Panicks with attempt to subtract with overflow when removing items

[PPakalns]

cursive_tree_view/src/lib.rs

Line 401 in e37b9b3

self.focus = cmp::min(self.focus, self.list.height() - 1);

When container is fully emptied by calling remove_item(row) subtraction overflow happens.

This happens only in debug mode due to additional Rust checks!