From 5fa8e58f8d1dfa60fea74dbfc48632163d39d4ae Mon Sep 17 00:00:00 2001
From: Achim Schaefer <achim_schaefer@gmx.de>
Date: Thu, 5 Nov 2020 15:49:48 +0100
Subject: [PATCH] Bugfix issue #3920

only "best-effort" and "realtime" allow a priotity level
"none" and "idle" have no prioity level
---
 Duplicati/Library/Main/ProcessController.cs | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/Duplicati/Library/Main/ProcessController.cs b/Duplicati/Library/Main/ProcessController.cs
index cda5f0866..c3f301913 100755
--- a/Duplicati/Library/Main/ProcessController.cs
+++ b/Duplicati/Library/Main/ProcessController.cs
@@ -208,12 +208,14 @@ namespace Duplicati.Library.Main
                     if (string.Equals(ioclass, "idle", StringComparison.OrdinalIgnoreCase))
                     {
                         m_originalNiceClass = 3;
+                        // Only allowed for "best-effort" and "realtime"
                         m_originalNiceLevel = -1;
                     }
                     else if (string.Equals(ioclass, "none", StringComparison.OrdinalIgnoreCase))
                     {
                         m_originalNiceClass = 0;
-                        m_originalNiceLevel = int.Parse(results.Last());
+                        // Only allowed for "best-effort" and "realtime"
+                        m_originalNiceLevel = -1; 
                     }
                     else if (string.Equals(ioclass, "best-effort", StringComparison.OrdinalIgnoreCase))
                     {