Round-12 regression: manually repeating the mouth point as a control
point made d3 emit a degenerate final path command (a zero-length L).
orient="auto" derives the marker angle from the direction of the LAST
path segment; a zero-length segment has none, so every head fell back
to 0° — pointing right. Fix: drop the manual repeat — curveBasis already
repeats the endpoint internally, so controls ending [Q, M] keep the
exact end tangent (the approach direction) AND a real final segment
(the straight Q→M stub). Left a comment in edgePathD so this never
regresses again.
amosblomqvist
d7790f895e