Posted by dellus on May 15, 2018; 10:01am
URL: https://forum.librecad.org/Anomalous-Circle-Trim-tp5715994p5715998.html

I have played around a bit and may have found an explanation.
I found no difference in behaviour between diameter and chord. I discovered that when you select the circle to be trimmed and nothing seems to happen, in fact something has happened, the circle has been cut at one point, and now is an arc (properties!), with start point same as endpoint, still looking like a circle. I suspected it might have something to do with the drawing direction of the circle. Further testing revealed that if you click the to be retained part of the circle at the counterclockwise end near the limiting entity, you get the desired result. Clicking at the clockwise end just cuts up the circle.