Circular arc constructors return an empty geometry

Description

Some circular arc constructors return an empty geometry or an error message where they should return a valid degenerate arc geometry. A degenerate arc geometry means that either ICircularArc::IsLine or ICircularArc::IsPoint return TRUE. One example of where this problem occurs is for the ConstructTangentRadiusAngle method. In this method, if the radius is entered as zero, no message is returned and an empty geometry results.

Cause

This is a known problem.

Solution or Workaround