Merge 0a6117341a5fb293ebce82a069d8721c2d37d723 into 3eb8d22ddb8982ca4fb56bb7a8d6517538bf14c6

Co-authored-by: dirkf <fieldhouse@gmx.net>

youtube_dl/extractor/extractors.py

@@ -848,14 +848,13 @@ from .nowness import (
 from .noz import NozIE
 from .npo import (
     AndereTijdenIE,
+    BNNVaraIE,
     NPOIE,
-    NPOLiveIE,
+    ONIE,
-    NPORadioIE,
-    NPORadioFragmentIE,
     SchoolTVIE,
     HetKlokhuisIE,
     VPROIE,
-    WNLIE,
+    ZAPPIE,
 )
 from .npr import NprIE
 from .nrk import (

youtube_dl/jsinterp.py

@@ -686,6 +686,8 @@ class JSInterpreter(object):
             raise self.Exception('Cannot get index {idx!r:.100}'.format(**locals()), expr=repr(obj), cause=e)
 
     def _dump(self, obj, namespace):
+        if obj is JS_Undefined:
+            return 'undefined'
         try:
             return json.dumps(obj)
         except TypeError: