Replace Array.Copy with Buffer.BlockCopy.

See discussion at dotnet/corefx#6103.

Author: bgrainger

src/MySql.Data/ByteArrayReader.cs

@@ -111,7 +111,7 @@ public byte[] ReadNullTerminatedByteString()
 			if (index == m_maxOffset)
 				throw new FormatException("Read past end of buffer looking for NUL.");
 			byte[] substring = new byte[index - m_offset];
-			Array.Copy(m_buffer, m_offset, substring, 0, substring.Length);
+			Buffer.BlockCopy(m_buffer, m_offset, substring, 0, substring.Length);
 			m_offset = index + 1;
 			return substring;
 		}
@@ -120,7 +120,7 @@ public byte[] ReadByteString(int length)
 		{
 			VerifyRead(length);
 			var result = new byte[length];
-			Array.Copy(m_buffer, m_offset, result, 0, result.Length);
+			Buffer.BlockCopy(m_buffer, m_offset, result, 0, result.Length);
 			m_offset += length;
 			return result;
 		}

src/MySql.Data/MySqlClient/MySqlDataReader.cs

@@ -136,7 +136,7 @@ public override long GetBytes(int ordinal, long dataOffset, byte[] buffer, int b
 				throw new ArgumentException("bufferOffset + length cannot exceed buffer.Length", nameof(length));
 
 			int lengthToCopy = Math.Min(m_dataLengths[ordinal] - (int) dataOffset, length);
-			Array.Copy(m_currentRow, checked((int) (m_dataOffsets[ordinal] + dataOffset)), buffer, bufferOffset, lengthToCopy);
+			Buffer.BlockCopy(m_currentRow, checked((int) (m_dataOffsets[ordinal] + dataOffset)), buffer, bufferOffset, lengthToCopy);
 			return lengthToCopy;
 		}
 
@@ -399,7 +399,7 @@ public override object GetValue(int ordinal)
 				if (columnDefinition.CharacterSet == CharacterSet.Binary)
 				{
 					var result = new byte[m_dataLengths[ordinal]];
-					Array.Copy(m_currentRow, m_dataOffsets[ordinal], result, 0, result.Length);
+					Buffer.BlockCopy(m_currentRow, m_dataOffsets[ordinal], result, 0, result.Length);
 					return Connection.OldGuids && columnDefinition.ColumnLength == 16 ? (object) new Guid(result) : result;
 				}
 				return Encoding.UTF8.GetString(data);

src/MySql.Data/Serialization/AuthenticationUtility.cs

@@ -19,13 +19,13 @@ public static byte[] HashPassword(byte[] challenge, int offset, string password)
 			using (var sha1 = SHA1.Create())
 			{
 				var combined = new byte[40];
-				Array.Copy(challenge, offset, combined, 0, 20);
+				Buffer.BlockCopy(challenge, offset, combined, 0, 20);
 
 				var passwordBytes = Encoding.UTF8.GetBytes(password);
 				var hashedPassword = sha1.ComputeHash(passwordBytes);
 
 				var doubleHashedPassword = sha1.ComputeHash(hashedPassword);
-				Array.Copy(doubleHashedPassword, 0, combined, 20, 20);
+				Buffer.BlockCopy(doubleHashedPassword, 0, combined, 20, 20);
 
 				var xorBytes = sha1.ComputeHash(combined);
 				for (int i = 0; i < hashedPassword.Length; i++)

src/MySql.Data/Serialization/InitialHandshakePacket.cs

@@ -31,8 +31,8 @@ internal InitialHandshakePacket(ByteArrayReader reader)
 				{
 					var authPluginData2 = reader.ReadByteString(Math.Max(13, authPluginDataLength - 8));
 					var concatenated = new byte[AuthPluginData.Length + authPluginData2.Length];
-					Array.Copy(AuthPluginData, concatenated, AuthPluginData.Length);
-					Array.Copy(authPluginData2, 0, concatenated, AuthPluginData.Length, authPluginData2.Length);
+					Buffer.BlockCopy(AuthPluginData, 0, concatenated, 0, AuthPluginData.Length);
+					Buffer.BlockCopy(authPluginData2, 0, concatenated, AuthPluginData.Length, authPluginData2.Length);
 					AuthPluginData = concatenated;
 				}
 				if (ProtocolCapabilities.HasFlag(ProtocolCapabilities.PluginAuth))

src/MySql.Data/Serialization/PacketTransmitter.cs

@@ -63,7 +63,7 @@ private async Task DoSendAsync(PayloadData payload, CancellationToken cancellati
 
 				if (bytesToSend <= m_buffer.Length - 4)
 				{
-					Array.Copy(data.Array, data.Offset, m_buffer, 4, bytesToSend);
+					Buffer.BlockCopy(data.Array, data.Offset, m_buffer, 4, bytesToSend);
 					m_socketAwaitable.EventArgs.SetBuffer(0, bytesToSend + 4);
 					await m_socket.SendAsync(m_socketAwaitable);
 				}
@@ -85,7 +85,7 @@ private async Task<PayloadData> DoReceiveAsync(CancellationToken cancellationTok
 			if (m_end - m_offset < 4)
 			{
 				if (m_end - m_offset > 0)
-					Array.Copy(m_buffer, m_offset, m_buffer, 0, m_end - m_offset);
+					Buffer.BlockCopy(m_buffer, m_offset, m_buffer, 0, m_end - m_offset);
 				m_end -= m_offset;
 				m_offset = 0;
 			}
@@ -140,7 +140,7 @@ private async Task<PayloadData> DoReceiveAsync(CancellationToken cancellationTok
 			var readData = m_buffer;
 			if (payloadLength > m_buffer.Length)
 				readData = new byte[payloadLength];
-			Array.Copy(m_buffer, m_offset, readData, 0, m_end - m_offset);
+			Buffer.BlockCopy(m_buffer, m_offset, readData, 0, m_end - m_offset);
 			m_socketAwaitable.EventArgs.SetBuffer(readData, 0, 0);
 
 			// read payload