[fixed] Save issues after collapsing a hole.

[ajunkala]

Hmm... that seem to create a new problem. When I go to create a Cube it throws up an error. Here is the wings.dump

Dump written 2017-3-8_16-19
Version: 2.1.5
Window: geom
Reason: function_clause

Short stack trace:
[]

Long stack trace:
[{wings_we,is_open,
[{we,1,0,"Cube1",
{array,12,100,undefined,
{{{edge,0,1,5,1,3,1,2,4},
{edge,0,2,3,5,6,2,0,5},
{edge,0,4,1,3,8,0,1,9},
{edge,1,3,5,2,5,0,4,7},
{edge,1,5,2,1,10,3,0,8},
{edge,2,3,0,5,7,6,1,3},
{edge,2,6,3,0,9,1,5,11},
{edge,3,7,0,2,11,5,3,10},
{edge,4,5,1,4,4,2,9,10},
{edge,4,6,4,3,11,8,2,6}},
{{edge,5,7,2,4,7,4,8,11},
{edge,6,7,4,0,10,9,6,7},
undefined,undefined,undefined,undefined,undefined,
undefined,undefined,undefined},
10,10,10,10,10,10,10,10,10}},
none,none,
{6,
{3,1,
{1,0,{0,5,nil,nil},{2,3,nil,nil}},
{5,0,{4,8,nil,nil},nil}}},
{0,nil},
{array,8,10,undefined,{0,0,1,3,2,4,6,7,undefined,undefined}},
{array,8,10,undefined,
{{-1.0,-1.0,-1.0},
{-1.0,-1.0,1.0},
{-1.0,1.0,-1.0},
{-1.0,1.0,1.0},
{1.0,-1.0,-1.0},
{1.0,-1.0,1.0},
{1.0,1.0,-1.0},
{1.0,1.0,1.0},
undefined,undefined}},
{1,{wings_shape,no_folder,nil,nil}},
default,12,none,none,[]}],
[{file,"f:/unixlike/src/wings/src/wings_we.erl"},{line,179}]},
{wings_draw,prepare_fun,2,[{file,"wings_draw.erl"},{line,73}]},
{wings_dl,update_1,5,[{file,"wings_dl.erl"},{line,249}]},
{wings_draw,invalidate_dlists,1,[{file,"wings_draw.erl"},{line,54}]},
{wings_draw,refresh_dlists,1,[{file,"wings_draw.erl"},{line,48}]},
{wings,main_loop,1,[{file,"wings.erl"},{line,342}]},
{wings_wm,handle_event,3,[{file,"wings_wm.erl"},{line,952}]},
{wings_wm,send_event,2,[{file,"wings_wm.erl"},{line,918}]},
{wings_wm,do_dispatch,2,[{file,"wings_wm.erl"},{line,824}]},
{wings_wm,dispatch_event,1,[{file,"wings_wm.erl"},{line,725}]},
{wings_wm,get_and_dispatch,0,[{file,"wings_wm.erl"},{line,646}]},
{wings,init,1,[{file,"wings.erl"},{line,147}]}]