From b1bf7698aa476e96801b95ecb5d95f9d71230abc Mon Sep 17 00:00:00 2001
From: Philip Schill <philip.schill@gmx.de>
Date: Fri, 29 Jan 2021 17:37:47 +0100
Subject: [PATCH] The topic filter comparer now checks for e.g. "foo/" matching
 "foo/#".

---
 Source/MQTTnet/Server/MqttTopicFilterComparer.cs      | 7 +++++++
 Tests/MQTTnet.Core.Tests/TopicFilterComparer_Tests.cs | 6 ++++++
 2 files changed, 13 insertions(+)

diff --git a/Source/MQTTnet/Server/MqttTopicFilterComparer.cs b/Source/MQTTnet/Server/MqttTopicFilterComparer.cs
index 4ba614d..5b104b4 100644
--- a/Source/MQTTnet/Server/MqttTopicFilterComparer.cs
+++ b/Source/MQTTnet/Server/MqttTopicFilterComparer.cs
@@ -31,6 +31,13 @@ namespace MQTTnet.Server
                         {
                             return true;
                         }
+                        // Check for e.g. foo/ matching foo/#
+                        if (sPos == sLen - 2
+                                && filter[sPos] == LevelSeparator
+                                && filter[sPos + 1] == MultiLevelWildcard)
+                        {
+                            return true;
+                        }
                     }
 
                     sPos++;
diff --git a/Tests/MQTTnet.Core.Tests/TopicFilterComparer_Tests.cs b/Tests/MQTTnet.Core.Tests/TopicFilterComparer_Tests.cs
index 35e8504..b1de7c8 100644
--- a/Tests/MQTTnet.Core.Tests/TopicFilterComparer_Tests.cs
+++ b/Tests/MQTTnet.Core.Tests/TopicFilterComparer_Tests.cs
@@ -54,6 +54,12 @@ namespace MQTTnet.Tests
             CompareAndAssert("A/B/C/D", "A/C/#", false);
         }
 
+        [TestMethod]
+        public void TopicFilterComparer_EndMultipleLevelsWildcardMatchEmptyLevel()
+        {
+            CompareAndAssert("A/", "A/#", true);
+        }
+
         [TestMethod]
         public void TopicFilterComparer_AllLevelsWildcardMatch()
         {