ -214,7 +214,7 @@ class FullTransformer
      */
     public function isQuoteMatch($quoteMatch)
     {
-        return ("'" === $quoteMatch[0]);
+        return "'" === $quoteMatch[0];
     }
 
     /**
diff --git a/src/Symfony/Component/Process/Process.php b/src/Symfony/Component/Process/Process.php
index c1e732170f..ed4255f077 100644
--- a/src/Symfony/Component/Process/Process.php
+++ b/src/Symfony/Component/Process/Process.php
@@ -1409,6 +1409,11 @@ class Process
             $this->exitcode = 128 + $this->processInformation['termsig'];
         }
 
+        // Free memory from self-reference callback created by buildCallback
+        // Doing so in other contexts like __destruct or by garbage collector is ineffective
+        // Now pipes are closed, so the callback is no longer necessary
+        $this->callback = null;
+
         return $this->exitcode;
     }
 
diff --git a/src/Symfony/Component/Yaml/Parser.php b/src/Symfony/Component/Yaml/Parser.php
index cdc6caac93..2d3413e1de 100644
--- a/src/Symfony/Component/Yaml/Parser.php
+++ b/src/Symfony/Component/Yaml/Parser.php
@@ -707,6 +707,6 @@ class Parser
      */
     private function isStringUnIndentedCollectionItem()
     {
-        return (0 === strpos($this->currentLine, '- '));
+        return 0 === strpos($this->currentLine, '- ');
     }
 }