From 087ef1463f35ba0d807fd58d25428c8befb2f9bd Mon Sep 17 00:00:00 2001
From: Kenneth Skovhede <kenneth@duplicati.com>
Date: Wed, 5 Nov 2025 09:16:50 +0100
Subject: [PATCH] Merge pull request #6605 from
 carljohnsen/bugfix/remote-sync-seek-on-nonseekstream

Bugfix/Remote Synchronization tool seek on non-seekable stream
---
 Tools/RemoteSynchronization/LightWeightBackendManager.cs | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/Tools/RemoteSynchronization/LightWeightBackendManager.cs b/Tools/RemoteSynchronization/LightWeightBackendManager.cs
index 25768872d..72994d212 100644
--- a/Tools/RemoteSynchronization/LightWeightBackendManager.cs
+++ b/Tools/RemoteSynchronization/LightWeightBackendManager.cs
@@ -271,9 +271,12 @@ namespace RemoteSynchronization
                     Dispose(); // Dispose current backend and streaming backend.
 
                     // Reset the stream, as it's in a potentially faulty state.
-                    stream?.Seek(0, SeekOrigin.Begin);
-                    if (resetStream)
-                        stream?.SetLength(0);
+                    if (stream != null && stream.CanSeek)
+                    {
+                        stream.Seek(0, SeekOrigin.Begin);
+                        if (resetStream)
+                            stream.SetLength(0);
+                    }
 
                     // Try to see if we can recover from the error.
                     await TryRecoverFromException(ex, token).ConfigureAwait(false);