id	summary	reporter	owner	description	type	status	milestone	component	version	severity	resolution	keywords	cc
11984	union_() generates self-intersecting polygon	max@…	Barend Gehrels	"I have a program which generates unions of a multipolygon and a ring. Sometimes, I have an identical point in the two shapes. The union_ result is a self-intersecting polygon.

Demo source attached. Output with Boost 1.58 and 1.60:

input multipolygon is valid
input ring is valid
result multipolygon is invalid: Geometry has invalid self-intersections. A self-intersection point was found at (-95, 60); method: t; operations: i/i; segment IDs {source, multi, ring, segment}: {0, 0, -1, 3}/{0, 0, -1, 6}
"	Bugs	closed	Boost 1.61.0	geometry	Boost 1.60.0	Problem	fixed