Sorting an array of items into stacking order fails for text items.
Their .index property always returns zero.
Other items work OK.
I was trying to fix the ordering of 'objects along paths' to use the stacking order so the user would have control of the pattern :-(
Edit : It's not a bug, it's a design problem. TextItem extends Item and overrides the .index property with a totally different meaning. The Item index is not accessible. :-(