Issue 714 Bugfix: need to check if optional arguments are present bef…

…ore assigning them to a variable

src/MPP/mpp_land.F

@@ -140,21 +140,18 @@ subroutine LOG_MAP2d()
   end  subroutine log_map2d
 
 
-  !old subroutine MPP_LAND_INIT(flag, ew_numprocs, sn_numprocs)
   subroutine MPP_LAND_INIT(in_global_nx,in_global_ny)
 !    ### initialize the land model logically based on the two D method.
 !    ### Call this function directly if it is nested with WRF.
     implicit none
     integer, optional :: in_global_nx, in_global_ny
     integer :: ierr, provided
-    integer :: ew_numprocs, sn_numprocs  ! input the processors in x and y direction.
     logical mpi_inited
 
-    global_nx = in_global_nx
-    global_ny = in_global_ny
-
-    ! left_right_np = ew_numprocs
-    ! up_down_np  = sn_numprocs
+    if (present(in_global_nx) .and. present(in_global_ny)) then
+       global_nx = in_global_nx
+       global_ny = in_global_ny
+    end if
 
     call mpi_initialized( mpi_inited, ierr )
     if ( .not. mpi_inited ) then