[Interest] Why can't I sort QTreeView?

[Matthew Woehlke]

On 11/09/2019 15.52, Matthew Woehlke wrote:
> I have a QTreeView. The model is set to a subclass of
> QAbstractSortFilterProxyModel, which is in turn proxying a subclass of
> QAbstractItemModel.
> 
> I've set sortingEnabled, but for the life of me, I can't get sorting to
> actually work (under user control); no sorting indicator is shown, and
> clicking on the column headers does nothing.
> 
> What am I missing?

Um.. okay, answering my own question, sort-of, QHeaderView::restoreState
borked it somehow. So, I can work around it by nuking the "bad"
settings, but what did QHeaderView::restoreState to bork it, and how
would I fix it in code?

-- 
Matthew