Annotate System.Net.Http for nullable

src/libraries/Common/src/Interop/OSX/Interop.CoreFoundation.CFProxy.cs

@@ -50,12 +50,12 @@ internal class CFProxy
         {
             private SafeCFDictionaryHandle _dictionary;
 
-            internal static readonly string kCFProxyTypeAutoConfigurationURL;
-            internal static readonly string kCFProxyTypeAutoConfigurationJavaScript;
-            internal static readonly string kCFProxyTypeFTP;
-            internal static readonly string kCFProxyTypeHTTP;
-            internal static readonly string kCFProxyTypeHTTPS;
-            internal static readonly string kCFProxyTypeSOCKS;
+            internal static readonly string? kCFProxyTypeAutoConfigurationURL;
+            internal static readonly string? kCFProxyTypeAutoConfigurationJavaScript;
+            internal static readonly string? kCFProxyTypeFTP;
+            internal static readonly string? kCFProxyTypeHTTP;
+            internal static readonly string? kCFProxyTypeHTTPS;
+            internal static readonly string? kCFProxyTypeSOCKS;
 
             private static readonly IntPtr kCFProxyAutoConfigurationJavaScriptKey;
             private static readonly IntPtr kCFProxyAutoConfigurationURLKey;
@@ -109,7 +109,7 @@ private static string LoadCFStringSymbol(IntPtr lib, string name)
                 }
             }
 
-            private string GetString(IntPtr key)
+            private string? GetString(IntPtr key)
             {
                 IntPtr dictValue = CFDictionaryGetValue(_dictionary, key);
                 if (dictValue != IntPtr.Zero)
@@ -122,10 +122,10 @@ private string GetString(IntPtr key)
                 return null;
             }
 
-            public string ProxyType => GetString(kCFProxyTypeKey);
-            public string HostName => GetString(kCFProxyHostNameKey);
-            public string Username => GetString(kCFProxyUsernameKey);
-            public string Password => GetString(kCFProxyPasswordKey);
+            public string? ProxyType => GetString(kCFProxyTypeKey);
+            public string? HostName => GetString(kCFProxyHostNameKey);
+            public string? Username => GetString(kCFProxyUsernameKey);
+            public string? Password => GetString(kCFProxyPasswordKey);
 
             public int PortNumber
             {

src/libraries/Common/src/Interop/Windows/WinHttp/Interop.SafeWinHttpHandle.cs

@@ -2,6 +2,7 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
+#nullable enable
 using System;
 using System.Diagnostics;
 using System.Runtime.InteropServices;
@@ -14,13 +15,13 @@ internal partial class WinHttp
     {
         internal class SafeWinHttpHandle : SafeHandleZeroOrMinusOneIsInvalid
         {
-            private SafeWinHttpHandle _parentHandle = null;
+            private SafeWinHttpHandle? _parentHandle = null;
 
             public SafeWinHttpHandle() : base(true)
             {
             }
 
-            public static void DisposeAndClearHandle(ref SafeWinHttpHandle safeHandle)
+            public static void DisposeAndClearHandle(ref SafeWinHttpHandle? safeHandle)
             {
                 if (safeHandle != null)
                 {

src/libraries/Common/src/Interop/Windows/WinHttp/Interop.winhttp.cs

@@ -2,6 +2,7 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
+#nullable enable
 using System;
 using System.Runtime.InteropServices;
 using System.Text;
@@ -189,7 +190,7 @@ public static extern bool WinHttpGetIEProxyConfigForCurrentUser(
         [DllImport(Interop.Libraries.WinHttp, CharSet = CharSet.Unicode, SetLastError = true)]
         [return: MarshalAs(UnmanagedType.Bool)]
         public static extern bool WinHttpGetProxyForUrl(
-            SafeWinHttpHandle sessionHandle, string url,
+            SafeWinHttpHandle? sessionHandle, string url,
             ref WINHTTP_AUTOPROXY_OPTIONS autoProxyOptions,
             out WINHTTP_PROXY_INFO proxyInfo);
 

