Merge branch '2.8' into 3.0

* 2.8:
  fixed CS
  [DomCrawler] Dont use LIBXML_PARSEHUGE by default
  [Filesystem] Reduce complexity of ->remove()
  added tests for non-trusted proxies
  add 'guid' to list of exception to filter out
  Ensure backend slashes for symlinks on Windows systems
  [Filesystem] Try to delete broken symlinks
  fixed tests
  [FrameworkBundle] Test that ObjectNormalizer is registered

Author: fabpot

Form/ChoiceList/ORMQueryBuilderLoader.php

@@ -72,6 +72,13 @@ public function getEntitiesByIds($identifier, array $values)
             $values = array_values(array_filter($values, function ($v) {
                 return (string) $v === (string) (int) $v;
             }));
+        } elseif ('guid' === $metadata->getTypeOfField($identifier)) {
+            $parameterType = Connection::PARAM_STR_ARRAY;
+
+            // Like above, but we just filter out empty strings.
+            $values = array_values(array_filter($values, function ($v) {
+                return (string) $v !== '';
+            }));
         } else {
             $parameterType = Connection::PARAM_STR_ARRAY;
         }