fix(rtc): guard remote track event handlers against racing disconnect#758
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track_published, track_subscribed, track_unsubscribed and track_subscription_failed looked up the remote participant (and publication) with an unguarded dict access, raising KeyError when the participant had already been removed by a racing participant_disconnected or unpublish. This mirrors the defensive lookup already applied to track_unpublished in livekit#743, skipping the emit with a debug log when the entry is gone instead of letting _listen_task log a KeyError.
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Fixes #757
Problem
Room._on_room_eventraisesKeyErrorin thetrack_subscribedhandler (and its siblings) when the remote participant has already been removed fromself._remote_participantsby a racingparticipant_disconnectedor a duplicate event:It is swallowed by the
except Exception: logging.exception(...)in_listen_task, so it does not break the session, but it is logged as an error (and reported to error trackers as noise). It shows up most often with SIP participants, whose connect/disconnect ordering is racier than typical WebRTC clients.Fix
#743 already made
track_unpublisheddefensive for exactly this race. This PR applies the same pattern to the remaining handlers that still used an unguardedself._remote_participants[identity]:track_publishedtrack_subscribedtrack_unsubscribedtrack_subscription_failedEach now looks the participant (and, where applicable, the publication) up with
.get(...)and skips the emit with alogger.debugwhen the entry is already gone, matching the wording and behaviour of the existingtrack_unpublishedhandler.No behavioural change on the happy path; only the racing-disconnect case is affected.