From a1a9f49ee8eabd8799cdb3b6f4e8b019c247aa40 Mon Sep 17 00:00:00 2001
From: Matt Mitchell <mmitche@microsoft.com>
Date: Tue, 27 Jul 2021 07:57:07 -0700
Subject: [PATCH] Revert "Split mobile specific ILLink.Substitutions into its
 own file (#56306)"

This reverts commit ae413d9a81ede4cd7c624d7ec7792c16ad8b8f21.
---
 .../src/ILLink/ILLink.Substitutions.mobile.xml         |  7 -------
 .../src/ILLink/ILLink.Substitutions.xml                |  3 +++
 .../System.Net.Http/src/System.Net.Http.csproj         |  4 +---
 .../System.Net.Http/src/System/Net/Http/HttpClient.cs  | 10 ++++++++++
 4 files changed, 14 insertions(+), 10 deletions(-)
 delete mode 100644 src/libraries/System.Net.Http/src/ILLink/ILLink.Substitutions.mobile.xml

diff --git a/src/libraries/System.Net.Http/src/ILLink/ILLink.Substitutions.mobile.xml b/src/libraries/System.Net.Http/src/ILLink/ILLink.Substitutions.mobile.xml
deleted file mode 100644
index 5b705abeb24bd..0000000000000
--- a/src/libraries/System.Net.Http/src/ILLink/ILLink.Substitutions.mobile.xml
+++ /dev/null
@@ -1,7 +0,0 @@
-<linker>
-  <assembly fullname="System.Net.Http">
-    <type fullname="System.Net.Http.HttpClientHandler">
-      <method signature="System.Boolean get_IsNativeHandlerEnabled()" body="stub" value="false" feature="System.Net.Http.UseNativeHttpHandler" featurevalue="false" />
-    </type>
-  </assembly>
-</linker>
diff --git a/src/libraries/System.Net.Http/src/ILLink/ILLink.Substitutions.xml b/src/libraries/System.Net.Http/src/ILLink/ILLink.Substitutions.xml
index 5e70f6fbb5d7d..8af1dcbdfa8a6 100644
--- a/src/libraries/System.Net.Http/src/ILLink/ILLink.Substitutions.xml
+++ b/src/libraries/System.Net.Http/src/ILLink/ILLink.Substitutions.xml
@@ -3,5 +3,8 @@
     <type fullname="System.Net.Http.DiagnosticsHandler">
       <method signature="System.Boolean IsGloballyEnabled()" body="stub" value="false" feature="System.Net.Http.EnableActivityPropagation" featurevalue="false" />
     </type>
+    <type fullname="System.Net.Http.HttpClientHandler">
+      <method signature="System.Boolean get_IsNativeHandlerEnabled()" body="stub" value="false" feature="System.Net.Http.UseNativeHttpHandler" featurevalue="false" />
+    </type>
   </assembly>
 </linker>
diff --git a/src/libraries/System.Net.Http/src/System.Net.Http.csproj b/src/libraries/System.Net.Http/src/System.Net.Http.csproj
index 77ed5b9c436c6..330c6cf161446 100644
--- a/src/libraries/System.Net.Http/src/System.Net.Http.csproj
+++ b/src/libraries/System.Net.Http/src/System.Net.Http.csproj
@@ -1,4 +1,4 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <WindowsRID>win</WindowsRID>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
@@ -18,8 +18,6 @@
   </PropertyGroup>
   <ItemGroup>
     <ILLinkSubstitutionsXmls Include="$(ILLinkDirectory)ILLink.Substitutions.xml" />
-    <ILLinkSubstitutionsXmls Condition="'$(TargetsAndroid)' == 'true' or '$(TargetsiOS)' == 'true' or '$(TargetsMacCatalyst)' == 'true' or '$(TargetsTVOS)' == 'true'"
-                             Include="$(ILLinkDirectory)ILLink.Substitutions.mobile.xml" />
   </ItemGroup>
   <ItemGroup>
     <Compile Include="System\Net\Http\ByteArrayContent.cs" />
diff --git a/src/libraries/System.Net.Http/src/System/Net/Http/HttpClient.cs b/src/libraries/System.Net.Http/src/System/Net/Http/HttpClient.cs
index 3b77aeafc0467..2e1434b0b4993 100644
--- a/src/libraries/System.Net.Http/src/System/Net/Http/HttpClient.cs
+++ b/src/libraries/System.Net.Http/src/System/Net/Http/HttpClient.cs
@@ -815,6 +815,16 @@ private void PrepareRequestMessage(HttpRequestMessage request)
             return (pendingRequestsCts, DisposeTokenSource: false, pendingRequestsCts);
         }
 
+        private static bool IsNativeHandlerEnabled()
+        {
+            if (!AppContext.TryGetSwitch("System.Net.Http.UseNativeHttpHandler", out bool isEnabled))
+            {
+                return false;
+            }
+
+            return isEnabled;
+        }
+
         private Uri? CreateUri(string? uri) =>
             string.IsNullOrEmpty(uri) ? null : new Uri(uri, UriKind.RelativeOrAbsolute);