Using the percent format in a decimalbox parsement and validation of negative percent value fails. We were able to track it back to zk.BigDecimal#$toString()

<window>
    <decimalbox format="#%"/>
</window>

When using the above zul and entering -3% in the decimalbox on validation it says - from a client error that we should enter a number instead of .-3

In the process a zk.BigDecimal is created with the value -3 and the set its precision to 2. The $toString() call on such a BigDecimal gives an invalid string representation.

var num = new zk.BigDecimal(-3);
num.setPrecision(2);
num.$toString();
// ".-3"