Allow empty response bodies for HTTP status 204 responses.

Author: Martin Brecht-Precht

Diff for: src/Response/JsonResponse.php

@@ -20,11 +20,16 @@ class JsonResponse extends AbstractResponse
 	 */
 	protected function setBody($body)
 	{
+		if ($this->getStatusCode() === 204) {
+			parent::setBody(null);
+			return $this;
+		}
 		$body = @json_decode($body, true);
 		if (is_null($body)) {
 			throw new HttpResponseException('Response data is no valid JSON string.');
 		}
-		return parent::setBody($body);
+		parent::setBody($body);
+		return $this;
 	}
 
 }