NSLayoutManager setAllowsNonContiguousLayout misplaces caret

With setAllowsNonContiguousLayout set to YES, if I perform the following steps I get weird behaviour:

1. Sel开发者_如何学运维ect all text in the NSTextView
2. Hit backspace to remove all the text
3. Type a few lines of text
4. Trying using backspace to delete the text again

At step 4 the cursor jumps up to the line above and at a seemingly random point on the line, yet the actual glyphs are deleted from the correct location.

Is non-contiguous layout a bit experimental/buggy like this? If I turn it off things work as expected.

I'll file a bug report with Apple, but has anybody else seen this behaviour and worked around it?

A bug report is the right way to go, I think. From what I've heard is that non-contignuous layout has caused lots of headaches to some developers making them drop that feature again from their application. As nice as it sounds, it seemingly is hell of a thing to get to work right ... even for Apple.