It would not use topological distances.
This was the case for Grease Pencil, Curves were right though (even
though both use the same code `curve_populate_trans_data_structs` /
`calculate_curve_point_distances_for_proportional_editing`)
So that calculation is actually right, the thing that made it fail for
Grease Pencil was that `init_proportional_edit` was calling
`set_prop_dist` with the `with_dist` argument as `true` [this would
overwrite the already calculated dist with the "plain", "non-
topological" distance again... leading to wrong values being used in
`calculatePropRatio`]
So to resolve, skip the `set_prop_dist` alltogether if T_PROP_CONNECTED
is used. Done for both Curves and Grease Pencil and move into own block.
Legacy Curve get their own codeblock (with a comment where their
topological distances are calculated).
Pull Request: https://projects.blender.org/blender/blender/pulls/138588
c86f5c2a64