Fix build break due to conflicting PRs (#23726)

3 files changed, 9 insertions, 10 deletions

diff --git a/src/System.Private.CoreLib/shared/System/IO/FileStream.Unix.cs b/src/System.Private.CoreLib/shared/System/IO/FileStream.Unix.cs
index 7e38f9b09a..62e1fdec25 100644
--- a/src/System.Private.CoreLib/shared/System/IO/FileStream.Unix.cs
+++ b/src/System.Private.CoreLib/shared/System/IO/FileStream.Unix.cs
@@ -291,7 +291,7 @@ namespace System.IO
             // override may already exist on a derived type.
             if (_useAsyncIO && _writePos > 0)
             {
-                return new ValueTask(Task.Factory.StartNew(s => ((FileStream)s).Dispose(), this,
+                return new ValueTask(Task.Factory.StartNew(s => ((FileStream)s!).Dispose(), this, // TODO-NULLABLE: https://github.com/dotnet/roslyn/issues/26761
                     CancellationToken.None, TaskCreationOptions.DenyChildAttach, TaskScheduler.Default));
             }
 
@@ -365,7 +365,7 @@ namespace System.IO
             if (CanWrite)
             {
                 return Task.Factory.StartNew(
-                    state => ((FileStream)state).FlushOSBuffer(),
+                    state => ((FileStream)state!).FlushOSBuffer(), // TODO-NULLABLE: https://github.com/dotnet/roslyn/issues/26761
                     this,
                     cancellationToken,
                     TaskCreationOptions.DenyChildAttach,
@@ -569,7 +569,7 @@ namespace System.IO
                 // whereas on Windows it may happen before the write has completed.
 
                 Debug.Assert(t.Status == TaskStatus.RanToCompletion);
-                var thisRef = (FileStream)s;
+                var thisRef = (FileStream)s!; // TODO-NULLABLE: https://github.com/dotnet/roslyn/issues/26761
                 Debug.Assert(thisRef._asyncState != null);
                 try
                 {
@@ -728,7 +728,7 @@ namespace System.IO
                 // whereas on Windows it may happen before the write has completed.
 
                 Debug.Assert(t.Status == TaskStatus.RanToCompletion);
-                var thisRef = (FileStream)s;
+                var thisRef = (FileStream)s!; // TODO-NULLABLE: https://github.com/dotnet/roslyn/issues/26761
                 Debug.Assert(thisRef._asyncState != null);
                 try
                 {
diff --git a/src/System.Private.CoreLib/shared/System/IO/FileStream.Windows.cs b/src/System.Private.CoreLib/shared/System/IO/FileStream.Windows.cs
index 6996a3b2ec..4de7a3b254 100644
--- a/src/System.Private.CoreLib/shared/System/IO/FileStream.Windows.cs
+++ b/src/System.Private.CoreLib/shared/System/IO/FileStream.Windows.cs
@@ -49,7 +49,7 @@ namespace System.IO
 
         private static readonly unsafe IOCompletionCallback s_ioCallback = FileStreamCompletionSource.IOCallback;
 
-        private Task? _activeBufferOperation = null;                 // tracks in-progress async ops using the buffer
+        private Task _activeBufferOperation = Task.CompletedTask;    // tracks in-progress async ops using the buffer
         private PreAllocatedOverlapped? _preallocatedOverlapped;     // optimization for async ops to avoid per-op allocations
         private FileStreamCompletionSource? _currentOverlappedOwner; // async op currently using the preallocated overlapped
 
@@ -197,8 +197,7 @@ namespace System.IO
             return secAttrs;
         }
 
-        private bool HasActiveBufferOperation
-            => _activeBufferOperation != null && !_activeBufferOperation.IsCompleted;
+        private bool HasActiveBufferOperation => !_activeBufferOperation.IsCompleted;
 
         public override bool CanSeek => _canSeek;
 
@@ -1589,7 +1588,7 @@ namespace System.IO
             if (CanWrite)
             {
                 return Task.Factory.StartNew(
-                    state => ((FileStream)state).FlushOSBuffer(),
+                    state => ((FileStream)state!).FlushOSBuffer(), // TODO-NULLABLE: https://github.com/dotnet/roslyn/issues/26761
                     this,
                     cancellationToken,
                     TaskCreationOptions.DenyChildAttach,
diff --git a/src/System.Private.CoreLib/shared/System/IO/Stream.cs b/src/System.Private.CoreLib/shared/System/IO/Stream.cs
index 66a0094505..1f0943f2fc 100644
--- a/src/System.Private.CoreLib/shared/System/IO/Stream.cs
+++ b/src/System.Private.CoreLib/shared/System/IO/Stream.cs
@@ -256,7 +256,7 @@ namespace System.IO
 
         public virtual Task FlushAsync(CancellationToken cancellationToken)
         {
-            return Task.Factory.StartNew(state => ((Stream)state).Flush(), this,
+            return Task.Factory.StartNew(state => ((Stream)state!).Flush(), this, // TODO-NULLABLE: https://github.com/dotnet/roslyn/issues/26761
                 cancellationToken, TaskCreationOptions.DenyChildAttach, TaskScheduler.Default);
         }
 
@@ -512,7 +512,7 @@ namespace System.IO
                 asyncWaiter.ContinueWith((t, state) =>
                 {
                     Debug.Assert(t.IsCompletedSuccessfully, "The semaphore wait should always complete successfully.");
-                    var rwt = (ReadWriteTask)state;
+                    var rwt = (ReadWriteTask)state!; // TODO-NULLABLE: https://github.com/dotnet/roslyn/issues/26761
                     Debug.Assert(rwt._stream != null);
                     rwt._stream.RunReadWriteTask(rwt); // RunReadWriteTask(readWriteTask);
                 }, readWriteTask, default, TaskContinuationOptions.ExecuteSynchronously, TaskScheduler.Default);