small refactoring of routine lat_edge_correction

src/core/area.c

@@ -269,6 +269,8 @@ static double lat_edge_correction(
   // --> their sign indicates the ordering of vertices
   double scalar_base = scalar_product(norm_ab, base_vec);
 
+  int negative_correction_flag;
+
   // if the base point is on the same plane as a and b
   if (fabs(scalar_base) < 1e-11) {
 
@@ -280,22 +282,17 @@ static double lat_edge_correction(
     if (compute_norm_vector(middle_lat, pole, norm_middle)) return 0.0;
 
     double scalar_a = scalar_product(norm_middle, a);
-
-    if (scalar_a > 0)
-      return correction;
-    else
-      return - correction;
+    negative_correction_flag = scalar_a <= 0;
 
   } else {
 
     // compute the cosine between the edge norm vector and the lat edge middle
     // point
     double scalar_middle_lat = scalar_product(norm_ab, middle_lat);
-    if (scalar_middle_lat < 0)
-      return correction;
-    else
-      return - correction;
+    negative_correction_flag = scalar_middle_lat >= 0;
   }
+
+  return negative_correction_flag?-correction:correction;
 }
 
 double yac_pole_area(struct yac_grid_cell cell) {