memory corruption in QAbstractItemView when editor state changes

The method QAbstractItemViewPrivate::updateEditorData loops over a list of editors in indexEditorHash. This list can possibly change during the loop. In case of such change, the iterator over the list becomes corrupt and loops until a segfault happens.

A possible case in which this happens is when an editor changes its state based on its value. For example an editor that becomes disabled when a certain value is set. If this value is then set in the loop, the editor becomes disabled, which triggers the opening of another editor in the subsequent field. This new editor is thus appended to the indexEditorHash which corrupts the iterator.