[2019-12] Make MonoWebRequestHandler linker friendly (#18833)mono-6.10.0.76

* Make MonoWebRequestHandler linker friendly

* Make MonoWebRequestHandler's ctor public (to be able to use in Activator.CreateInstance without binding flags)

* Remove Console.WriteLine from system.net.http

Co-authored-by: Egor Bogatov <egorbo@gmail.com>

3 files changed, 20 insertions, 15 deletions

diff --git a/mcs/class/System.Net.Http/HttpClientHandler.SocketsHandler.Android.cs b/mcs/class/System.Net.Http/HttpClientHandler.SocketsHandler.Android.cs
index c483c28f03b..9b4fadc19f1 100644
--- a/mcs/class/System.Net.Http/HttpClientHandler.SocketsHandler.Android.cs
+++ b/mcs/class/System.Net.Http/HttpClientHandler.SocketsHandler.Android.cs
@@ -1,3 +1,5 @@
+using System.Reflection;
+
 namespace System.Net.Http
 {
 	partial class HttpClientHandler : HttpMessageHandler
@@ -6,7 +8,12 @@ namespace System.Net.Http
 		{
 			string envvar = Environment.GetEnvironmentVariable ("XA_HTTP_CLIENT_HANDLER_TYPE")?.Trim ();
 			if (envvar?.StartsWith("System.Net.Http.MonoWebRequestHandler", StringComparison.InvariantCulture) == true)
-				return new MonoWebRequestHandler ();
+			{
+				Type monoWrhType = Type.GetType (envvar, false);
+				if (monoWrhType != null)
+					return (IMonoHttpClientHandler) Activator.CreateInstance (monoWrhType);
+			}
+
 			// Ignore other types of handlers here (e.g. AndroidHttpHandler) to keep the old behavior
 			// and always create SocketsHttpHandler for code like this if MonoWebRequestHandler was not specified:
 			//
diff --git a/mcs/class/System.Net.Http/MonoWebRequestHandler.cs b/mcs/class/System.Net.Http/MonoWebRequestHandler.cs
index 023343f01f4..27c904adfdf 100644
--- a/mcs/class/System.Net.Http/MonoWebRequestHandler.cs
+++ b/mcs/class/System.Net.Http/MonoWebRequestHandler.cs
@@ -70,7 +70,7 @@ namespace System.Net.Http
 		TimeSpan? timeout;
 		bool disposed;
 
-		internal MonoWebRequestHandler ()
+		public MonoWebRequestHandler ()
 		{
 			allowAutoRedirect = true;
 			maxAutomaticRedirections = 50;
diff --git a/mcs/class/System.Net.Http/System.Net.Http/HttpClient.android.cs b/mcs/class/System.Net.Http/System.Net.Http/HttpClient.android.cs
index 9b899bcffd8..8ea04ac4880 100644
--- a/mcs/class/System.Net.Http/System.Net.Http/HttpClient.android.cs
+++ b/mcs/class/System.Net.Http/System.Net.Http/HttpClient.android.cs
@@ -11,10 +11,16 @@ namespace System.Net.Http {
 			string envvar = Environment.GetEnvironmentVariable ("XA_HTTP_CLIENT_HANDLER_TYPE")?.Trim ();
 
 			if (string.IsNullOrEmpty (envvar))
-				return GetFallback ($"XA_HTTP_CLIENT_HANDLER_TYPE is empty");
+				return new HttpClientHandler ();
 
-			if (envvar?.StartsWith("System.Net.Http.MonoWebRequestHandler", StringComparison.InvariantCulture) == true)
-				return new HttpClientHandler (new MonoWebRequestHandler ());
+			if (envvar?.StartsWith ("System.Net.Http.MonoWebRequestHandler", StringComparison.InvariantCulture) == true)
+			{
+				Type monoWrhType = Type.GetType (envvar, false);
+				if (monoWrhType != null)
+					return new HttpClientHandler ((IMonoHttpClientHandler) Activator.CreateInstance (monoWrhType));
+
+				return new HttpClientHandler ();
+			}
 
 			Type handlerType = Type.GetType (envvar, false);
 			if (handlerType == null && !envvar.Contains (", "))
@@ -25,19 +31,11 @@ namespace System.Net.Http {
 			}
 
 			if (handlerType == null)
-				return GetFallback ($"'{envvar}' type was not found");
-
-			object handlerObj = Activator.CreateInstance (handlerType);
+				return new HttpClientHandler ();
 
-			if (handlerObj is HttpMessageHandler msgHandler)
+			if (Activator.CreateInstance (handlerType) is HttpMessageHandler msgHandler)
 				return msgHandler;
 
-			return GetFallback ($"{handlerObj?.GetType ()} is not a valid HttpMessageHandler or MonoWebRequestHandler");
-		}
-
-		static HttpMessageHandler GetFallback (string message)
-		{
-			Console.WriteLine (message + ". Defaulting to System.Net.Http.HttpClientHandler");
 			return new HttpClientHandler ();
 		}
 	}