[downloader/external] add _argless_option for option without arguments

youtube_dl/downloader/external.py

@@ -49,8 +49,6 @@ class ExternalFD(FileDownloader):
         param = self.params.get(param)
         if param is None or param is False:
             return []
-        if isinstance(param, bool):
-            return [command_option]
         return [command_option, param]
 
     def _bool_option(self, command_option, param, true_value='true', false_value='false', separator=None):
@@ -61,6 +59,10 @@ class ExternalFD(FileDownloader):
             return [command_option + separator + (true_value if param else false_value)]
         return [command_option, true_value if param else false_value]
 
+    def _argless_option(self, command_option, param, expected_value=True):
+        param = self.params.get(param)
+        return [command_option] if param == expected_value else []
+
     def _configuration_args(self, default=[]):
         ex_args = self.params.get('external_downloader_args')
         if ex_args is None:
@@ -89,7 +91,7 @@ class CurlFD(ExternalFD):
             cmd += ['--header', '%s: %s' % (key, val)]
         cmd += self._option('--interface', 'source_address')
         cmd += self._option('--proxy', 'proxy')
-        cmd += self._option('--insecure', 'nocheckcertificate')
+        cmd += self._argless_option('--insecure', 'nocheckcertificate')
         cmd += self._configuration_args()
         cmd += ['--', info_dict['url']]
         return cmd
@@ -112,7 +114,7 @@ class WgetFD(ExternalFD):
             cmd += ['--header', '%s: %s' % (key, val)]
         cmd += self._option('--bind-address', 'source_address')
         cmd += self._option('--proxy', 'proxy')
-        cmd += self._option('--no-check-certificate', 'nocheckcertificate')
+        cmd += self._argless_option('--no-check-certificate', 'nocheckcertificate')
         cmd += self._configuration_args()
         cmd += ['--', info_dict['url']]
         return cmd