src/libraries/Common/src/Interop/Windows/WinHttp/Interop.winhttp_types.cs

@@ -2,6 +2,7 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
+#nullable enable
 using System;
 using System.Runtime.InteropServices;
 using System.Text;
@@ -239,7 +240,7 @@ public struct WINHTTP_AUTOPROXY_OPTIONS
             public uint Flags;
             public uint AutoDetectFlags;
             [MarshalAs(UnmanagedType.LPWStr)]
-            public string AutoConfigUrl;
+            public string? AutoConfigUrl;
             public IntPtr Reserved1;
             public uint Reserved2;
             [MarshalAs(UnmanagedType.Bool)]

src/libraries/Common/src/System/IO/DelegatingStream.cs

@@ -2,6 +2,7 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
+#nullable enable
 using System.Diagnostics;
 using System.IO;
 using System.Threading;
@@ -113,7 +114,7 @@ public override ValueTask<int> ReadAsync(Memory<byte> buffer, CancellationToken
             return _innerStream.ReadAsync(buffer, cancellationToken);
         }
 
-        public override IAsyncResult BeginRead(byte[] buffer, int offset, int count, AsyncCallback callback, object state)
+        public override IAsyncResult BeginRead(byte[] buffer, int offset, int count, AsyncCallback? callback, object? state)
         {
             return _innerStream.BeginRead(buffer, offset, count, callback, state);
         }
@@ -167,7 +168,7 @@ public override ValueTask WriteAsync(ReadOnlyMemory<byte> buffer, CancellationTo
             return _innerStream.WriteAsync(buffer, cancellationToken);
         }
 
-        public override IAsyncResult BeginWrite(byte[] buffer, int offset, int count, AsyncCallback callback, object state)
+        public override IAsyncResult BeginWrite(byte[] buffer, int offset, int count, AsyncCallback? callback, object? state)
         {
             return _innerStream.BeginWrite(buffer, offset, count, callback, state);
         }

src/libraries/Common/src/System/IO/ReadOnlyMemoryStream.cs

@@ -105,7 +105,7 @@ public override Task<int> ReadAsync(byte[] buffer, int offset, int count, Cancel
                 new ValueTask<int>(Task.FromCanceled<int>(cancellationToken)) :
                 new ValueTask<int>(Read(buffer.Span));
 
-        public override IAsyncResult BeginRead(byte[] buffer, int offset, int count, AsyncCallback callback, object state) =>
+        public override IAsyncResult BeginRead(byte[] buffer, int offset, int count, AsyncCallback? callback, object? state) =>
             TaskToApm.Begin(ReadAsync(buffer, offset, count), callback, state);
 
         public override int EndRead(IAsyncResult asyncResult) =>

src/libraries/Common/src/System/Net/Http/NoWriteNoSeekStreamContent.cs

@@ -2,6 +2,7 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
+#nullable enable
 using System.Diagnostics;
 using System.IO;
 using System.Threading;
@@ -26,15 +27,15 @@ internal NoWriteNoSeekStreamContent(Stream content)
             _content = content;
         }
 
-        protected override Task SerializeToStreamAsync(Stream stream, TransportContext context) =>
+        protected override Task SerializeToStreamAsync(Stream stream, TransportContext? context) =>
             SerializeToStreamAsync(stream, context, CancellationToken.None);
 
 #if NETCOREAPP
         protected override
 #else
         internal
 #endif
-            Task SerializeToStreamAsync(Stream stream, TransportContext context, CancellationToken cancellationToken)
+            Task SerializeToStreamAsync(Stream stream, TransportContext? context, CancellationToken cancellationToken)
         {
             Debug.Assert(stream != null);
 
