[FLASH-BUGS] EOS=0 species with PPM

[Peter Woitke]

Dear developers,

I think there is a bug in FLASH2.3 concerning EOS=0 species, in
/flash/source/hydro/explicit/split/ppm/hydro_1d.F90, lines 368-387:
The abundances are renormalised here without checking the EOS-property
(the marked lines were not there) ...

    do i = 1, nzn8

       sum = 0.e0

       do n = 1, ionmax
          if (EOSweight(n) > 0.1) then    ! changed PW
             xnav(i,n) = max(smallx, min(1.0, xnav(i,n)))
             sum = sum + xnav(i,n)
          endif
       enddo

       suminv = 1.e0/sum

       do n = 1, ionmax
          if (EOSweight(n) > 0.1) then    ! changed PW
             xnav(i,n) = max(smallx, min(1.e0, xnav(i,n)*suminv))
          endif
       enddo

    enddo

Whithout this fix, I got very strange results. I used these "species" for
the purpose to introduce other physical variables which need to be
advected, too. These values of these variables can be arbitrarily large,
e.g. 100. You can imagine what happened in the above loops ...

Have fun,

Peter Woitke