[youtube:tab] Follow redirect to regional channel (#2884)

Closes #2694
Authored by: coletdjnz

yt_dlp/extractor/youtube.py

@@ -3950,13 +3950,14 @@ class YoutubeTabBaseInfoExtractor(YoutubeBaseInfoExtractor):
             break
 
     @staticmethod
-    def _extract_selected_tab(tabs):
+    def _extract_selected_tab(tabs, fatal=True):
         for tab in tabs:
             renderer = dict_get(tab, ('tabRenderer', 'expandableTabRenderer')) or {}
             if renderer.get('selected') is True:
                 return renderer
         else:
-            raise ExtractorError('Unable to find selected tab')
+            if fatal:
+                raise ExtractorError('Unable to find selected tab')
 
     @classmethod
     def _extract_uploader(cls, data):
@@ -4229,7 +4230,7 @@ class YoutubeTabBaseInfoExtractor(YoutubeBaseInfoExtractor):
                     self.report_warning(error_to_compat_str(e))
                     break
 
-                if dict_get(data, ('contents', 'currentVideoEndpoint')):
+                if dict_get(data, ('contents', 'currentVideoEndpoint', 'onResponseReceivedActions')):
                     break
 
                 last_error = 'Incomplete yt initial data received'
@@ -4248,7 +4249,7 @@ class YoutubeTabBaseInfoExtractor(YoutubeBaseInfoExtractor):
             ytcfg = ytcfg or self.extract_ytcfg(item_id, webpage)
             # Reject webpage data if redirected to home page without explicitly requesting
             selected_tab = self._extract_selected_tab(traverse_obj(
-                data, ('contents', 'twoColumnBrowseResultsRenderer', 'tabs'), expected_type=list, default=[])) or {}
+                data, ('contents', 'twoColumnBrowseResultsRenderer', 'tabs'), expected_type=list, default=[]), fatal=False) or {}
             if (url != 'https://www.youtube.com/feed/recommended'
                     and selected_tab.get('tabIdentifier') == 'FEwhat_to_watch'  # Home page
                     and 'no-youtube-channel-redirect' not in self.get_param('compat_opts', [])):
@@ -4280,7 +4281,7 @@ class YoutubeTabBaseInfoExtractor(YoutubeBaseInfoExtractor):
                 return self._extract_response(
                     item_id=item_id, query=params, ep=ep, headers=headers,
                     ytcfg=ytcfg, fatal=fatal, default_client=default_client,
-                    check_get_keys=('contents', 'currentVideoEndpoint'))
+                    check_get_keys=('contents', 'currentVideoEndpoint', 'onResponseReceivedActions'))
         err_note = 'Failed to resolve url (does the playlist exist?)'
         if fatal:
             raise ExtractorError(err_note, expected=True)
@@ -4981,6 +4982,10 @@ class YoutubeTabIE(YoutubeTabBaseInfoExtractor):
             'skip_download': True,
             'extractor_args': {'youtubetab': {'skip': ['webpage']}}
         },
+    }, {
+        'note': 'non-standard redirect to regional channel',
+        'url': 'https://www.youtube.com/channel/UCwVVpHQ2Cs9iGJfpdFngePQ',
+        'only_matching': True
     }]
 
     @classmethod
@@ -5053,6 +5058,16 @@ class YoutubeTabIE(YoutubeTabBaseInfoExtractor):
 
         data, ytcfg = self._extract_data(url, item_id)
 
+        # YouTube may provide a non-standard redirect to the regional channel
+        # See: https://github.com/yt-dlp/yt-dlp/issues/2694
+        redirect_url = traverse_obj(
+            data, ('onResponseReceivedActions', ..., 'navigateAction', 'endpoint', 'commandMetadata', 'webCommandMetadata', 'url'), get_all=False)
+        if redirect_url and 'no-youtube-channel-redirect' not in compat_opts:
+            redirect_url = ''.join((
+                urljoin('https://www.youtube.com', redirect_url), mobj['tab'], mobj['post']))
+            self.to_screen(f'This playlist is likely not available in your region. Following redirect to regional playlist {redirect_url}')
+            return self.url_result(redirect_url, ie=YoutubeTabIE.ie_key())
+
         tabs = traverse_obj(data, ('contents', 'twoColumnBrowseResultsRenderer', 'tabs'), expected_type=list)
         if tabs:
             selected_tab = self._extract_selected_tab(tabs)