duplicate_vertices silently consumes indices about bevy HOT 1 OPEN

The way I see this function is:
It expands the vertices so that no vertex position is reused. Therefore no index appears twice in the index array and may only order the vertices. Now order the vertices array and you dont need the index data anymore.

This can obviously be better documented, but this side effect can be implied with some knowledge about the rasterization process. But - yes - as you have suggested, its only implicit.
I would argue expand_vertices, or even something like integrate_indices is a better name, though. There are probably even better ones.

from bevy.