From 582fad70f547b7008495400b38c8b32c3412cd27 Mon Sep 17 00:00:00 2001
From: pukkandan <pukkandan.ytdlp@gmail.com>
Date: Mon, 8 Nov 2021 00:23:57 +0530
Subject: [PATCH] [outtmpl] Do not traverse `None` Closes #1585

---
 test/test_YoutubeDL.py | 1 +
 yt_dlp/utils.py        | 4 ++--
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/test/test_YoutubeDL.py b/test/test_YoutubeDL.py
index bd2d752e2..40c4169c8 100644
--- a/test/test_YoutubeDL.py
+++ b/test/test_YoutubeDL.py
@@ -737,6 +737,7 @@ class TestYoutubeDL(unittest.TestCase):
         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 75b4ed61b..875ab5e72 100644
--- 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 = ...