Comment 1 for bug 898318

For the record, this required changing how sub last_chunk() works, the SQL it executes, and we added an index over (ts,db,tbl) to the checksums table. Previously, we selected the max ts from the table, then got the row associated with that ts, but we have to use <= instead of = because of a bug in MySQL. But given that we also had to order those results DESC, in this cases that put the wrong table at the top of the list. So we would get the correct max ts but then the wrong table. This is fixed and tested now:

ok 46 - Checksum results partial t1, full t2
ok 47 - Resume from t1 when t2 is done