Brief summary of bug

In traditional transient pft simulations with use_crop = .false., %crop does not advance from 1850 values.

General bug information

CTSM version you are using:
ctsm1.0.dev012-4-ga344044

Does this bug cause significantly incorrect results in the model's science?
Yes.

Configurations affected:

• IHist with create_crop_landunit = .true. and use_crop = .false. (which requires do_transient_crops = .false.)
• All transient pft configurations with create_crop_landunit = .true. and use_crop = .false.

Details of bug

Relevant code:
in subgridMod.F90, function crop_patch_exists

Important details of your setup / configuration so we can reproduce the bug

Test that revealed the problem when I ran it twice:

1. in /glade/work/slevis/git/ctsm1.0.dev012/cime/scripts (baseline master)
2. in /glade/work/slevis/git/collapse_pfts/cime/scripts (branch collapse2gencrop: Collapse2gencrop branch: Allow the model to not need to read 16-pft datasets and rather read 78-pft datasets #483)

ERP_D.f10_f10_musgs.IHistClm50Bgc.cheyenne_gnu.clm-decStart

In the test's 2002 history files I found %crop from 2002 in the branch and from 1850 in the baseline.