From 56c3a3652d859007e2a01ae9a27b08df2dc7e333 Mon Sep 17 00:00:00 2001
From: "REDMOND\\viyarr" <viyarr@microsoft.com>
Date: Tue, 17 Jun 2025 11:54:06 -0700
Subject: [PATCH] Fixing the case null session state was being set as empty
 byte array. They are not the same. Setting session state to null properly
 cleans up session state in service bus.

---
 .../Common/Abstraction/ServiceBusAbstraction.cs               | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/DurableTask.ServiceBus/Common/Abstraction/ServiceBusAbstraction.cs b/src/DurableTask.ServiceBus/Common/Abstraction/ServiceBusAbstraction.cs
index 779f95c9d..c8d97b205 100644
--- a/src/DurableTask.ServiceBus/Common/Abstraction/ServiceBusAbstraction.cs
+++ b/src/DurableTask.ServiceBus/Common/Abstraction/ServiceBusAbstraction.cs
@@ -140,7 +140,9 @@ public async Task SetStateAsync(byte[] sessionState)
         {
             if (sessionState == null)
             {
-                await this.sessionReceiver.SetSessionStateAsync(new BinaryData(new byte[] { }));
+                // Setting session state to null is equivalent to deleting session state.
+                // Setting session state to empty byte array is not equivalent to deleting session state.
+                await this.sessionReceiver.SetSessionStateAsync(null);
             }
             else
             {