From f954cf8bea9c6766e32a0d9cd0d7df5640344957 Mon Sep 17 00:00:00 2001
From: Kenneth Hsu <kennethhsu@gmail.com>
Date: Sat, 6 Jul 2019 12:45:48 -0700
Subject: [PATCH 1/4] Remove unused variable.

---
 Duplicati/Library/Main/Operation/BackupHandler.cs | 1 -
 1 file changed, 1 deletion(-)

diff --git a/Duplicati/Library/Main/Operation/BackupHandler.cs b/Duplicati/Library/Main/Operation/BackupHandler.cs
index 466f09d44..030189790 100644
--- a/Duplicati/Library/Main/Operation/BackupHandler.cs
+++ b/Duplicati/Library/Main/Operation/BackupHandler.cs
@@ -400,7 +400,6 @@ namespace Duplicati.Library.Main.Operation
                     using(var backendManager = new BackendManager(m_backendurl, m_options, m_result.BackendWriter, m_database))
                     using(var filesetvolume = new FilesetVolumeWriter(m_options, m_database.OperationTimestamp))
                     using(var stats = new Backup.BackupStatsCollector(m_result))
-                    using(var bk = new Common.BackendHandler(m_options, m_backendurl, db, stats, m_result.TaskReader))
                     // Keep a reference to these channels to avoid shutdown
                     using(var uploadtarget = ChannelManager.GetChannel(Backup.Channels.BackendRequest.ForWrite))
                     {

From bfa3c120e592782608860b6757b614c9ac64acf9 Mon Sep 17 00:00:00 2001
From: Kenneth Hsu <kennethhsu@gmail.com>
Date: Sat, 6 Jul 2019 12:50:37 -0700
Subject: [PATCH 2/4] Make Worker implement IDisposable.

This will allow the underlying Task and Backend to be disposed.
---
 .../Library/Main/Operation/Backup/BackendUploader.cs      | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/Duplicati/Library/Main/Operation/Backup/BackendUploader.cs b/Duplicati/Library/Main/Operation/Backup/BackendUploader.cs
index 97180f647..5c26539a4 100644
--- a/Duplicati/Library/Main/Operation/Backup/BackendUploader.cs
+++ b/Duplicati/Library/Main/Operation/Backup/BackendUploader.cs
@@ -443,7 +443,7 @@ namespace Duplicati.Library.Main.Operation.Backup
             }
         }
 
-        private class Worker
+        private class Worker : IDisposable
         {
             public Task Task;
             public IBackend Backend;
@@ -453,6 +453,12 @@ namespace Duplicati.Library.Main.Operation.Backup
                 Backend = backend;
                 Task = Task.FromResult(true);
             }
+
+            public void Dispose()
+            {
+                this.Task?.Dispose();
+                this.Backend?.Dispose();
+            }
         }
     }
 }

From c1497929738eebf25b044bf8fefcdaac33f6c900 Mon Sep 17 00:00:00 2001
From: Kenneth Hsu <kennethhsu@gmail.com>
Date: Sat, 6 Jul 2019 13:34:14 -0700
Subject: [PATCH 3/4] Dispose Backends after upload operations.

This addresses issue #3808.
---
 .../Main/Operation/Backup/BackendUploader.cs       | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/Duplicati/Library/Main/Operation/Backup/BackendUploader.cs b/Duplicati/Library/Main/Operation/Backup/BackendUploader.cs
index 5c26539a4..2925aa141 100644
--- a/Duplicati/Library/Main/Operation/Backup/BackendUploader.cs
+++ b/Duplicati/Library/Main/Operation/Backup/BackendUploader.cs
@@ -181,7 +181,9 @@ namespace Duplicati.Library.Main.Operation.Backup
                                     ExceptionDispatchInfo.Capture(finishedTask.Exception).Throw();
                                 }
 
-                                workers.RemoveAll(w => w.Task == finishedTask);
+                                Worker finishedWorker = workers.Single(w => w.Task == finishedTask);
+                                workers.Remove(finishedWorker);
+                                finishedWorker.Dispose();
                             }
                             
                             flush.SetFlushed(lastSize);
@@ -212,7 +214,14 @@ namespace Duplicati.Library.Main.Operation.Backup
                     {
                         await Task.WhenAll(workers.Select(w => w.Task));
                     }
-                    catch { /* As we are cancelling all threads we do not need to alert the user to any of these exceptions */ }
+                    catch
+                    {
+                        /* As we are cancelling all threads we do not need to alert the user to any of these exceptions */
+                    }
+                    finally
+                    {
+                        workers.ForEach(w => w.Dispose());
+                    }
                     throw;
                 }
 
@@ -224,6 +233,7 @@ namespace Duplicati.Library.Main.Operation.Backup
                 finally
                 {
                     m_stats.SetBlocking(false);
+                    workers.ForEach(w => w.Dispose());
                 }
             });
         }

From 7fd815b56e59308f3cdddeb50c61a39f35b38e35 Mon Sep 17 00:00:00 2001
From: Kenneth Hsu <kennethhsu@gmail.com>
Date: Sat, 6 Jul 2019 15:34:46 -0700
Subject: [PATCH 4/4] Simplify comment.

---
 Duplicati/Library/Main/Operation/Backup/BackendUploader.cs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Duplicati/Library/Main/Operation/Backup/BackendUploader.cs b/Duplicati/Library/Main/Operation/Backup/BackendUploader.cs
index 2925aa141..65ca193b2 100644
--- a/Duplicati/Library/Main/Operation/Backup/BackendUploader.cs
+++ b/Duplicati/Library/Main/Operation/Backup/BackendUploader.cs
@@ -216,7 +216,7 @@ namespace Duplicati.Library.Main.Operation.Backup
                     }
                     catch
                     {
-                        /* As we are cancelling all threads we do not need to alert the user to any of these exceptions */
+                        // As we are cancelling all threads we do not need to alert the user to any of these exceptions.
                     }
                     finally
                     {