added back EOFPacket

Author: kerryjiang

src/SuperSocket.MySQL/MySQLConnection.cs

@@ -88,6 +88,17 @@ public async Task ConnectAsync(CancellationToken cancellationToken = default)
                         ? errorPacket.ErrorMessage
                         : "Authentication failed";
                     throw new InvalidOperationException($"MySQL authentication failed: {errorMsg} (Error {errorPacket.ErrorCode})");
+                case EOFPacket eofPacket:
+                    // EOF packet received, check if it indicates success
+                    if ((eofPacket.StatusFlags & 0x0002) != 0)
+                    {
+                        IsAuthenticated = true;
+                        break;
+                    }
+                    else
+                    {
+                        throw new InvalidOperationException("Authentication failed: EOF packet received without success status. Length: " + eofPacket.Length);
+                    }
                 default:
                     throw new InvalidOperationException($"Unexpected packet received during authentication: {authResult?.GetType().Name ?? "null"}");
             }

src/SuperSocket.MySQL/MySQLPacketFactory.cs

@@ -15,7 +15,8 @@ static MySQLPacketFactory()
             ClientInstance = new MySQLPacketFactory()
                 .RegisterPacketType<HandshakePacket>(-1)
                 .RegisterPacketType<OKPacket>(0x00)
-                .RegisterPacketType<ErrorPacket>(0xFF);
+                .RegisterPacketType<ErrorPacket>(0xFF)
+                .RegisterPacketType<EOFPacket>(0xFE);
         }
 
         private readonly Dictionary<int, Func<MySQLPacket>> _packetCreators = new();

src/SuperSocket.MySQL/Packets/EOFPacket.cs

@@ -0,0 +1,35 @@
+using System;
+using System.Buffers;
+using SuperSocket.ProtoBase;
+
+namespace SuperSocket.MySQL.Packets
+{
+    public class EOFPacket : MySQLPacket, IPacketWithHeaderByte
+    {
+        public byte Header { get; set; } = 0xFE;
+        public ushort WarningCount { get; set; }
+        public ushort StatusFlags { get; set; }
+
+        public int Length { get;  private set; }
+
+        protected internal override void Decode(ref SequenceReader<byte> reader, object context)
+        {
+            Length = (int)reader.Remaining;
+
+            if (!reader.TryReadLittleEndian(out ushort warningCount))
+                throw new InvalidOperationException("Failed to read WarningCount from EOFPacket.");
+
+            WarningCount = warningCount;
+
+            if (!reader.TryReadLittleEndian(out ushort statusFlags))
+                throw new InvalidOperationException("Failed to read StatusFlags from EOFPacket.");
+
+            StatusFlags = statusFlags;
+        }
+
+        protected internal override int Encode(IBufferWriter<byte> writer)
+        {
+            throw new NotImplementedException();
+        }
+    }
+}