Merge PR #387: Better handle baseStreams closing themselves unexpectedly

* Unit test for issue #379
* Change InflaterInputBuffer.Fill() to stop trying to read from inputStream in its CanRead property is false.

Author: Numpsy

src/ICSharpCode.SharpZipLib/Zip/Compression/Streams/InflaterInputStream.cs

@@ -116,7 +116,7 @@ public void Fill()
 			rawLength = 0;
 			int toRead = rawData.Length;
 
-			while (toRead > 0)
+			while (toRead > 0 && inputStream.CanRead)
 			{
 				int count = inputStream.Read(rawData, rawLength, toRead);
 				if (count <= 0)

test/ICSharpCode.SharpZipLib.Tests/GZip/GZipTests.cs

@@ -390,9 +390,41 @@ public void SmallBufferDecompression()
 
 
 				}
+			}
+
 		}
 
-	}
+		/// <summary>
+		/// Should gracefully handle reading from a stream that becomes unreadable after
+		///  all of the data has been read.
+		/// </summary>
+		/// <remarks>
+		/// Test for https://github.com/icsharpcode/SharpZipLib/issues/379
+		/// </remarks>
+		[Test]
+		[Category("Zip")]
+		public void ShouldGracefullyHandleReadingANonReableStream()
+		{
+			MemoryStream ms = new SelfClosingStream();
+			using (var gzos = new GZipOutputStream(ms))
+			{
+				gzos.IsStreamOwner = false;
+
+				byte[] buf = new byte[100000];
+				var rnd = new Random();
+				rnd.NextBytes(buf);
+
+				gzos.Write(buf, 0, buf.Length);
+			}
+
+			ms.Seek(0, SeekOrigin.Begin);
+
+			using (var gzis = new GZipInputStream(ms))
+			using (var msRaw = new MemoryStream())
+			{
+				gzis.CopyTo(msRaw);
+			}
+		}
 
 		[Test]
 		[Category("GZip")]

test/ICSharpCode.SharpZipLib.Tests/TestSupport/Streams.cs

@@ -539,4 +539,52 @@ public override int Read(byte[] buffer, int offset, int count)
 			return base.Read(buffer, offset, count);
 		}
 	}
+
+	/// <summary>
+	/// A stream that closes itself when all of its data is read.
+	/// </summary>
+	/// <remarks>
+	/// Useful for testing issues such as https://github.com/icsharpcode/SharpZipLib/issues/379
+	/// </remarks>
+	internal class SelfClosingStream : MemoryStream
+	{
+		private bool isFullyRead = false;
+
+		/// <summary>
+		/// Initializes a new instance of the <see cref="SelfClosingStream"/> class.
+		/// </summary>
+		public SelfClosingStream()
+		{
+		}
+
+		// <inheritdoc/>
+		public override int Read(byte[] buffer, int offset, int count)
+		{
+			var read = base.Read(buffer, offset, count);
+
+			if (read == 0)
+			{
+				isFullyRead = true;
+				Close();
+			}
+
+			return read;
+		}
+
+		/// <summary>
+		/// CanRead is false if we're closed, or base.CanRead otherwise.
+		/// </summary>
+		public override bool CanRead
+		{
+			get
+			{
+				if (isFullyRead)
+				{
+					return false;
+				}
+
+				return base.CanRead;
+			}
+		}
+	}
 }