ab89e367da
Introduced with 5fff95f519.
There were several issues:
* The indices into `edit_points_vflag` are incorrect. They need to be offset
by the start offset of the drawing.
* The code was writing to `edit_points_vflag` even if the layer is locked.
But the size of the `edit_points_vflag` buffer is not counting locked layers.
Pull Request: https://projects.blender.org/blender/blender/pulls/129625