Fix FPE in AmgVector eta() implementation (ATLASRECTS-7646)
This time the FPE is caused by the case that the rho
component (=x*x + y*y
) is negligible compared to the z
component, such that
m-z = 0.0
to double-precision (where m = sqrt(rho*rho + z*z)
).
Taggin @christos