@@ -54,7 +55,7 @@ Task SerializeToStreamAsync(Stream stream, TransportContext context, Cancellatio
             {
                 copyTask = copyTask.ContinueWith((t, s) =>
                 {
-                    try { ((Stream)s).Dispose(); } catch { }
+                    try { ((Stream)s!).Dispose(); } catch { }
                     t.GetAwaiter().GetResult();
                 }, _content, CancellationToken.None, TaskContinuationOptions.ExecuteSynchronously, TaskScheduler.Default);
             }

src/libraries/Common/src/System/Net/Http/WinInetProxyHelper.cs

@@ -2,6 +2,7 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
+#nullable enable
 using System;
 using System.Runtime.InteropServices;
 
@@ -14,7 +15,7 @@ namespace System.Net.Http
     internal class WinInetProxyHelper
     {
         private const int RecentAutoDetectionInterval = 120_000; // 2 minutes in milliseconds.
-        private readonly string _autoConfigUrl, _proxy, _proxyBypass;
+        private readonly string? _autoConfigUrl, _proxy, _proxyBypass;
         private readonly bool _autoDetect;
         private readonly bool _useProxy = false;
         private bool _autoDetectionFailed;
@@ -28,10 +29,10 @@ public WinInetProxyHelper()
             {
                 if (Interop.WinHttp.WinHttpGetIEProxyConfigForCurrentUser(out proxyConfig))
                 {
-                    _autoConfigUrl = Marshal.PtrToStringUni(proxyConfig.AutoConfigUrl);
+                    _autoConfigUrl = Marshal.PtrToStringUni(proxyConfig.AutoConfigUrl)!;
                     _autoDetect = proxyConfig.AutoDetect;
-                    _proxy = Marshal.PtrToStringUni(proxyConfig.Proxy);
-                    _proxyBypass = Marshal.PtrToStringUni(proxyConfig.ProxyBypass);
+                    _proxy = Marshal.PtrToStringUni(proxyConfig.Proxy)!;
+                    _proxyBypass = Marshal.PtrToStringUni(proxyConfig.ProxyBypass)!;
 
                     if (NetEventSource.IsEnabled)
                     {
@@ -59,7 +60,7 @@ public WinInetProxyHelper()
             }
         }
 
-        public string AutoConfigUrl => _autoConfigUrl;
+        public string? AutoConfigUrl => _autoConfigUrl;
 
         public bool AutoDetect => _autoDetect;
 
@@ -69,16 +70,16 @@ public WinInetProxyHelper()
 
         public bool ManualSettingsOnly => !AutoSettingsUsed && ManualSettingsUsed;
 
-        public string Proxy => _proxy;
+        public string? Proxy => _proxy;
 
-        public string ProxyBypass => _proxyBypass;
+        public string? ProxyBypass => _proxyBypass;
 
         public bool RecentAutoDetectionFailure =>
             _autoDetectionFailed &&
             Environment.TickCount - _lastTimeAutoDetectionFailed <= RecentAutoDetectionInterval;
 
         public bool GetProxyForUrl(
-            SafeWinHttpHandle sessionHandle,
+            SafeWinHttpHandle? sessionHandle,
             Uri uri,
             out Interop.WinHttp.WINHTTP_PROXY_INFO proxyInfo)
         {
@@ -123,7 +124,7 @@ public bool GetProxyForUrl(
             {
                 _autoDetectionFailed = false;
                 if (Interop.WinHttp.WinHttpGetProxyForUrl(
-                    sessionHandle,
+                    sessionHandle!,
                     uri.AbsoluteUri,
                     ref autoProxyOptions,
                     out proxyInfo))

src/libraries/Common/src/System/Net/Http/aspnetcore/Http2/Hpack/HPackDecoder.cs

@@ -2,6 +2,7 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
+#nullable enable
 using System.Buffers;
 using System.Diagnostics;
 #if KESTREL
@@ -93,7 +94,7 @@ private enum State : byte
         private byte[] _headerValueOctets;
 
         private State _state = State.Ready;
-        private byte[] _headerName;
+        private byte[]? _headerName;
         private int _stringIndex;
         private int _stringLength;
         private int _headerNameLength;
@@ -129,13 +130,13 @@ public void Decode(in ReadOnlySequence<byte> data, bool endHeaders, IHttpHeaders
             CheckIncompleteHeaderBlock(endHeaders);
         }
 
