fix: UDP packet should not return io.EOF

common/net/packet/packet_posix.go

@@ -3,7 +3,6 @@
 package packet
 
 import (
-	"io"
 	"net"
 	"strconv"
 	"syscall"
@@ -34,6 +33,7 @@ func (c *enhanceUDPConn) WaitReadFrom() (data []byte, put func(), addr net.Addr,
 		} else {
 			put()
 			put = nil
+			data = nil
 		}
 		if readErr == syscall.EAGAIN {
 			return false
@@ -48,9 +48,10 @@ func (c *enhanceUDPConn) WaitReadFrom() (data []byte, put func(), addr net.Addr,
 				addr = &net.UDPAddr{IP: ip[:], Port: from.Port, Zone: strconv.FormatInt(int64(from.ZoneId), 10)}
 			}
 		}
-		if readN == 0 {
-			readErr = io.EOF
-		}
+		// udp should not convert readN == 0 to io.EOF
+		//if readN == 0 {
+		//	readErr = io.EOF
+		//}
 		return true
 	})
 	if err != nil {