clipLon reduced longitudes by looping += 360 until in range. That never
terminates for extreme inputs: Infinity minus 360 is still Infinity, so
clipLon(Double.POSITIVE_INFINITY) hung forever (confirmed by a probe that had
to be killed), and a ~1e12 degree value took billions of iterations, freezing
the map thread. NaN came back as NaN either way.
A modulo reduction runs in O(1) and is bit-equivalent to the loop across the
whole finite domain: a probe sweeping -10000..10000 at 0.01 degree steps (2
million points) plus the boundary values -180/-179.999/0/179.999/180/180.001/
±360/±540 shows zero mismatches. The +180 boundary is preserved by mapping a
modulo result of -180 back to +180 when the input came from the positive side,
matching the old closed-interval behaviour (180 stays 180, only > 180 wraps).
Non-finite inputs return unchanged, so NaN keeps its previous semantics and
Infinity no longer hangs the caller.
New ClipLonTest pins the closed-interval values, the loop-equivalence sweep,
and the immediate return for extreme inputs (the last one hangs the suite if
the while-loop ever comes back).
mckero
ed1fe66892