A corner whose two curves end on separate points held together by a Coincident constraint (a line drawn to where an arc starts) is welded into one shared point before Fillet or a Chamfer rounds or cuts it, so it no longer reports that the corner must join two lines. Only a partner point held by nothing but that constraint is welded. Fixes #1208. Co-authored-by: DuBearte <DuBearte@users.noreply.github.com>