Merge branch '2.7' into 2.8

* 2.7:
  [Validator] added magic method __isset()  to File Constraint class
  [DI] Fix possible incorrect php-code when dumped strings contains newlines
  [Translation] minor: remove unused variable in test
  never match invalid IP addresses

Author: nicolas-grekas

Dumper/PhpDumper.php

@@ -1587,6 +1587,13 @@ private function export($value)
             return $dirname;
         }
 
+        if (is_string($value) && false !== strpos($value, "\n")) {
+            $cleanParts = explode("\n", $value);
+            $cleanParts = array_map(function ($part) { return var_export($part, true); }, $cleanParts);
+
+            return implode('."\n".', $cleanParts);
+        }
+
         return var_export($value, true);
     }
 }

Tests/Dumper/PhpDumperTest.php

@@ -55,6 +55,7 @@ public function testDumpOptimizationString()
             'optimize concatenation with empty string' => 'string1%empty_value%string2',
             'optimize concatenation from the start' => '%empty_value%start',
             'optimize concatenation at the end' => 'end%empty_value%',
+            'new line' => "string with \nnew line",
         ));
 
         $container = new ContainerBuilder();

Tests/Fixtures/php/services10.php

@@ -56,7 +56,7 @@ public function isFrozen()
      */
     protected function getTestService()
     {
-        return $this->services['test'] = new \stdClass(array('only dot' => '.', 'concatenation as value' => '.\'\'.', 'concatenation from the start value' => '\'\'.', '.' => 'dot as a key', '.\'\'.' => 'concatenation as a key', '\'\'.' => 'concatenation from the start key', 'optimize concatenation' => 'string1-string2', 'optimize concatenation with empty string' => 'string1string2', 'optimize concatenation from the start' => 'start', 'optimize concatenation at the end' => 'end'));
+        return $this->services['test'] = new \stdClass(array('only dot' => '.', 'concatenation as value' => '.\'\'.', 'concatenation from the start value' => '\'\'.', '.' => 'dot as a key', '.\'\'.' => 'concatenation as a key', '\'\'.' => 'concatenation from the start key', 'optimize concatenation' => 'string1-string2', 'optimize concatenation with empty string' => 'string1string2', 'optimize concatenation from the start' => 'start', 'optimize concatenation at the end' => 'end', 'new line' => 'string with '."\n".'new line'));
     }
 
     /**