[W.I.P.] Curve Tools plugin

[tkbd]

Thank you for update!

I tried and founded a crash.
How to recrate?

1. Make Curve by Line.
   
2. Change Curve Type to Bezier
   
3. Wings3D crash.
   

FYI: I updated curve plug-in from zip file install(Newest version).
Error Dialog message is:
Now might be a good time to save your work and restart Wings3D
and it get a following log

Code:

Dump written 2021-1-24_22-53
Version: 2.2.6.1
OS: macOS Mojave Version 10.14.6 (Build 18G7016)
GPU: Intel Inc. | Intel Iris OpenGL Engine
Window: {plugin,{curves,geom}}
Reason: function_clause

Short stack trace:
[{e3d_vec,add,2,[{file,"e3d_vec.erl"},{line,53}]},
{ct_bezier,'-calc_curve/1-fun-0-',6,[{file,"ct_bezier.erl"},{line,34}]},
{array,sparse_foldl_3,7,[{file,"array.erl"},{line,1684}]},
{ct_bezier,calc_curve,1,[{file,"ct_bezier.erl"},{line,30}]},
{curve_math,calc_curve,1,[{file,"curve_math.erl"},{line,124}]},
{curve_cmds,'-convert_curve/2-fun-0-',3,
             [{file,"curve_cmds.erl"},{line,1074}]},
{curve_sel,map_1,5,[{file,"curve_sel.erl"},{line,514}]},
{curve_sel,map,2,[{file,"curve_sel.erl"},{line,119}]},
{curve_cmds,convert_curve,2,[{file,"curve_cmds.erl"},{line,1072}]},
{wpc_curves,raw_command,4,[{file,"wpc_curves.erl"},{line,867}]},
{wings_wm,handle_event,3,[{file,"wings_wm.erl"},{line,1030}]},
{wings_wm,send_event,2,[{file,"wings_wm.erl"},{line,996}]},
{wings_wm,do_dispatch,2,[{file,"wings_wm.erl"},{line,888}]},
{wings_wm,dispatch_event,1,[{file,"wings_wm.erl"},{line,797}]},
{wings_wm,get_and_dispatch,0,[{file,"wings_wm.erl"},{line,683}]},
{wings,init_part2,3,[{file,"wings.erl"},{line,108}]},
{proc_lib,init_p_do_apply,3,[{file,"proc_lib.erl"},{line,249}]}]

Long stack trace:
[{e3d_vec,add,
          [{-1.2808961366362963,0.593822418282195,0.8892948274755286},none],
          [{file,"e3d_vec.erl"},{line,53}]},
{ct_bezier,'-calc_curve/1-fun-0-',6,[{file,"ct_bezier.erl"},{line,34}]},
{array,sparse_foldl_3,7,[{file,"array.erl"},{line,1684}]},
{ct_bezier,calc_curve,1,[{file,"ct_bezier.erl"},{line,30}]},
{curve_math,calc_curve,1,[{file,"curve_math.erl"},{line,124}]},
{curve_cmds,'-convert_curve/2-fun-0-',3,
             [{file,"curve_cmds.erl"},{line,1074}]},
{curve_sel,map_1,5,[{file,"curve_sel.erl"},{line,514}]},
{curve_sel,map,2,[{file,"curve_sel.erl"},{line,119}]},
{curve_cmds,convert_curve,2,[{file,"curve_cmds.erl"},{line,1072}]},
{wpc_curves,raw_command,4,[{file,"wpc_curves.erl"},{line,867}]},
{wings_wm,handle_event,3,[{file,"wings_wm.erl"},{line,1030}]},
{wings_wm,send_event,2,[{file,"wings_wm.erl"},{line,996}]},
{wings_wm,do_dispatch,2,[{file,"wings_wm.erl"},{line,888}]},
{wings_wm,dispatch_event,1,[{file,"wings_wm.erl"},{line,797}]},
{wings_wm,get_and_dispatch,0,[{file,"wings_wm.erl"},{line,683}]},
{wings,init_part2,3,[{file,"wings.erl"},{line,108}]},
{proc_lib,init_p_do_apply,3,[{file,"proc_lib.erl"},{line,249}]}]

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tkbd