Merge branch '2.8' into 3.0

* 2.8:
  [CS] Respect PSR2 4.2
  [Form] fix `empty_data` option in expanded `ChoiceType`
  [Console] removed unneeded private methods
  [Security] [Guard] Improve comment with working example
  sync min email validator version
  [TwigBridge] Fix inconsistency in LintCommand help
  explicitly forbid e-mail validator 2.0 or higher
  Fixed SymfonyQuestionHelper multi-choice with defaults
  [DoctrineBridge] Don't use object IDs in DoctrineChoiceLoader when passing a value closure
  Differentiate between the first time a progress bar is displayed and subsequent times
  finished previous commit
  No more exception for malformed input name
  fix post_max_size_message translation
  [Process] Fix pipes cleaning on Windows
  Avoid phpunit 5.4 warnings on getMock
  [Form] Add exception to FormRenderer about non-unique block names
  [Form] Consider a violation even if the form is not submitted

Author: fabpot

Form/ChoiceList/DoctrineChoiceLoader.php

@@ -110,9 +110,10 @@ public function loadValuesForChoices(array $choices, $value = null)
 
         // Optimize performance for single-field identifiers. We already
         // know that the IDs are used as values
+        $optimize = null === $value || is_array($value) && $value[0] === $this->idReader;
 
         // Attention: This optimization does not check choices for existence
-        if (!$this->choiceList && $this->idReader->isSingleId()) {
+        if ($optimize && !$this->choiceList && $this->idReader->isSingleId()) {
             $values = array();
 
             // Maintain order and indices of the given objects