Disabled movement of the first column in QTreeView by user's actions

In Qt 4 movement of first column by user's actions was enabled, but in Qt 5.1.1 this feature was disabled. User can't move first column in QTreeView when QHeaderView::moveSection works well. But after moving in code that (root) column can't be moved by user's actions all the same.

May be it's not a bug and it's a decision of developers. But it would be nice if this behavior can be configured. I mean enabling/disabling of moving of first column in QTreeView.