Previously two distance-only clues whose circles didn't actually
intersect (real typewriter data isn't perfectly consistent, a
misplaced spotter or an off-by-a-bit distance reading is enough) just
gave up entirely, even when they were nearly touching.
solver.closest_compromise_point() picks the midpoint between each
circle's point facing the other, the standard notion of the closest
approach between two circles. It stays well-behaved even when the
centers are nearly coincident, unlike projecting along the center
line the way a real intersection's formula does, which diverges as
the centers get close while the radii stay far apart, exactly the
near-coincident case this is for.
The result is flagged rather than treated as a clean fix: Location
gained a field, set whenever solve_location() had to use this
fallback, cleared by any subsequent coord.setter call (manual or
solver), shown in the entity's status label and toasted after a
manual clue edit. Persisted through save/load.
Dominik Roth
980be86908