[corlib] BinaryReader with Unicode encoding needs to read bytes in a pair. Fixes #30171mono-4.0.1.44

2 files changed, 21 insertions, 0 deletions

diff --git a/mcs/class/corlib/System.IO/BinaryReader.cs b/mcs/class/corlib/System.IO/BinaryReader.cs
index 73235c9c23d..bbcd8174e71 100644
--- a/mcs/class/corlib/System.IO/BinaryReader.cs
+++ b/mcs/class/corlib/System.IO/BinaryReader.cs
@@ -253,6 +253,13 @@ namespace System.IO {
 
 					m_buffer [pos ++] = (byte)read_byte;
 					bytes_read ++;
+					if (m_encoding is UnicodeEncoding) {
+						CheckBuffer (pos + 1);
+						read_byte = m_stream.ReadByte();
+						if (read_byte != -1) {
+							m_buffer [pos++] = (byte)read_byte;
+						}
+					}
 
 					int n = m_encoding.GetChars (m_buffer, 0, pos, buffer, index + chars_read);
 					if (n > 0)
diff --git a/mcs/class/corlib/Test/System.IO/BinaryReaderTest.cs b/mcs/class/corlib/Test/System.IO/BinaryReaderTest.cs
index 852d69089b3..ca4e3daafdd 100644
--- a/mcs/class/corlib/Test/System.IO/BinaryReaderTest.cs
+++ b/mcs/class/corlib/Test/System.IO/BinaryReaderTest.cs
@@ -274,6 +274,20 @@ namespace MonoTests.System.IO
 			}
 		}
 
+		[Test]
+		public void TestReadUnicode ()
+		{
+			char testChar1 = 'H';
+			using (var stream = new MemoryStream())
+			using (var writer = new BinaryWriter(stream, Encoding.Unicode, true))
+			using (var reader = new BinaryReader(stream, Encoding.Unicode))
+			{
+				writer.Write(testChar1);
+				stream.Position = 0;
+				Assert.AreEqual ('H', reader.ReadChar ());
+			}
+		}
+
 
 		//-TODO: (TestRead[Type]*) Verify the ReadBoolean, ReadByte ....
 		// ReadBoolean, ReadByte, ReadChar, ReadInt32 Done