Commit 10ff9de91b introduced the
optimization of ignoring non-changes, but it overshot the mark.
It neglected to consider that QVariant's equality operator does not
compare the null flag. It also failed to consider that setData() has
a useful side effect of setting the generated flag in a column of a
pending INSERT. This is important when the application actually wants
a NULL to be inserted into the column.
Task-number: QTBUG-29217
Change-Id: I1368f7acc21eebfeb5a8d23746fc38f6f30fd395
Reviewed-by: Andy Shaw <andy.shaw@digia.com>
Reviewed-by: Mark Brand <mabrand@mabrand.nl>
33c212b7d2