[Interest] void QTableView::setSpan spans of 0 and 1?

[Carl Schumann]

Qt community,

I am in the process of upgrading from Qt 4.5.0 to Qt 4.8.0.   Apparently 
Qt 4.8.0's void QTableView::setSpan complains about setting the span to 
0 or 1, where 4.5.0 did not.  So I have some questions please.

1. To what if anything should I set the span to for a cell that is 
occluded by an adjacent cell's span?
2. If a cell is changed such that it used to span 2 but now should not 
span into the 2nd cell, to what should I set its and the adjacent cells 
span?  I would think 1, but that generates complaints to to the terminal 
window.

Thanks for any help.

Sincerely,
Carl Schumann