fix: Avoid crash in isRemoved (#219)

[ninecc]

close #219

[nicolo-ribaudo]

Any chance you could add a test that fails before this change and passes with it?

(it'd be really nice to have one, but I understand if it's too difficult to write a small simple reproduction)

[ninecc]

I made a simple demo to reproduce the compile error.

Let me know if anything’s unclear or if you need more info!