QSqlQueryModel::headerData() relied on virtual indexInQuery() to
detect whether the requested column at row 0 mapped to an index in
the query. This failed when row 0 was a pending insert managed by
QSqlTableModel, and therefore not in the query.
The only thing that matters here is the column.
Task-number: QTBUG-29108
Change-Id: I3e0ae85ba223e444781ec8033386d394bb44f0e8
Reviewed-by: Andy Shaw <andy.shaw@digia.com>
Reviewed-by: Mark Brand <mabrand@mabrand.nl>