Fix boundary error in make_logical.
Fix boundary error in make_logical.

Previously, the test was done for maxLine < 0, disregarding maxChunk
value.  There are however situations in which maxLine >= 0 and maxChunk
is still < 0.  In this case binary search loop was entered with left ==
current == right == 0, and an empty chunkMap was accessed.

run4flat/Primo,run4flat/Primo