Merge branch '5.3' into 5.4

* 5.3:
  [Notifier] Allow passing a previous throwable to exceptions

Author: OskarStark

Exception/TransportException.php

@@ -21,7 +21,7 @@ class TransportException extends RuntimeException implements TransportExceptionI
     private $response;
     private $debug = '';
 
-    public function __construct(string $message, ResponseInterface $response, int $code = 0, \Exception $previous = null)
+    public function __construct(string $message, ResponseInterface $response, int $code = 0, \Throwable $previous = null)
     {
         $this->response = $response;
         $this->debug .= $response->getInfo('debug') ?? '';

Exception/UnsupportedSchemeException.php

@@ -169,7 +169,7 @@ class UnsupportedSchemeException extends LogicException
     /**
      * @param string[] $supported
      */
-    public function __construct(Dsn $dsn, string $name = null, array $supported = [])
+    public function __construct(Dsn $dsn, string $name = null, array $supported = [], \Throwable $previous = null)
     {
         $provider = $dsn->getScheme();
         if (false !== $pos = strpos($provider, '+')) {
@@ -187,6 +187,6 @@ public function __construct(Dsn $dsn, string $name = null, array $supported = []
             $message .= sprintf('; supported schemes for notifier "%s" are: "%s"', $name, implode('", "', $supported));
         }
 
-        parent::__construct($message.'.');
+        parent::__construct($message.'.', 0, $previous);
     }
 }