7b938abe2b
Mesh had invalid face indices (number too high). On Separate in Edit Mode it crashed. Two fixes: - The Material properties viewer just showed the last material in the index array. Now it shows nothing, to indicate it's an invalid selected material. - Crash was caused by array copy magic, not checking the active index properly. (No assert, no warning prints, I think cases like this can happen too easily, and this way user gets notified nicely and can fix it).