Comment 4 for bug 1533551

I've made some tests. Its seems a floating point rounding or simple > / >= (if handled as 0.000001mm integers) question.

I've made two parallel (horizontal) segments, track width 0.25 and clearance 0.2, so their distance might be 0.45mm or more.

The lines' coords are

  (segment (start 59 38.45) (end 43 38.45) (width 0.25) (layer F.Cu) (net 10))
  (segment (start 59 38) (end 43 38) (width 0.25) (layer F.Cu) (net 16))

DRC drops 3 "two tracks too close" error on them. (for horizontal and two connecting segments)

If I replace 38.45 with 38.450001 (manual text editing of .kicad_pcb file), DRC errors gone.
(4 occurances: both ends of horizontal, and two connecting line endings)

If it's a floating point problem, a 0.0000005 constant should be added at comparision to enable the exact values.