Merge branch '3.4' into 4.2

* 3.4: Catch empty deprecation.log silently (fixes symfony#31050)

Author: nicolas-grekas

src/Symfony/Bundle/DebugBundle/Resources/views/Profiler/icon.svg

@@ -127,9 +127,13 @@ private function getContainerDeprecationLogs()
  return [];
  }
 
+ if ('' === $logContent = trim(file_get_contents($file))) {
+ return [];
+ }
+
  $bootTime = filemtime($file);
  $logs = [];
- foreach (unserialize(file_get_contents($file)) as $log) {
+ foreach (unserialize($logContent) as $log) {
  $log['context'] = ['exception' => new SilencedErrorContext($log['type'], $log['file'], $log['line'], $log['trace'], $log['count'])];
  $log['timestamp'] = $bootTime;
  $log['priority'] = 100;