Merge branch '5.3' into 5.4

* 5.3:
  relax test assertions for forward-compatibility
  Added missing danish translation string
  [Messenger] Fix unwrapping the Postgres connection in DBAL 3
  Add Hungarian translation of new string
  improve greek translations
  [Messenger] fix: TypeError in PhpSerializer::encode()
  [Config] Fix files sorting in GlobResource
  Minor doc block wording change

Author: xabbuh

Tests/Transport/Serialization/PhpSerializerTest.php

@@ -53,6 +53,18 @@ public function testDecodingFailsWithBadFormat()
         ]);
     }
 
+    public function testDecodingFailsWithBadBase64Body()
+    {
+        $this->expectException(MessageDecodingFailedException::class);
+        $this->expectExceptionMessageMatches('/Could not decode/');
+
+        $serializer = new PhpSerializer();
+
+        $serializer->decode([
+            'body' => 'x',
+        ]);
+    }
+
     public function testDecodingFailsWithBadClass()
     {
         $this->expectException(MessageDecodingFailedException::class);

Transport/Serialization/PhpSerializer.php

@@ -58,6 +58,10 @@ public function encode(Envelope $envelope): array
 
     private function safelyUnserialize(string $contents)
     {
+        if ('' === $contents) {
+            throw new MessageDecodingFailedException('Could not decode an empty message using PHP serialization.');
+        }
+
         $signalingException = new MessageDecodingFailedException(sprintf('Could not decode message using PHP serialization: %s.', $contents));
         $prevUnserializeHandler = ini_set('unserialize_callback_func', self::class.'::handleUnserializeCallback');
         $prevErrorHandler = set_error_handler(function ($type, $msg, $file, $line, $context = []) use (&$prevErrorHandler, $signalingException) {