Support ISerializable in ReflectionOnly mode. (dotnet/corefx#14551)

* Support ISerializable in ReflectionOnly mode.

Fix dotnet/corefx#13071

* Address feedback.


Commit migrated from https://github.com/dotnet/corefx/commit/c573a141bbbd5d7027855890354668db99ae870c

src/libraries/System.Private.DataContractSerialization/src/System/Runtime/Serialization/ReflectionClassWriter.cs

@@ -21,7 +21,15 @@ public void ReflectionWriteClass(XmlWriterDelegator xmlWriter, object obj, XmlOb
         {
             InvokeOnSerializing(obj, context, classContract);
             obj = ResolveAdapterType(obj, classContract);
-            ReflectionWriteMembers(xmlWriter, obj, context, classContract, classContract, 0 /*childElementIndex*/, memberNames);
+            if (classContract.IsISerializable)
+            {
+                context.WriteISerializable(xmlWriter, (ISerializable) obj);
+            }
+            else
+            {
+                ReflectionWriteMembers(xmlWriter, obj, context, classContract, classContract, 0 /*childElementIndex*/, memberNames);
+            }
+
             InvokeOnSerialized(obj, context, classContract);
         }
 

src/libraries/System.Private.DataContractSerialization/src/System/Runtime/Serialization/ReflectionReader.cs

@@ -33,7 +33,15 @@ public object ReflectionReadClass(XmlReaderDelegator xmlReader, XmlObjectSeriali
             context.AddNewObject(obj);
             InvokeOnDeserializing(context, classContract, obj);
 
-            ReflectionReadMembers(xmlReader, context, memberNames, memberNamespaces, classContract, ref obj);
+            if (classContract.IsISerializable)
+            {
+                obj = ReadISerializable(xmlReader, context, classContract);
+            }
+            else
+            {
+                ReflectionReadMembers(xmlReader, context, memberNames, memberNamespaces, classContract, ref obj);
+            }
+
             obj = ResolveAdapterObject(obj, classContract);
             InvokeDeserializationCallback(obj);
             InvokeOnDeserialized(context, classContract, obj);
@@ -279,6 +287,16 @@ private object ReadItemOfPrimitiveType(XmlReaderDelegator xmlReader, XmlObjectSe
             return value;
         }
 
+        private static object ReadISerializable(XmlReaderDelegator xmlReader, XmlObjectSerializerReadContext context, ClassDataContract classContract)
+        {
+            object obj;
+            SerializationInfo serializationInfo = context.ReadSerializationInfo(xmlReader, classContract.UnderlyingType);
+            StreamingContext streamingContext = context.GetStreamingContext();
+            ConstructorInfo iSerializableConstructor = classContract.GetISerializableConstructor();
+            obj = iSerializableConstructor.Invoke(new object[] { serializationInfo, streamingContext });
+            return obj;
+        }
+
         // This method is a perf optimization for collections. The original method is ReflectionReadValue.
         private CollectionReadItemDelegate GetReflectionReadValueDelegate(Type type)
         {

src/libraries/System.Runtime.Serialization.Json/tests/DataContractJsonSerializer.cs

@@ -2240,9 +2240,6 @@ public static void DCJS_CreateJsonWriterTest()
         }
     }
 
-#if ReflectionOnly
-    [ActiveIssue(13071)]
-#endif
     [Fact]
     public static void DCJS_MyISerializableType()
     {

src/libraries/System.Runtime.Serialization.Xml/tests/DataContractSerializer.cs

@@ -1431,9 +1431,6 @@ public static void DCS_RootNameNamespaceAndKnownTypesThroughConstructorAsXmlDict
         Assert.StrictEqual(((SimpleKnownTypeValue)actual.SimpleTypeValue).StrProperty, "PropertyValue");
     }
 
-#if ReflectionOnly
-    [ActiveIssue(13071)]
-#endif
     [Fact]
     public static void DCS_ExceptionObject()
     {
@@ -1448,9 +1445,6 @@ public static void DCS_ExceptionObject()
         Assert.StrictEqual(value.HelpLink, actual.HelpLink);
     }
 
-#if ReflectionOnly
-    [ActiveIssue(13071)]
-#endif
     [Fact]
     public static void DCS_ArgumentExceptionObject()
     {
@@ -1465,9 +1459,6 @@ public static void DCS_ArgumentExceptionObject()
         Assert.StrictEqual(value.HelpLink, actual.HelpLink);
     }
 
-#if ReflectionOnly
-    [ActiveIssue(13071)]
-#endif
     [Fact]
     public static void DCS_ExceptionMesageWithSpecialChars()
     {
@@ -1482,9 +1473,6 @@ public static void DCS_ExceptionMesageWithSpecialChars()
         Assert.StrictEqual(value.HelpLink, actual.HelpLink);
     }
 
-#if ReflectionOnly
-    [ActiveIssue(13071)]
-#endif
     [Fact]
     public static void DCS_InnerExceptionMesageWithSpecialChars()
     {
@@ -2756,9 +2744,6 @@ public static void XsdDataContractExporterTest()
         Assert.Throws<PlatformNotSupportedException>(() => exporter.Export(typeof(Employee)));
     }
 
-#if ReflectionOnly
-    [ActiveIssue(13071)]
-#endif
     [Fact]
     public static void DCS_MyISerializableType()
     {