Fix: Prevent data duplication in TraceTelemetry with IncludeFormatted…

…Message.

sdk/monitor/Azure.Monitor.OpenTelemetry.Exporter/CHANGELOG.md

@@ -18,6 +18,11 @@
 the telemetry offline for retrying at a later time.
 ([#38832](https://github.com/Azure/azure-sdk-for-net/pull/38832))
 
+* Fixed an issue where `OriginalFormat` persisted in TraceTelemetry properties
+  with IncludeFormattedMessage enabled in OpenTelemetry LoggerProvider. This fix
+  prevents data duplication in message fields and properties.
+  ([#](https://github.com/Azure/azure-sdk-for-net/pull/))
+
 ### Other Changes
 
 * Update OpenTelemetry dependencies

sdk/monitor/Azure.Monitor.OpenTelemetry.Exporter/src/Internals/LogsHelper.cs

@@ -206,10 +206,6 @@ private static void ExtractProperties(ref string? message, IDictionary<string, s
                         {
                             message = item.Value.ToString();
                         }
-                        else
-                        {
-                            properties.Add("OriginalFormat", item.Value.ToString().Truncate(SchemaConstants.KVP_MaxValueLength) ?? "null");
-                        }
                     }
                     else
                     {

sdk/monitor/Azure.Monitor.OpenTelemetry.Exporter/tests/Azure.Monitor.OpenTelemetry.Exporter.Tests/LogsHelperTests.cs

@@ -55,13 +55,11 @@ public void MessageIsSetToExceptionMessage(bool parseStateValues)
 
             Assert.Equal("Test Exception", message);
 
-            Assert.True(properties.TryGetValue("OriginalFormat", out string value));
-            Assert.Equal(log, value);
             Assert.True(properties.TryGetValue("name", out string name));
             Assert.Equal("tomato", name);
             Assert.True(properties.TryGetValue("price", out string price));
             Assert.Equal("2.99", price);
-            Assert.Equal(3, properties.Count);
+            Assert.Equal(2, properties.Count);
         }
 
         [Fact]
@@ -87,13 +85,11 @@ public void MessageIsSetToFormattedMessageWhenIncludeFormattedMessageIsSet()
             var message = LogsHelper.GetMessageAndSetProperties(logRecords[0], properties);
 
             Assert.Equal("Hello from tomato 2.99.", message);
-            Assert.True(properties.TryGetValue("OriginalFormat", out string value));
-            Assert.Equal(log, value);
             Assert.True(properties.TryGetValue("name", out string name));
             Assert.Equal("tomato", name);
             Assert.True(properties.TryGetValue("price", out string price));
             Assert.Equal("2.99", price);
-            Assert.Equal(3, properties.Count);
+            Assert.Equal(2, properties.Count);
         }
 
         [Fact]

sdk/monitor/Azure.Monitor.OpenTelemetry.Exporter/tests/Azure.Monitor.OpenTelemetry.Exporter.Tests/TelemetryExceptionDataTests.cs

@@ -365,7 +365,6 @@ public void ValidateTelemetryExceptionData(LogLevel logLevel)
 
             Assert.Equal(2, exceptionData.Version);
             Assert.Equal(LogsHelper.GetSeverityLevel(logLevel), exceptionData.SeverityLevel);
-            Assert.Equal("Log Message", exceptionData.Properties["OriginalFormat"]);
             Assert.Empty(exceptionData.Measurements);
             Assert.Equal(typeof(Exception).FullName + " at UnknownMethod", exceptionData.ProblemId);
             Assert.Equal(1, exceptionData.Exceptions.Count);