The bug in the offset correction code for the 'shrink region from
below' case can easily case an assert(foundregion->offset == offset)
to trigger (if the blocks are touched afterwards, e.g. on fork())
as the offsets become wrong. This commit is a fix & regression test.
Change-Id: I28ed403e3891362a2dea674a49e786d3450d2983
274fdff60c