Append buffered bytes only if read() was successful

Should solve #155

Author: facchinm

serialport.go

@@ -103,6 +103,12 @@ func (p *serport) reader() {
 
 		n, err := p.portIo.Read(ch)
 
+		if err != nil {
+			ch = append(buffered_ch.Bytes(), ch[:n]...)
+			n += len(buffered_ch.Bytes())
+			buffered_ch.Reset()
+		}
+
 		//if we detect that port is closing, break out o this for{} loop.
 		if p.isClosing {
 			strmsg := "Shutting down reader on " + p.portConf.Name
@@ -111,10 +117,6 @@ func (p *serport) reader() {
 			break
 		}
 
-		ch = append(buffered_ch.Bytes(), ch[:n]...)
-		n += len(buffered_ch.Bytes())
-		buffered_ch.Reset()
-
 		// read can return legitimate bytes as well as an error
 		// so process the bytes if n > 0
 		if n > 0 {