Adding a comment would certainly not be a bad idea.
It is indeed ignoring the exception. That exception can only come from inside the tlog#iterate method and not from 'f', so when it happens it's ok to pretend this was the last entry we could supply during catchup.
At this place I don't really care wether the exception indicates a real TLogCheckSumError that aborted the iterate or wether it happens because the last entry in the tlog is concurrently being written and read, I just don't want this to accidently close the connection.