QTreeWidget->clear() causing crash after sort

[Chuk]

There is quite a bit of code, as the subclass is for drag and drop. It would probably be easier to give a url to the project...

But, I found it was caused by the signal currentItemChanged(current, previous), or just the way I was using it. I only made reference to current, and a quick "if (current)" fixed the problem. But why would the current item be null in one sort order but not the other? Is this a Qt Bug?

[marcel]

I think the selection might be cleared when sort order changes.
Have you checked that?

[Chuk]

I have not checked in code, but visually, the same line is highlighted when sort order is changed.

I can see how as items are removed, the selected item could be cleared. But why would it be different between sort orders? It is only the Descending sort order that I get the null current item, with or without a selection. It seems like it should happen in both sort orders or neither.

[wysota]

Where exactly do you call clear()?

[Chuk]

Where exactly do you call clear()?

In a refresh() function in the QDialog that contains the Tree. It's called when the app loads to initially populate the tree, and is then connected to a button to refresh the list at any time.

Clearing the list and iterating through a plugin list seems the easiest way to refresh, rather than checking for additions or deletions.

[wysota]

When you clear the widget, all its items will become invalid, so if you store a pointer to one (or more) of them somewhere, you can't use it anymore - you have to ask the widget for the item again. Because you never know what caused a slot to trigger, you should always check for validity of pointers you get as slot parameters.