Thanks for your answer.
It was the second documentation I was previously looking at. It's also this document that I found referred in the API-doc.
I think the documentation is a bit ambigious.
"all overlapping segments are reduced to a single segment, and segments are split at intersection points. Output paths are created for connected sequences of segments"
Then the following illustration I think shows that the selfintersecting path (3) will be diveded into three segments (6, 7, 8).
Maybee the documentation needs to be updated?