Once the missing ' below gets fixed, I'll comment on the results of the automatic testing. While that is happening, can I get J. S. Oishi , haoxu , and John Forbes to take a look at the PR? Specifically, could one of you make sure to run the new test problems and make the plots?
All of this looks good to me, except the ExternalBoundary condition stuff, which I don't have the knowledge to evaluate. I will go ahead and approve, but please note especially Sam Skillman and dcollins4096 that I haven't reviewed the code in src/enzo/ExternalBoundary_SetMagneticBoundary.C.
Originally I had treated the magnetic field as though it were the velocity. That's not entirely correct, and the physically correct solution will depend on the conductivity of the boundary. This caused significant noise at the corners. Treating the magnetic field like a scalar is still imperfect, but allows the code to run without generating extra inconsistencies. The big problem is that in the face, if changing the sign of the normal component is to be consistent, only solutions with zero normal component are consistent. For the Rayleigh Taylor problem, we want the pressure wave to be reflected at the bottom, but want a vertical field, which means the bottom cannot be a perfect conductor.
A more elaborate boundary should be developed as its need arises, that allows for the specification of the conductivity at the interface. Any new boundary should be able to reproduce this result.
This is a side-effect of testing that was necessary for the grackle 2.0 PR. I'm now going to work on updating the gold again with the MHD RT test above. Comments/approvals should continue as if everything is passing.
My patch seems to have fixed the spurious errors from grackle stuff. dcollins4096 mind adding an image generated from BinaryCollapseMHDCT/plots.py? It's in the full suite, which I don't run, and just want to see that the plot makes something useful to look at. After that, I'm okay with merging, and I'll update the gold tomorrow, hopefully combining this and the grackle stuff.