How much of being good with machines/computers is just not being afraid to push the buttons?
This reminds me of a time when I was in high school and an art teacher asked me to take a look at a computer cart she couldn't get working. I looked at it for a little while, pressed the power button on the monitor, and that fixed everything.
If you use a Repeater against a QAbstractItemModel and then remove data from the model, the delegate for that item automatically gets its index set to -1 and the item bindings get re-evaluated with that immediately before the delegate gets deleted. That's not the nicest design decision on the part of Repeater, but my code should have had the bounds check and there are workarounds for the other consequences.
Today's code edits involved adding a bunch of tiny little functions to support new features and adding a bounds check to a function that I'm amazed I wrote without one. Stuff mostly worked on the first try with the exception of the feature that exposed the lack of a bounds check (which worked once I fixed that). I also cleaned up some superfluous conditionals and did some other minor organizational tweaks.
Author of Typica software for coffee roasters.