[System.IO.Compression] Fixed DeflateStream inflate() decompression loop.

This reworks the fix from https://github.com/mono/mono/commit/7c4d41a518aaf0370b882f9430752ebcd5544c10.

That fix introduced a regression when handling some inputs, which lead us to ignore
some left-over data from zlib's inflate output buffer.

Now we only break from the loop if inflate() returns Z_BUF_ERROR.

This makes sure all data is fully processed before returning to managed code.

Fixes one of the bugs in https://bugzilla.xamarin.com/show_bug.cgi?id=44994#c2.

1 files changed, 21 insertions, 0 deletions

diff --git a/mcs/class/System/Test/System.IO.Compression/DeflateStreamTest.cs b/mcs/class/System/Test/System.IO.Compression/DeflateStreamTest.cs
index 0fe01aaf102..4fef4c5f4d8 100644
--- a/mcs/class/System/Test/System.IO.Compression/DeflateStreamTest.cs
+++ b/mcs/class/System/Test/System.IO.Compression/DeflateStreamTest.cs
@@ -410,6 +410,27 @@ namespace MonoTests.System.IO.Compression
 			using (var unZippedStream = new StreamReader (gZipStream, Encoding.UTF8)) {
 				unZipped = unZippedStream.ReadToEnd ();
 			}
+
+			Assert.AreEqual(1877, unZipped.Length);
+		}
+
+		[Test]
+		public void Bug44994_Inflate()
+		{
+			var base64String = @"7cWxCQAgDACwpeBjgqsgXiHU0fd9QzBLErX1EQAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAADepcxcuU/atm3btm3btm3btm3btm3btm3btm3btm3btm3btm3btm3btm3btm3btm3btm3btm3btm3btm3btm3btm3btm3btm3btm3btm3btm3btm3btm3btm3btm3btm37zy8=";
+
+			byte[] byteArray = Convert.FromBase64String(base64String);
+			string unZipped = null;
+
+			using (var zippedMemoryStream = new MemoryStream(byteArray))
+			using (var gZipStream = new DeflateStream(zippedMemoryStream, CompressionMode.Decompress))
+			using (var unzippedMemStream = new MemoryStream())
+			using (var unZippedStream = new StreamReader(gZipStream, Encoding.UTF8))
+			{
+				unZipped = unZippedStream.ReadToEnd();
+			}
+
+			Assert.AreEqual(81942, unZipped.Length);
 		}
 	}
 }