fix issue 77: process the last package before handle eof error

.gitignore

@@ -20,3 +20,6 @@ classes
 *.swp
 
 vendor/
+
+# vscode
+.vscode/

session.go

@@ -631,6 +631,13 @@ func (s *session) handleTCPPackage() error {
 					log.Infof("%s, session.conn read EOF, client send over, session exit", s.sessionToken())
 					err = nil
 					exit = true
+					if bufLen != 0 {
+						// as https://github.com/apache/dubbo-getty/issues/77#issuecomment-939652203
+						// this branch is impossible. Even if it happens, the bufLen will be zero and the error
+						// is io.EOF when getty continues to read the socket.
+						exit = false
+						log.Infof("%s, session.conn read EOF, while the bufLen(%d) is non-zero.", s.sessionToken())
+					}
 					break
 				}
 				log.Errorf("%s, [session.conn.read] = error:%+v", s.sessionToken(), perrors.WithStack(err))
@@ -638,12 +645,7 @@ func (s *session) handleTCPPackage() error {
 			}
 			break
 		}
-		if exit {
-			break
-		}
-		if 0 == bufLen {
-			continue // just continue if session can not read no more stream bytes.
-		}
+		if 0 != bufLen {
 			pktBuf.Write(buf[:bufLen])
 			for {
 				if pktBuf.Len() <= 0 {
@@ -671,6 +673,7 @@ func (s *session) handleTCPPackage() error {
 				pktBuf.Next(pkgLen)
 				// continue to handle case 5
 			}
+		}
 		if exit {
 			break
 		}