Correct an oversight in df6d345bb4: without proportional editing, all
the transform data is "selected" by definition. This means that the
assumption "the selected data is sorted first in the array" is
trivially true, without calling any sorting function. So instead of
using the sorted index map in these cases, just fall back to regular
iteration.
To make the code handle this nicely, I made two "foreach" functions.
The first one transparently uses the sorted index map when available,
and performs regular iteration otherwise. The second function only
visits the selected items.
This makes the usage of these functions clearer, and the fact that
selected items are expected to be sorted first (either trivially or
explicitly) can be documented in a central place.
Pull Request: https://projects.blender.org/blender/blender/pulls/140720
de22f32656