There was a bug in the move_weld_profile_planes function where
it would only move the profile plane involved in a "weld" if
certain vectors were not too small (less than BEVEL_EPSILON in
length). The intent of the code was just to avoid problems with
zero length normals (post normalization), and the normalize_v3
function indicates that with an exact 0.0f return, so there was
no need for an epsilon test.
The example file in the issue had a small-scale model (100 times
smaller than typical), which ended up causing the old code to
prevent moving the profile plane to where it belongs.
Pull Request: https://projects.blender.org/blender/blender/pulls/147898
d58afb615c