Cherry-pick stack overflow fix from 5.4.x branch

    Author: Kamil Rojewski <kamil.rojewski@gmail.com>
    Date:   Wed Aug 13 10:38:38 2014 +0200

    fix for stack overflow

    Recursion in item mapping iterator caused a stack overflow for
    large datasets.

    Task-number: QTBUG-40153
    Change-Id: I693798de0ecfd3a920a3dd270172ce7ec3c13d8d
Reviewed-by: Jędrzej Nowacki <jedrzej.nowacki@digia.com>