Ungroup causes entire group object to disappear (nested 3dboxes)

[Grant Edwards]

Version 0.47 under Gentoo Linux.

I have a group of 3D boxes. When I select the group object and apply
the ungroup operation, the entire group simply vanishes. Example .svg
file is attached.

[Grant Edwards (grant-edwards)]

The following output appears in the terminal window where inkscape was started:

** (inkscape:11016): WARNING **: Non-side item encountered as child of a 3D box.

** (inkscape:11016): WARNING **: Non-side item encountered as child of a 3D box.

** (inkscape:11016): WARNING **: Non-side item encountered as child of a 3D box.

** (inkscape:11016): WARNING **: Non-side item encountered as child of a 3D box.

** (inkscape:11016): WARNING **: Non-side item encountered as child of a 3D box.

[su_v (suv-lp)]

reproduced with Inkscape 0.47+devel r9225 on OS X 10.5.8

[su_v (suv-lp)]

these are nested 3d boxes (3D Box inside a 3D Box).

«Nested Boxes
Inkscape does not prevent you from creating a box inside another box Group. This can lead to strange behavior. »
<http://tavmjong.free.fr/INKSCAPE/MANUAL/html/Shapes-Boxes.html>

One can 'ungroup' the top 3D Box with these steps:
1) enter the top 3D Box (using the context menu),
2) select all 3dboxes inside this group,
3) cut them,
4) leave the group again (double-click on empty canvas) and
5) paste in place.

[Grant Edwards (grant-edwards)]

Oops. I wasn't aware that I had nested 3D boxes.

[su_v (suv-lp)]

"Known" limitation of the current implementation of 3dboxes (as regular SVG groups with special attributes).

Please raise the bug importance if you think Inkscape needs to implement a kind of guard which checks each time a group is entered whether adding new objects is "permitted" (if group has 'sodipodi:type="inkscape:box3d"' attribute, don't allow adding (nested) 3dboxes).