TryReadByte causes a panic

[syllith]

Seemingly randomly, I get a crash with this call stack:

panic: runtime error: index out of range [256] with length 256

goroutine 40 [running]: bufio.(Reader).ReadByte(0xc000580360) C:/Program Files/Go/src/bufio/bufio.go:271 +0xa5 github.com/ziutek/telnet.(Conn).tryReadByte(0xc0016d2000) C:/Users/kinlougn/go/pkg/mod/github.com/ziutek/telnet@v0.1.0/conn.go:230 +0x25 github.com/ziutek/telnet.(*Conn).Read(0xc0016d2000, {0xc000ce7e28, 0x100, 0xc000ce7e60?}) C:/Users/kinlougn/go/pkg/mod/github.com/ziutek/telnet@v0.1.0/conn.go:299 +0x45 breeze/avocent.continuouslyReadOutput() C:/Users/kinlougn/Github Repos/Breeze/avocent/avocent.go:60 +0x66 created by breeze/avocent.Connect in goroutine 10 C:/Users/kinlougn/Github Repos/Breeze/avocent/avocent.go:42 +0x105 exit status 2

This is the code that I'm using to call it. Am I doing something wrong, or is this a bug?

func continuouslyReadOutput() {
    buf := make([]byte, 256)
    for {
        select {
        case <-done:
            return // Stop the goroutine when the connection is closed
        default:
            n, err := conn.Read(buf)
            if err != nil {
                if err == io.EOF {
                    log.Println("Connection closed by the server.")
                    return
                }
                log.Printf("Error reading from connection: %v", err)
                continue
            }
            if n > 0 {
                output := string(buf[:n])
                accumulatedOutput.WriteString(output)
            }
        }
    }
}

[michalderkacz]

As the panic is inside bufio.(*Reader).ReadByte and the ReadByte function tries to read a byte from buf[len(buf)] it seems to me that the same bufio buffer was used concurrently. telnet.Conn cannot be used concurrently by multiple goroutines. Maybe this is your problem.