Merge branch 'stephenprice/correct_logic_in_seq_diag_glc_mct' (PR #7505)

Fix logic around g2x and x2g vector index calculation

This PR corrects the "first_time" logic around the calculation of
indices for the glc coupling vectors g2x and x2g. Because the calls to
x2g and g2x happen in budgets1 and budgets2, respectively, both sets of
indices need to be calculated at the same time if the first_time logic
is to be used so that these calculations only happen once. This fix has
been tested and confirmed working.

[BFB]

Author: jonbob

driver-mct/main/seq_diag_mct.F90

@@ -1355,15 +1355,24 @@ subroutine seq_diag_glc_mct( glc, frac_g, infodata, do_x2g, do_g2x )
 
     ip = p_inst
 
-    if( present(do_g2x))then  ! do fields from glc to coupler (g2x_)
+    if (first_time) then
 
-       if (first_time) then
+       ! we calc these both first rather then in their respective "if" constructs
+       ! below to avoid g2x indices not getting calculated (because the call to
+       ! x2g and g2x happen separately, in budgets1 and budgets2, respectively).
 
-          index_g2x_Fogg_rofl   = mct_aVect_indexRA(g2x_g,'Fogg_rofl')
-          index_g2x_Fogg_rofi   = mct_aVect_indexRA(g2x_g,'Fogg_rofi')
-          index_g2x_Figg_rofi   = mct_aVect_indexRA(g2x_g,'Figg_rofi')
+       ! indices needed for g2x
+       index_g2x_Fogg_rofl   = mct_aVect_indexRA(g2x_g,'Fogg_rofl')
+       index_g2x_Fogg_rofi   = mct_aVect_indexRA(g2x_g,'Fogg_rofi')
+       index_g2x_Figg_rofi   = mct_aVect_indexRA(g2x_g,'Figg_rofi')
 
-       end if
+       ! indices needed for x2g
+       index_x2g_Flgl_qice  = mct_aVect_indexRA(x2g_g,'Flgl_qice')
+       index_g2x_Sg_icemask = mct_avect_indexRA(g2x_g,'Sg_icemask')
+
+    end if
+
+    if( present(do_g2x))then  ! do fields from glc to coupler (g2x_)
 
        ic = c_glc_gr
        kArea = mct_aVect_indexRA(dom_g%data,afldname)
@@ -1382,13 +1391,6 @@ subroutine seq_diag_glc_mct( glc, frac_g, infodata, do_x2g, do_g2x )
 
     if( present(do_x2g))then  ! do fields from coupler to glc (x2g_)
 
-       if (first_time) then
-
-          index_x2g_Flgl_qice  = mct_aVect_indexRA(x2g_g,'Flgl_qice')
-          index_g2x_Sg_icemask = mct_avect_indexRA(g2x_g,'Sg_icemask')
-
-       end if
-
        l2gacc_lx_cnt_avg = prep_glc_get_l2gacc_lx_cnt_avg() ! counter for how many times SMB flux accumulation has occured 
        ic = c_glc_gs
        kArea = mct_aVect_indexRA(dom_g%data,afldname)