Fix logging issues.

Tests/MQTTnet.Benchmarks/LoggerBenchmark.cs

@@ -16,7 +16,7 @@ namespace MQTTnet.Benchmarks
         [GlobalSetup]
         public void Setup()
         {
-            _logger = new MqttNetLogger("1");
+            _logger = new MqttNetLogger();
             _childLogger = _logger.CreateChildLogger("child");
 
             MqttNetGlobalLogger.LogMessagePublished += OnLogMessagePublished;

Tests/MQTTnet.Core.Tests/MqttFactory_Tests.cs

@@ -24,7 +24,7 @@ namespace MQTTnet.Tests
             //var globalLogCount = 0;
             var localLogCount = 0;
 
-            var logger = new MqttNetLogger(logId);
+            var logger = new MqttNetLogger(null, logId);
 
             // TODO: This is commented out because it is affected by other tests.
             //// we have a theoretical bug here if a concurrent test is also logging

Tests/MQTTnet.Core.Tests/MqttNetLogger_Tests.cs

@@ -46,5 +46,22 @@ namespace MQTTnet.Tests
 
             Assert.AreEqual(4, logMessagesCount);
         }
+
+        [TestMethod]
+        public void Set_Custom_Log_ID()
+        {
+            var logger = new MqttNetLogger(null, "logId");
+            var childLogger = logger.CreateChildLogger("Source1");
+
+            logger.LogMessagePublished += (s, e) =>
+            {
+                Assert.AreEqual("logId", e.LogMessage.LogId);
+            };
+
+            childLogger.Verbose("Verbose");
+            childLogger.Info("Info");
+            childLogger.Warning(null, "Warning");
+            childLogger.Error(null, "Error");
+        }
     }
 }