Do not read configuration files if explicit arguments are given by a host program (#792)

youtube_dl/__init__.py

@@ -47,7 +47,7 @@ from .FileDownloader import *
 from .InfoExtractors import gen_extractors
 from .PostProcessor import *
 
-def parseOpts(arguments):
+def parseOpts(overrideArguments=None):
     def _readOptions(filename_bytes):
         try:
             optionf = open(filename_bytes)
@@ -300,6 +300,11 @@ def parseOpts(arguments):
     parser.add_option_group(authentication)
     parser.add_option_group(postproc)
 
+    if overrideArguments is not None:
+        opts, args = parser.parse_args(overrideArguments)
+        if opts.verbose:
+            print(u'[debug] Override config: ' + repr(overrideArguments))
+    else:
         xdg_config_home = os.environ.get('XDG_CONFIG_HOME')
         if xdg_config_home:
             userConfFile = os.path.join(xdg_config_home, 'youtube-dl.conf')
@@ -308,7 +313,7 @@ def parseOpts(arguments):
         systemConf = _readOptions('/etc/youtube-dl.conf')
         userConf = _readOptions(userConfFile)
         commandLineConf = sys.argv[1:] 
-    argv = (systemConf + userConf + commandLineConf) if not arguments else arguments
+        argv = systemConf + userConf + commandLineConf
         opts, args = parser.parse_args(argv)
 
     if opts.verbose: