Sysupgrade return code in 18.06 vs 17.01?

For Developers
9

That would convert the return code 10 into 1. But that does not solve the problem - sysupgrade should not return or return 0 when it is successful. But as it is, it sometimes returns 10 (1 with your patch) for a perfectly working sysupgrade.

The delicate problem is how to silence that false error, without suppressing real errors that could happen.
The following code would simulate "not returning" for both 10 and 0 exit codes, so essentially behaving like sysupgrade did in 17.01:

else
  ubus call system sysupgrade "{
    \"prefix\": $(json_string "$RAM_ROOT"),
    \"path\": $(json_string "$IMAGE"),
    \"command\": $(json_string "$COMMAND")
  }"
  if [ $? -eq 10 -o $? -eq 0 ]; then
    sleep 3600
    reboot
  fi
fi

But it is still ugly to suppress an arbitrary error code, I'd rather want to have the reason fully understood why this happens, and have it fixed at the source...