How can I properly implement QSortFilterProxyModel.parent to handle a virtual column?

[d_stranz]

@Unai: For some reason, the forum put both of your posts into the "Moderation queue" for approval before they could become visible to the rest of the users. No idea why. I deleted the duplicate post and approved this one. Sorry about that.

I have created proxies with virtual columns, but in C++. I'll have to read through your code later and see if anything jumps out. There is a logical issue of what to do with "map to source" when the source index doesn't exist, and I think I have simply returned an invalid index. If you are relying on a pointer to something being stored in the QModelIndex, and that pointer is null, then that could certainly cause a segfault.

*Edit: You define (and access) a "self._parents" list (dictionary? I'm not a python expert), but I don't see anywhere that you are putting anything into this list. So calling self._parents[index] is probably the source of the crash.