Dynamic/linked Offset errors

[Nick]

Inset and offset sometimes gives errors. For example see attached image. If you will use Path->Stroke to path you will have the same result.

It is really important for me to have proper offset results because I'm writing an Gcode tools extension which uses Inkscape's offset.
I do not care about calculation time, but really need proper results.
I saw an use_slow_but_correct_offset_method variable that used in offset method. But have not found what it depends on or where it could be set up?

Is there any chance to get proper offset results? May be there's a way to rebuild the path before making offset, or use another function to do offset?

PS If I try to use Extensions->Generate from Path->Inset/Outset Halo there are also some errors but on the other side of the path.
By the way, I've found Halo's souse in Extensions dir, but found that it is built in Inkscape souse code.

[su_v (suv-lp)]

not reproduced with Inkscape 0.47 r22583 and 0.47+devel r9252 on OS X 10.5.8:

using 'Path > Inset' there are no nodes/subpaths created outside the original path.

[su_v (suv-lp)]

possibly related:
Bug #221049 “Path Inset Incorrect on Rounded Square ”
<https://bugs.launchpad.net/inkscape/+bug/221049>

[Nick (xepecine)]

Confirm that using Path->Inset gives correct result, but Path->Dynamic offset don't!

How can I use Path->Inset from an extension?

Now I'm creating a new object with following parameters:

inkscape:radius = radius
sodipodi:type = inkscape:offset
inkscape:original = d
...

I do not think that it is connected to bug with Ruonded square, because here some additional paths are created and those paths are closer to original path than offset radius.

[su_v (suv-lp)]

reproduced with Inkscape 0.47 and 0.47+devel r9252 on OS X 10.5.8

when creating a smaller offset, both 'Dynamic Offset' and 'Linked Offset' of the path result in adding an additional subpath outside of the original path.

[su_v (suv-lp)]

Still present with Inkscape 0.91+devel r14159 (on OS X 10.7.5).

[Samuel (qvarker)]

Still present in Inkscape 0.92.4 (stable version) on Windows 10 64 bits.