mb=0 fails in Higgs-coupling initialization

[kilian]

For summing over partons, it should be possible to set mb=0. However, in the SM and its variants this triggers an arithmetic exception in the Higgs-coupling initialization functions:

Runtime Error: *** Arithmetic exception: Floating divide by zero - aborting
sm_physics.f90, line 272: Error occurred in SM_PHYSICS:FAUX
sm_physics.f90, line 323: Called by SM_PHYSICS:TRI_I1
../../../../trunk/src/models/parameters.SM.f90, line 208: Called by PARAMETERS_SM:IMPORT_FROM_WHIZARD

This case should be properly caught (and maybe mtop=0 as well).

The problem is absent when using gfortran (-O3), but triggers with nagfor (no optimization).

[Juergen Reuter]

Done in r2820. Strangely enough, mh = 0 or mz = 0 do not crash in the parameter files. But ok. Closing.