PMO should only look at the write_output_state_to_file item, not the filename(s)

[nancycollins]

if you have this in your PMO namelist:

   write_output_state_to_file = .false.
   output_state_files         = ""

then helen's recent fix prevents a coredump and it exits with a message saying you have to specify an output filename.

but if you have this:

   write_output_state_to_file = .false.
   output_state_files         = "bob.nc"

then pmo runs fine, and doesn't create an output file. the logic here is broken.

Describe the bug

1. download a caminput.nc from the /glade/p/cisl/dares/DART_test_cases into your models/cam-fv/work dir
2. build the cam-fv executables
3. in input.nml, change write_output_state_to_file to .false.
4. run - it finishes fine and doesn't create perfect_restart.nc
5. in input.nm, change output_state_files to "" (2 double quotes)
6. run - it gives you an error that you have to specify an output file (or it coredumps if you don't have helen's latest update downloaded)

it should ignore the filename if you're not writing output.

[hkershaw-brown]

Also the default nameslist values for the files are " ". I agree this logic is broke.

There's a todo in the code from some time ago.

!> @todo FIXME  if nfilesout == 0 and write_output_state_to_file is .false.
!> that shouldn't be an error.  if nfilesin == 0 and read_input_state_from_file
!> is false, that also shouldn't be an error.  (unless you're writing the mean
!> and sd, and then maybe we should have a different name for output of input values.

off the top of your head do you know what the concern is with mean and sd? (edit grammar).

[nancycollins]

the lack of uppercase leads me to believe this is my comment, but i'm having problems remembering what the mean and sd have to do with anything.

PMO doesn't give you the option to specify 'stages' - you get the output state or you don't. if your model is subroutine-callable and you're using a single file, you get multiple timesteps in a single file. i guess i'd ignore the line after that opening paren. also, there's no closing paren which is sloppy.