correct regularization (#4670)

Author: simone-silvestri

src/ImmersedBoundaries/immersed_boundary_condition.jl

@@ -79,12 +79,12 @@ end
 """
 function regularize_immersed_boundary_condition(bc::IBC, grid, loc, field_name, prognostic_field_names)
 
-    west   = loc[1] === Face ? nothing : regularize_boundary_condition(bc.west,   grid, loc, 1, LeftBoundary,  prognostic_field_names)
-    east   = loc[1] === Face ? nothing : regularize_boundary_condition(bc.east,   grid, loc, 1, RightBoundary, prognostic_field_names)
-    south  = loc[2] === Face ? nothing : regularize_boundary_condition(bc.south,  grid, loc, 2, LeftBoundary,  prognostic_field_names)
-    north  = loc[2] === Face ? nothing : regularize_boundary_condition(bc.north,  grid, loc, 2, RightBoundary, prognostic_field_names)
-    bottom = loc[3] === Face ? nothing : regularize_boundary_condition(bc.bottom, grid, loc, 3, LeftBoundary,  prognostic_field_names)
-    top    = loc[3] === Face ? nothing : regularize_boundary_condition(bc.top,    grid, loc, 3, RightBoundary, prognostic_field_names)
+    west   = loc[1] === Center ? regularize_boundary_condition(bc.west,   grid, loc, 1, LeftBoundary,  prognostic_field_names) : nothing
+    east   = loc[1] === Center ? regularize_boundary_condition(bc.east,   grid, loc, 1, RightBoundary, prognostic_field_names) : nothing
+    south  = loc[2] === Center ? regularize_boundary_condition(bc.south,  grid, loc, 2, LeftBoundary,  prognostic_field_names) : nothing
+    north  = loc[2] === Center ? regularize_boundary_condition(bc.north,  grid, loc, 2, RightBoundary, prognostic_field_names) : nothing
+    bottom = loc[3] === Center ? regularize_boundary_condition(bc.bottom, grid, loc, 3, LeftBoundary,  prognostic_field_names) : nothing
+    top    = loc[3] === Center ? regularize_boundary_condition(bc.top,    grid, loc, 3, RightBoundary, prognostic_field_names) : nothing
 
     return ImmersedBoundaryCondition(; west, east, south, north, bottom, top)
 end