From 356e0f101a05264d3f50336b46c15aa4ff736cea Mon Sep 17 00:00:00 2001
From: Jason Dove <1695733+jasongdove@users.noreply.github.com>
Date: Tue, 13 Feb 2024 10:01:02 -0600
Subject: [PATCH] fix edge case where channel would fail to start (#1611)

---
 .../FFmpeg/FFmpegSegmenterService.cs          | 21 +++++++++++++++++--
 ErsatzTV/Controllers/IptvController.cs        |  2 +-
 2 files changed, 20 insertions(+), 3 deletions(-)

diff --git a/ErsatzTV.Core/FFmpeg/FFmpegSegmenterService.cs b/ErsatzTV.Core/FFmpeg/FFmpegSegmenterService.cs
index 69913744..b90c1d1c 100644
--- a/ErsatzTV.Core/FFmpeg/FFmpegSegmenterService.cs
+++ b/ErsatzTV.Core/FFmpeg/FFmpegSegmenterService.cs
@@ -17,8 +17,25 @@ public class FFmpegSegmenterService(ILogger<FFmpegSegmenterService> logger) : IF
 
     public bool TryAddWorker(string channelNumber, IHlsSessionWorker worker)
     {
-        bool result = _sessionWorkers.TryAdd(channelNumber, worker);
-
+        var result = false;
+        
+        // check for worker
+        if (TryGetWorker(channelNumber, out IHlsSessionWorker existing))
+        {
+            // if worker is null, pretend we added it
+            if (existing is null)
+            {
+                result = true;
+            }
+            
+            // if worker is not null, we cannot add one (so result should stay false)
+        }
+        else
+        {
+            // worker does not exist, so try adding a null one
+            result = _sessionWorkers.TryAdd(channelNumber, worker);
+        }
+        
         if (result)
         {
             OnWorkersChanged?.Invoke(this, EventArgs.Empty);
diff --git a/ErsatzTV/Controllers/IptvController.cs b/ErsatzTV/Controllers/IptvController.cs
index 3d5b8dde..2f902c55 100644
--- a/ErsatzTV/Controllers/IptvController.cs
+++ b/ErsatzTV/Controllers/IptvController.cs
@@ -142,7 +142,7 @@ public class IptvController : ControllerBase
     {
         // _logger.LogDebug("Checking for session worker for channel {Channel}", channelNumber);
 
-        if (_ffmpegSegmenterService.TryGetWorker(channelNumber, out IHlsSessionWorker worker))
+        if (_ffmpegSegmenterService.TryGetWorker(channelNumber, out IHlsSessionWorker worker) && worker is not null)
         {
             // _logger.LogDebug("Trimming playlist for channel {Channel}", channelNumber);