In-place mutation of properties is ignored if equal

[erkyrath]

If you have an array ls = [0, 1, 2] in a property, and you do ls[1] = 1.0, the change will not be saved to the database.

This is because the new property value compares equal to the old one ([0, 1.0, 2] == [0, 1, 2]). So the cache doesn't notice that anything's changed, so it doesn't bother to store the new value.