Fix weigth scale of A* being applied to the whole path and estimation

Attempt to fix #8584

(cherry picked from commit bd91730347b33fd88d3944dc63fed06655f0b736)

core/math/a_star.cpp

@@ -193,8 +193,7 @@ bool AStar::_solve(Point *begin_point, Point *end_point) {
 
 		Point *n = begin_point->neighbours[i];
 		n->prev_point = begin_point;
-		n->distance = _compute_cost(n->id, begin_point->id);
-		n->distance *= n->weight_scale;
+		n->distance = _compute_cost(begin_point->id, n->id) * n->weight_scale;
 		n->last_pass = pass;
 		open_list.add(&n->list);
 
@@ -238,8 +237,7 @@ bool AStar::_solve(Point *begin_point, Point *end_point) {
 
 			Point *e = p->neighbours[i];
 
-			float distance = _compute_cost(p->id, e->id) + p->distance;
-			distance *= e->weight_scale;
+			float distance = _compute_cost(p->id, e->id) * e->weight_scale + p->distance;
 
 			if (e->last_pass == pass) {
 				//oh this was visited already, can we win the cost?