94e8052 wasn't right either: we need any overflow item appearing in the
range, so increment the record number before the test, but don't compare
against the stop recno in the test, do that afterward.  In other words,
if we're past "start", then we need to record, and if we're past stop,
we quit looking.
Copy the corrupted file before salvaging it, the dd command to
reproduce the corruption is too painful to build every time I
want to debug one of these.
One more try to get the range check for overflow records correct.
Decrement the RLE *before* setting the number of skip items to 0.