Details
Description
The crash seems to happen when using the OnDemand render policy and there's a scene update (but only in certain situations; we noticed this when changing a material's texture).
It only happens when the scene is in a QQuickWidget (it's not reproducible with QQuickView).
I could only reproduce this with Qt 5.14 (Qt 5.12 seems to work fine).
A simple test case and the stack trace are attached.