Phil Evans and Laurence Tyler report from the Leicester Swift team that extractor core dumps when extracting an event file from multiple inputs if the second file has only 1 event. They tracked the problem to a floating divide by zero due to an uninitialized variable in xclock called from w_events. I fixed this by removing the xclock call because it makes no sense in w_events because we don't know the total number of events which will be written. Fixed in v4.71.
Keywords: HEAsoft, xselect, Swift