Terminating execution of ROW_NUMBER() window function once criteria is met in Apache Derby

Hi,

I'm an undergraduate of University of Moratuwa, Sri Lanka. I'm interesting
in fixing the bug of terminating execution of ROW_NUMBER() window function
once criteria is met in Apache Derby Database Server which is described
under this <https://issues.apache.org/jira/browse/DERBY-3505> URL. But I
couldn't find relevant codes in the source folder. I greatly apppriciate if
you can provide some useful tips on ways to analyze the code.

Thank you,
Chanika Geeganage
Undergraduate
University of Moratuwa