Not rendering half siblings

[KentGrigo]

When not all of the parents are shared, the siblings are not rendered.
To reproduce, create Brother, Sister, Half-Brother, Father, and Mother.
Select Brother and add the parents, Father and Mother.
Add Sister as a sibling.
Select Half-Brother and add the parent, Mother, and leave father unknown.
When looking at the graph for Brother, Half-Brother is not rendered (even with All Relatives).

[KentGrigo]

I've added a small test to show the issue.
Just make a new family tree and import the attached .gramps file (GitHub didn't accept that file ending so I added .txt, just remove it).
Also, here are some screenshots of the test.

Note that I've set "View" to "All relatives".

Gramps file
topola-viewer-119.gramps.txt

As Brother

As Mother

As Half-Brother

[PeWu]

Thanks for the report. Yes, this is an actual problem and unfortunately the fix is not that trivial but definitely doable - requires layout changes in the topola library.
See also #84 and PeWu/topola#30