THcHelicity checks event number mismatch assuming the replay starts with the actual first event of the data (event number = 1). For the split replay, it would fail the check and disable the helicity decoding for the rest of the replay unless the replay starts with the actual first event of the data from 0th segment file.
The added line basically forces the check to always pass for the first replay event by re-initializing the variable (fEvNumCheck) to be the same as that event number.
THcHelicity checks event number mismatch assuming the replay starts with the actual first event of the data (event number = 1). For the split replay, it would fail the check and disable the helicity decoding for the rest of the replay unless the replay starts with the actual first event of the data from 0th segment file. The added line basically forces the check to always pass for the first replay event by re-initializing the variable (fEvNumCheck) to be the same as that event number.