From b1f1b2cbc77113caf0d1d50325c451ae6189d1eb Mon Sep 17 00:00:00 2001
From: jbhensley <jbhensley@users.noreply.github.com>
Date: Fri, 12 Oct 2018 17:25:19 -0700
Subject: [PATCH] Fix "Non-static method requires a target" caused by trying to
 access the HasValue property of a nullable type through reflection when the
 value is null. (#20350)

Signed-off-by: dotnet-bot <dotnet-bot@microsoft.com>
---
 .../Diagnostics/Tracing/TraceLogging/SimpleTypeInfos.cs  | 8 ++++----
 .../Tracing/TraceLogging/TraceLoggingDataCollector.cs    | 9 +++++++++
 2 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/src/Common/src/CoreLib/System/Diagnostics/Tracing/TraceLogging/SimpleTypeInfos.cs b/src/Common/src/CoreLib/System/Diagnostics/Tracing/TraceLogging/SimpleTypeInfos.cs
index e0a937479037..dc714d860ec8 100644
--- a/src/Common/src/CoreLib/System/Diagnostics/Tracing/TraceLogging/SimpleTypeInfos.cs
+++ b/src/Common/src/CoreLib/System/Diagnostics/Tracing/TraceLogging/SimpleTypeInfos.cs
@@ -269,7 +269,6 @@ public override void WriteData(TraceLoggingDataCollector collector, PropertyValu
     internal sealed class NullableTypeInfo : TraceLoggingTypeInfo
     {
         private readonly TraceLoggingTypeInfo valueInfo;
-        private readonly Func<PropertyValue, PropertyValue> hasValueGetter;
         private readonly Func<PropertyValue, PropertyValue> valueGetter;
 
         public NullableTypeInfo(Type type, List<Type> recursionCheck)
@@ -278,7 +277,6 @@ public NullableTypeInfo(Type type, List<Type> recursionCheck)
             var typeArgs = type.GenericTypeArguments;
             Debug.Assert(typeArgs.Length == 1);
             this.valueInfo = TraceLoggingTypeInfo.GetInstance(typeArgs[0], recursionCheck);
-            this.hasValueGetter = PropertyValue.GetPropertyGetter(type.GetTypeInfo().GetDeclaredProperty("HasValue"));
             this.valueGetter = PropertyValue.GetPropertyGetter(type.GetTypeInfo().GetDeclaredProperty("Value"));
         }
 
@@ -294,9 +292,11 @@ public override void WriteMetadata(
 
         public override void WriteData(TraceLoggingDataCollector collector, PropertyValue value)
         {
-            var hasValue = hasValueGetter(value);
+            // It's not currently possible to get the HasValue property of a nullable type through reflection when the
+            // value is null. Instead, we simply check that the nullable is not null.
+            var hasValue = value.ReferenceValue != null;
             collector.AddScalar(hasValue);
-            var val = hasValue.ScalarValue.AsBoolean ? valueGetter(value) : valueInfo.PropertyValueFactory(Activator.CreateInstance(valueInfo.DataType));
+            var val = hasValue ? valueGetter(value) : valueInfo.PropertyValueFactory(Activator.CreateInstance(valueInfo.DataType));
             this.valueInfo.WriteData(collector, val);
         }
     }
diff --git a/src/Common/src/CoreLib/System/Diagnostics/Tracing/TraceLogging/TraceLoggingDataCollector.cs b/src/Common/src/CoreLib/System/Diagnostics/Tracing/TraceLogging/TraceLoggingDataCollector.cs
index f6d0a59aa623..c6f89c8784e6 100644
--- a/src/Common/src/CoreLib/System/Diagnostics/Tracing/TraceLogging/TraceLoggingDataCollector.cs
+++ b/src/Common/src/CoreLib/System/Diagnostics/Tracing/TraceLogging/TraceLoggingDataCollector.cs
@@ -84,6 +84,15 @@ public void AddScalar(double value)
             DataCollector.ThreadInstance.AddScalar(&value, sizeof(double));
         }
 
+        /// <summary>
+        /// Adds a Boolean value to the event payload.
+        /// </summary>
+        /// <param name="value">Value to be added.</param>
+        public void AddScalar(bool value)
+        {
+            DataCollector.ThreadInstance.AddScalar(&value, sizeof(bool));
+        }
+
         /// <summary>
         /// Adds a null-terminated String value to the event payload.
         /// </summary>