Fix live stream consumer leak when PositionTicks is negative

When a stalled HLS client sends ReportPlaybackStopped with a negative
PositionTicks (e.g. HLS.js reporting position on buffer stall), the
ArgumentOutOfRangeException was thrown before GetSession was called,
causing CloseLiveStreamIfNeededAsync to never run. This left the
ILiveStream.ConsumerCount permanently incremented, permanently holding
a tuner open with no active viewer.

Fix by acquiring the session and performing live stream cleanup before
throwing the validation exception, so tuner resources are always freed
even when playback reporting fails with invalid position data.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

1 files changed, 11 insertions, 4 deletions

diff --git a/Emby.Server.Implementations/Session/SessionManager.cs b/Emby.Server.Implementations/Session/SessionManager.cs
index 8e14f5bdf4..7e13e17eb6 100644
--- a/Emby.Server.Implementations/Session/SessionManager.cs
+++ b/Emby.Server.Implementations/Session/SessionManager.cs
@@ -1025,15 +1025,22 @@ namespace Emby.Server.Implementations.Session
 
             ArgumentNullException.ThrowIfNull(info);
 
+            var session = GetSession(info.SessionId);
+
+            session.StopAutomaticProgress();
+
             if (info.PositionTicks.HasValue && info.PositionTicks.Value < 0)
             {
+                // Ensure live stream is cleaned up before throwing, to prevent tuner
+                // resource leaks when stalled clients report a negative PositionTicks.
+                if (!string.IsNullOrEmpty(info.LiveStreamId))
+                {
+                    await CloseLiveStreamIfNeededAsync(info.LiveStreamId, session.Id).ConfigureAwait(false);
+                }
+
                 throw new ArgumentOutOfRangeException(nameof(info), "The PlaybackStopInfo's PositionTicks was negative.");
             }
 
-            var session = GetSession(info.SessionId);
-
-            session.StopAutomaticProgress();
-
             var libraryItem = info.ItemId.IsEmpty()
                 ? null
                 : GetNowPlayingItem(session, info.ItemId);