Merge branch '3.4'

* 3.4:
  include file and line number in deprecation
  parse merge keys with PARSE_OBJECT_FOR_MAP flag

Author: xabbuh

Loader/YamlFileLoader.php

@@ -57,10 +57,18 @@ public function load($file, $type = null)
             $this->yamlParser = new YamlParser();
         }
 
+        $prevErrorHandler = set_error_handler(function ($level, $message, $script, $line) use ($file, &$prevErrorHandler) {
+            $message = E_USER_DEPRECATED === $level ? preg_replace('/ on line \d+/', ' in "'.$file.'"$0', $message) : $message;
+
+            return $prevErrorHandler ? $prevErrorHandler($level, $message, $script, $line) : false;
+        });
+
         try {
             $parsedConfig = $this->yamlParser->parseFile($path);
         } catch (ParseException $e) {
             throw new \InvalidArgumentException(sprintf('The file "%s" does not contain valid YAML.', $path), 0, $e);
+        } finally {
+            restore_error_handler();
         }
 
         $collection = new RouteCollection();