Automap rendering generates inconsistent corners depending on direction of lines

Important information Windows 10 latest master / did you download a release or did you compile yourself?

Describe When rendering doors on the automap, the rendered "square" is inconsistent: one of the corners is "rounder" than the rest, giving the overall square a weird appearance. The effect can be seen on mostly any automap zoom level so it appears to be an inconsistency on the rendering logic,

I noticed this same behavior seems to happen on all such corners, regardless if they are for doors, pillars, or even wall corners.

To Reproduce Steps to reproduce the behavior:

1. Open automap
2. Check corner rendering inconsistency

Expected behavior The edges should be rendered equally regardless of direction:

Screenshots