Q: while((ch=Monitor.read()) != -1) {} will hang

[KurtE]

Describe the bug
It appears like Monitor.read() does not return -1 when the q is empty;

This hangs:

  int ch;
  if ((ch = Monitor.available()) > 0) {
    Monitor.print("Serial available:");
    Monitor.println(ch);
    uint8_t new_rototation = 0;
    while ((ch = Monitor.read()) != -1) {
      //Monitor.write(ch);
      if ((ch >= '0') && (ch <= '9')) {
        new_rototation = ch - '0';
      }
    }

This does not:

  int ch;
  if ((ch = Monitor.available()) > 0) {
    Monitor.print("Serial available:");
    Monitor.println(ch);
    uint8_t new_rototation = 0;
    while (Monitor.available()) {
      ch = Monitor.read();
      //Monitor.write(ch);
      if ((ch >= '0') && (ch <= '9')) {
        new_rototation = ch - '0';
      }
    }

Target board + cli verbose compilation output
Arduino UNO Q