From 713b4cd18f00556771af8cfdd9cea6cc1a09e948 Mon Sep 17 00:00:00 2001
From: bashonly <88596187+bashonly@users.noreply.github.com>
Date: Tue, 23 Jul 2024 16:25:49 -0500
Subject: [PATCH] [ie/youtube] Fix `n` function name extraction for player
 `3400486c` (#10542)

Authored by: bashonly
---
 test/test_youtube_signature.py | 4 ++++
 yt_dlp/extractor/youtube.py    | 9 ++++++++-
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/test/test_youtube_signature.py b/test/test_youtube_signature.py
index a14bef511e..ae167d16d4 100644
--- a/test/test_youtube_signature.py
+++ b/test/test_youtube_signature.py
@@ -171,6 +171,10 @@ _NSIG_TESTS = [
         'https://www.youtube.com/s/player/b22ef6e7/player_ias.vflset/en_US/base.js',
         'b6HcntHGkvBLk_FRf', 'kNPW6A7FyP2l8A',
     ),
+    (
+        'https://www.youtube.com/s/player/3400486c/player_ias.vflset/en_US/base.js',
+        'lL46g3XifCKUZn1Xfw', 'z767lhet6V2Skl',
+    ),
 ]
 
 
diff --git a/yt_dlp/extractor/youtube.py b/yt_dlp/extractor/youtube.py
index 53aca3816b..7364e8a2eb 100644
--- a/yt_dlp/extractor/youtube.py
+++ b/yt_dlp/extractor/youtube.py
@@ -3131,7 +3131,14 @@ class YoutubeIE(YoutubeBaseInfoExtractor):
 
     def _extract_n_function_name(self, jscode):
         funcname, idx = self._search_regex(
-            r'''(?x)(?:\.get\("n"\)\)&&\(b=|b=String\.fromCharCode\(110\),c=a\.get\(b\)\)&&\(c=)
+            r'''(?x)
+            (?:
+                \.get\("n"\)\)&&\(b=|
+                (?:
+                    b=String\.fromCharCode\(110\)|
+                    ([a-zA-Z0-9$.]+)&&\(b="nn"\[\+\1\]
+                ),c=a\.get\(b\)\)&&\(c=
+            )
             (?P<nfunc>[a-zA-Z0-9$]+)(?:\[(?P<idx>\d+)\])?\([a-zA-Z0-9]\)''',
             jscode, 'Initial JS player n function name', group=('nfunc', 'idx'))
         if not idx: