clone preparedgeom + flip add_intersections if necessary

geo/src/algorithm/relate/geomgraph/index/prepared_geometry.rs

@@ -27,6 +27,7 @@ use rstar::{RTree, RTreeNum};
 /// assert!(prepared_polygon.relate(&contained_line).is_contains());
 ///
 /// ```
+#[derive(Clone)]
 pub struct PreparedGeometry<'a, F: GeoFloat + RTreeNum = f64> {
     geometry_graph: GeometryGraph<'a, F>,
 }

geo/src/algorithm/relate/geomgraph/index/rstar_edge_set_intersector.rs

@@ -41,7 +41,12 @@ where
 
                     let edge_0 = &mut e0[mi];
                     let edge_1 = &mut e1[mx - (mi + 1)];
-                    segment_intersector.add_intersections(edge_0, mi, edge_1, mx);
+
+                    if segment_0.edge_idx > segment_1.edge_idx {
+                        segment_intersector.add_intersections(edge_1, mx, edge_0, mi);
+                    } else {
+                        segment_intersector.add_intersections(edge_0, mi, edge_1, mx);
+                    }
                 }
             }
         }