In UDAF, possible for terminatePartial to be called without init?

[Aurora Skarra-Gallagher]

Hi,

I wrote a simple UDAF for Hive 0.6 and I had to include null checks in 
terminatePartial even though the object should never be null if init is always 
called before terminatePartial.

For instance, my init function:
        public void init() {
            result = new StringBuffer();
        }

My terminatePartial function:
        public String terminatePartial() {
            if (result == null) {
                return new String();
            }
            
            // Remove trailing comma, if string isn't blank
            if (result.length() > 0 && result.charAt(result.length() - 1) == 
',') {
                result.deleteCharAt(result.length() - 1);
            }
            
            return result.toString();
        }

If I don't have that initial null check, when the results are empty that I'm 
applying my UDAF to, I get a NullPointerException. It makes me think that 
terminatePartial can be called with no init call. Is that possible?

Thanks,
Aurora