Merge branch '6.4' into 7.0

* 6.4:
  fix merge
  fix syntax for PHP 7.2
  [Security] Fix Danish translations
  [Messenger] Improve deadlock handling on `ack()` and `reject()`
  [DomCrawler] Encode html entities only if nessecary
  [Serializer] reset backed_enum priority, and re-prioritise translatable
  [Validator] Accept `Stringable` in `ExecutionContext::build/addViolation()`
  [Serializer] Ignore when using #[Ignore] on a non-accessor
  [Filesystem] Strengthen the check of file permissions in `dumpFile`
  [Serializer] Fix XML scalar to object denormalization
  [HttpClient][EventSourceHttpClient] Fix consuming SSEs with \r\n separator

Author: xabbuh

Filesystem.php

@@ -662,7 +662,7 @@ public function dumpFile(string $filename, $content): void
                 throw new IOException(sprintf('Failed to write file "%s": ', $filename).self::$lastError, 0, null, $filename);
             }
 
-            self::box('chmod', $tmpFile, file_exists($filename) ? fileperms($filename) : 0666 & ~umask());
+            self::box('chmod', $tmpFile, @fileperms($filename) ?: 0666 & ~umask());
 
             $this->rename($tmpFile, $filename, true);
         } finally {