Add stream checks before returning it (#119243)

* Add checks to see if the stream is disposed before returning them

* Fix the test since the functions throw ObjectDisposedException now

Author: iremyux

src/libraries/Common/tests/System/IO/Compression/CompressionStreamUnitTestBase.cs

@@ -441,13 +441,13 @@ public async Task BaseStream_Modify(CompressionMode mode)
         [Theory]
         [InlineData(CompressionMode.Compress)]
         [InlineData(CompressionMode.Decompress)]
-        public void BaseStream_NullAfterDisposeWithFalseLeaveOpen(CompressionMode mode)
+        public void BaseStream_ThrowsAfterDisposeWithFalseLeaveOpen(CompressionMode mode)
         {
             var ms = new MemoryStream();
             using var compressor = CreateStream(ms, mode);
             compressor.Dispose();
 
-            Assert.Null(BaseStream(compressor));
+            Assert.Throws<ObjectDisposedException>(() => BaseStream(compressor));
 
             compressor.Dispose(); // Should be a no-op
         }

src/libraries/System.IO.Compression.Brotli/src/System/IO/Compression/BrotliStream.cs

@@ -138,7 +138,14 @@ private void ReleaseStateForDispose()
         /// <summary>Gets a reference to the underlying stream.</summary>
         /// <value>A stream object that represents the underlying stream.</value>
         /// <exception cref="System.ObjectDisposedException">The underlying stream is closed.</exception>
-        public Stream BaseStream => _stream;
+        public Stream BaseStream
+        {
+            get
+            {
+                EnsureNotDisposed();
+                return _stream;
+            }
+        }
         /// <summary>Gets a value indicating whether the stream supports reading while decompressing a file.</summary>
         /// <value><see langword="true" /> if the <see cref="System.IO.Compression.CompressionMode" /> value is <see langword="Decompress," /> and the underlying stream supports reading and is not closed; otherwise, <see langword="false" />.</value>
         public override bool CanRead => _mode == CompressionMode.Decompress && _stream != null && _stream.CanRead;

src/libraries/System.IO.Compression/src/System/IO/Compression/DeflateZLib/DeflateStream.cs

@@ -153,7 +153,14 @@ private void EnsureBufferInitialized()
             }
         }
 
-        public Stream BaseStream => _stream;
+        public Stream BaseStream
+        {
+            get
+            {
+                EnsureNotDisposed();
+                return _stream;
+            }
+        }
 
         public override bool CanRead
         {

src/libraries/System.IO.Compression/src/System/IO/Compression/GZipStream.cs

@@ -194,7 +194,14 @@ public override ValueTask DisposeAsync()
             return default;
         }
 
-        public Stream BaseStream => _deflateStream?.BaseStream!;
+        public Stream BaseStream
+        {
+            get
+            {
+                CheckDeflateStream();
+                return _deflateStream.BaseStream;
+            }
+        }
 
         public override Task<int> ReadAsync(byte[] buffer, int offset, int count, CancellationToken cancellationToken)
         {

src/libraries/System.IO.Compression/src/System/IO/Compression/ZLibStream.cs

@@ -286,7 +286,14 @@ public override ValueTask DisposeAsync()
         }
 
         /// <summary>Gets a reference to the underlying stream.</summary>
-        public Stream BaseStream => _deflateStream?.BaseStream!;
+        public Stream BaseStream
+        {
+            get
+            {
+                ThrowIfClosed();
+                return _deflateStream.BaseStream;
+            }
+        }
 
         /// <summary>Throws an <see cref="ObjectDisposedException"/> if the stream is closed.</summary>
         private void ThrowIfClosed()