**BUG** Concise problem statement: When importing a DXF, as BoardOutline and having "treat circle as hole on BoardOutLine layer" ticked on, all closed strings made of lines and arcs have the arcs transformed to straight lines, plus every element is mirrored. and/or When importing a revised file that has had the closed strings exploded to individual lines and arcs, some of the imported arcs are mirrored. When attempting to mirror them back, they are not inline with where they should be. Steps to reproduce bug: 1. Create DXF. Ensure it contains circles, closed line strings (made of arcs and lines) and individual lines and arcs 2. Import into EasyEDA with settings above 3. Results: all closed strings made of lines and arcs have the arcs transformed to straight lines every element is mirrored some of the imported arcs are mirrored Expected results: All shapes/lines/arcs/strings should be same orientation and shape as in the original DXF file Browser: Chrome