fix(download): skip deleted channel during playlist refresh

When a channel is deleted between being added to the channel queue and
post-processing running, _add_channel_playlists called channel.get_overwrites()
on a None json_data, raising AttributeError and aborting the whole
post-processing task. The same problem affected playlists/comments for every
other channel in the queue.

Skip the missing channel cleanly with a log line, mirroring how
refresh_playlist already handles failed playlist imports (#1032).

Closes #1103

backend/download/src/yt_dlp_handler.py

@@ -428,6 +428,10 @@ class DownloadPostProcess(DownloaderBase):
 
             channel = YoutubeChannel(channel_id)
             channel.get_from_es()
+            if not channel.json_data:
+                print(f"{channel_id}: skip deleted channel for playlist refresh")
+                continue
+
             overwrites = channel.get_overwrites()
             if overwrites.get("index_playlists"):
                 channel.get_all_playlists()

backend/download/tests/test_src/test_add_channel_playlists.py

@@ -0,0 +1,144 @@
+"""tests for _add_channel_playlists handling of deleted channels"""
+
+from unittest.mock import patch
+
+import pytest
+from download.src.yt_dlp_handler import DownloadPostProcess
+
+
+class FakeChannelQueue:
+    """minimal queue stand-in returning a fixed sequence of (channel_id, idx) pairs"""
+
+    def __init__(self, items):
+        self._items = list(items)
+
+    def get_next(self):
+        if not self._items:
+            return None, None
+        return self._items.pop(0)
+
+
+class FakePlaylistQueue:
+    """records add_list calls, returns nothing on get_next"""
+
+    def __init__(self):
+        self.added_lists: list[list] = []
+
+    def get_next(self):
+        return None, None
+
+    def add_list(self, to_add):
+        if to_add:
+            self.added_lists.append(list(to_add))
+
+
+@pytest.fixture
+def handler():
+    """DownloadPostProcess with __init__ bypassed — _add_channel_playlists doesn't touch config or task"""
+
+    instance = DownloadPostProcess.__new__(DownloadPostProcess)
+    instance.task = None
+    return instance
+
+
+def test_skips_channel_when_json_data_missing(handler, capsys):
+    """regression for #1103: channel deleted from ES must not raise AttributeError"""
+
+    channel_id = "UCdeleted-channel-1"
+    fake_channel_q = FakeChannelQueue([(channel_id, 0)])
+
+    class FakeDeletedChannel:
+        youtube_id = channel_id
+        json_data = None
+
+        def get_from_es(self):
+            pass
+
+        def get_overwrites(self):
+            raise AssertionError(
+                "get_overwrites must not be called when json_data is None"
+            )
+
+        def get_all_playlists(self):
+            raise AssertionError(
+                "get_all_playlists must not be called when json_data is None"
+            )
+
+    with patch(
+        "download.src.yt_dlp_handler.RedisQueue",
+        side_effect=[fake_channel_q, FakePlaylistQueue()],
+    ), patch(
+        "download.src.yt_dlp_handler.YoutubeChannel",
+        return_value=FakeDeletedChannel(),
+    ):
+        handler._add_channel_playlists()
+
+    captured = capsys.readouterr()
+    assert "skip deleted channel" in captured.out
+    assert channel_id in captured.out
+
+
+def test_processes_channel_with_playlists_enabled(handler):
+    """a live channel with index_playlists=true should add its playlists"""
+
+    channel_id = "UClive-channel-2"
+    fake_channel_q = FakeChannelQueue([(channel_id, 0)])
+    fake_playlist_q = FakePlaylistQueue()
+
+    class FakeLiveChannel:
+        youtube_id = channel_id
+        json_data = {"channel_overwrites": {"index_playlists": True}}
+        all_playlists = [("PLplaylistA", "Playlist A"), ("PLplaylistB", "Playlist B")]
+
+        def get_from_es(self):
+            pass
+
+        def get_overwrites(self):
+            return self.json_data["channel_overwrites"]
+
+        def get_all_playlists(self):
+            pass
+
+    with patch(
+        "download.src.yt_dlp_handler.RedisQueue",
+        side_effect=[fake_channel_q, fake_playlist_q],
+    ), patch(
+        "download.src.yt_dlp_handler.YoutubeChannel",
+        return_value=FakeLiveChannel(),
+    ):
+        handler._add_channel_playlists()
+
+    assert fake_playlist_q.added_lists == [["PLplaylistA", "PLplaylistB"]]
+
+
+def test_skips_channel_with_playlists_disabled(handler):
+    """a live channel with index_playlists missing/false must add nothing"""
+
+    channel_id = "UCquiet-channel-3"
+    fake_channel_q = FakeChannelQueue([(channel_id, 0)])
+    fake_playlist_q = FakePlaylistQueue()
+
+    class FakeQuietChannel:
+        youtube_id = channel_id
+        json_data = {"channel_overwrites": {}}
+        all_playlists = []
+
+        def get_from_es(self):
+            pass
+
+        def get_overwrites(self):
+            return self.json_data["channel_overwrites"]
+
+        def get_all_playlists(self):
+            pass
+
+    with patch(
+        "download.src.yt_dlp_handler.RedisQueue",
+        side_effect=[fake_channel_q, fake_playlist_q],
+    ), patch(
+        "download.src.yt_dlp_handler.YoutubeChannel",
+        return_value=FakeQuietChannel(),
+    ):
+        handler._add_channel_playlists()
+
+    assert fake_playlist_q.added_lists == []