[outtmpl] Do not traverse `None`

Closes #1585

diff --git a/test/test_YoutubeDL.py b/test/test_YoutubeDL.py
index bd2d752e2571de8f8890a54402ddc8d5a3f43074..40c4169c8bda07130d75c8bd816826b997c9f746 100644 (file)
--- a/test/test_YoutubeDL.py
+++ b/test/test_YoutubeDL.py
@@ -737,6 +737,7 @@ def expect_same_infodict(out):
         test(NA_TEST_OUTTMPL, 'NA-NA-def-1234.mp4')
         test(NA_TEST_OUTTMPL, 'none-none-def-1234.mp4', outtmpl_na_placeholder='none')
         test(NA_TEST_OUTTMPL, '--def-1234.mp4', outtmpl_na_placeholder='')
+        test('%(non_existent.0)s', 'NA')
 
         # String formatting
         FMT_TEST_OUTTMPL = '%%(height)%s.%%(ext)s'

diff --git a/yt_dlp/utils.py b/yt_dlp/utils.py
index 75b4ed61b6d47c19e503d106ffc9b1876f782bb9..875ab5e72950395a3178f3190dc99f48f417ac35 100644 (file)
--- a/yt_dlp/utils.py
+++ b/yt_dlp/utils.py
@@ -6442,10 +6442,10 @@ def traverse_obj(
 
     def _traverse_obj(obj, path, _current_depth=0):
         nonlocal depth
-        if obj is None:
-            return None
         path = tuple(variadic(path))
         for i, key in enumerate(path):
+            if obj is None:
+                return None
             if isinstance(key, (list, tuple)):
                 obj = [_traverse_obj(obj, sub_key, _current_depth) for sub_key in key]
                 key = ...