rewrite calc_gli_term()

LDDsimulation/LDDsimulation.py

@@ -969,8 +969,11 @@ class LDDsimulation(object):
                 subdomain.pressure_prev_iter[phase].assign(pa0_interpolated)
                 subdomain.pressure_prev_timestep[phase].assign(pa0_interpolated)
 
-            # populate interface dictionaries with pressure values.
+            # populate interface dictionaries with pressure values. The calc_gli_method
+            # of each subdomain reads from the interface.pressure_values_prev
+            # and from interface.pressure_values dictionary so both need to be populated.
             subdomain.write_pressure_to_interfaces()
+            subdomain.write_pressure_to_interfaces(previous_iter = True)
             subdomain.write_solution_to_xdmf(#
                 file = self.solution_file[num], #
                 time = self.starttime,#