QMailMessageListModel::index() method returns valid QModelIndex object on invalid row/column parameters

From Maemo:

A bug in QMailMessageListModel class's method

QModelIndex index(int row, int column = 0, const QModelIndex &parent = QModelIndex()) const;

It returns valid QModelIndex on invalid model row/column parameters. That is if you specify a non-existing model row/column values it will still return a valid QModelIndex object (with specified row, column and a pointer to Model object).

For example: you are going through the model items and would like to mark the last row as DuiContentItem::SingleColumnBottom (in order to have bottom list corners rounded). You check if the next item index is valid by checking index.sibling(index.row() + 1, column).isValid() return value. In this case this expression will always return true.

Patch is attached.