"Export Project to DXF" writes same OBJECTS section for every DXF file with fixed handles & LUNITS is incorrect

[iembry]

What is the bug or the crash?

Please refer to the analysis made by Manfred Moitzi (mozman) in the ezdxf issue that I filed (mozman/ezdxf#997):

"They write the same OBJECTS section for every DXF file with fixed handles, but the entities handles of the content are created dynamically. So the handles in the OBJCTS section (fixed handles) will never match the handles in the TABLES section (dynamic handles). And this is true for every entity in the OBJECTS section and therefor 85 or more errors in every DXF file they export!"

In addition, the $LUNITS variable is not correct. I exported a project to a DXF file with EPSG:2274 (units of US survey foot); however, the $LUNITS variable has an identifier of 2 (feet) rather than 21 (US Survey Feet). Please refer to https://ezdxf.readthedocs.io/en/stable/concepts/units.html for the appropriate table defining the units.

Steps to reproduce the issue

Go to File > Import/Export DXF > Export Project as DXF

The bug is actually in the underlying DXF exporter written in C++.

Versions

QGIS 3.34

Supported QGIS version

• I'm running a supported QGIS version according to the roadmap.

New profile

• I tried with a new QGIS profile

Additional context

Will you ensure that the $LUNITS variable correctly matches the units from the exported CRS?