bpo-43564: preserve original error in args of FTP URLError

Carl Meyer · Carl Meyer · commit 6e00df67a827 · 2021-03-19T14:23:16.000-07:00
diff --git a/Lib/urllib/request.py b/Lib/urllib/request.py
@@ -1579,7 +1579,7 @@ def ftp_open(self, req):
             headers = email.message_from_string(headers)
             return addinfourl(fp, headers, req.full_url)
         except ftplib.all_errors as exp:
-            exc = URLError('ftp error: %r' % exp)
+            exc = URLError(exp)
             raise exc.with_traceback(sys.exc_info()[2])
 
     def connect_ftp(self, user, passwd, host, port, dirs, timeout):