-        public void Decode(ReadOnlySpan<byte> data, bool endHeaders, IHttpHeadersHandler handler)
+        public void Decode(ReadOnlySpan<byte> data, bool endHeaders, IHttpHeadersHandler? handler)
         {
             DecodeInternal(data, endHeaders, handler);
             CheckIncompleteHeaderBlock(endHeaders);
         }
 
-        private void DecodeInternal(ReadOnlySpan<byte> data, bool endHeaders, IHttpHeadersHandler handler)
+        private void DecodeInternal(ReadOnlySpan<byte> data, bool endHeaders, IHttpHeadersHandler? handler)
         {
             int intResult;
 
@@ -370,7 +371,7 @@ private void CheckIncompleteHeaderBlock(bool endHeaders)
             }
         }
 
-        private void ProcessHeaderValue(IHttpHeadersHandler handler)
+        private void ProcessHeaderValue(IHttpHeadersHandler? handler)
         {
             OnString(nextState: State.Ready);
 
@@ -394,7 +395,7 @@ public void CompleteDecode()
             }
         }
 
-        private void OnIndexedHeaderField(int index, IHttpHeadersHandler handler)
+        private void OnIndexedHeaderField(int index, IHttpHeadersHandler? handler)
         {
             HeaderField header = GetHeader(index);
             handler?.OnHeader(header.Name, header.Value);

src/libraries/Common/src/System/Net/Http/aspnetcore/Http2/Hpack/HPackEncoder.cs

@@ -2,6 +2,8 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
+#nullable enable
+using System.Collections.Generic;
 using System.Diagnostics;
 
 namespace System.Net.Http.HPack
@@ -370,7 +372,7 @@ public static bool EncodeStringLiteral(string value, Span<byte> destination, out
             return false;
         }
 
-        public static bool EncodeStringLiterals(ReadOnlySpan<string> values, string separator, Span<byte> destination, out int bytesWritten)
+        public static bool EncodeStringLiterals(ReadOnlySpan<string> values, string? separator, Span<byte> destination, out int bytesWritten)
         {
             bytesWritten = 0;
 
@@ -393,6 +395,7 @@ public static bool EncodeStringLiterals(ReadOnlySpan<string> values, string sepa
                     valueLength = checked((int)(valueLength + part.Length));
                 }
 
+                Debug.Assert(separator != null);
                 valueLength = checked((int)(valueLength + (values.Length - 1) * separator.Length));
 
                 destination[0] = 0;

src/libraries/Common/src/System/Net/Http/aspnetcore/Http3/QPack/QPackDecoder.cs

@@ -2,6 +2,7 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
+#nullable enable
 using System.Buffers;
 using System.Diagnostics;
 using System.Net.Http.HPack;
@@ -118,7 +119,7 @@ private enum State
         private bool _huffman;
         private int? _index;
 
-        private byte[] _headerName;
+        private byte[]? _headerName;
         private int _headerNameLength;
         private int _headerValueLength;
         private int _stringLength;
@@ -130,7 +131,7 @@ private enum State
         private static void ReturnAndGetNewPooledArray(ref byte[] buffer, int newSize)
         {
             byte[] old = buffer;
-            buffer = null;
+            buffer = null!;
 
             Pool.Return(old, clearArray: true);
             buffer = Pool.Rent(newSize);
@@ -151,19 +152,19 @@ public void Dispose()
             if (_stringOctets != null)
             {
                 Pool.Return(_stringOctets, true);
-                _stringOctets = null;
+                _stringOctets = null!;
             }
 
             if (_headerNameOctets != null)
             {
                 Pool.Return(_headerNameOctets, true);
-                _headerNameOctets = null;
+                _headerNameOctets = null!;
             }
 
             if (_headerValueOctets != null)
             {
                 Pool.Return(_headerValueOctets, true);
-                _headerValueOctets = null;
+                _headerValueOctets = null!;
             }
         }