Strange bug in assignment

[magicprinc]

JDK 17

MVEL evaluates

obj.bigDecimalField = Long.valueOf('999999999999999999');

as 1000000000000000000

Example:

    public void testBugReport () {
        final String bigValue = "999999999999999999";
        MyObj obj = new MyObj();
        final String expr = "obj.bigDecimalField = bigValue";

        MVEL.eval(expr, Map.of("obj", obj, "bigValue", bigValue));
        assertEquals(bigValue, obj.bigDecimalField.toString());// OK

        assertEquals(bigValue, new BigDecimal(Long.valueOf(bigValue).toString()).toString());// OK bug not in JDK

        MVEL.eval(expr, Map.of("obj", obj, "bigValue", Long.valueOf(bigValue)));
        assertEquals(bigValue, obj.bigDecimalField.toString());// Failure
        // Expected :999999999999999999
        // Actual   :1000000000000000000
    }

    /** POJO for testing of copying values between Fields and domain objects */
    public static class MyObj {
      BigDecimal bigDecimalField;
      BigInteger bigIntegerField;

      public void setBigDecimalField (BigDecimal v) { bigDecimalField = v;}

      public void setBigIntegerField (BigInteger v) { bigIntegerField = v;}
    }

[magicprinc]

Any chance?