修复并集时行成的圆形网洞消失的问题

src/DatabaseServices/Contour.ts

@@ -132,11 +132,20 @@ export class Contour
                 let c1 = g[i];
                 let nextI = FixIndex(i + 1, g);
                 let c2 = g[nextI];
-                if (c1.Join(c2))
+
+                let status = c1.Join(c2);
+                if (status === Status.True)
                 {
                     g.splice(nextI, 1);
                     i--;
                 }
+                else if (status === Status.ConverToCircle)
+                {
+                    g.length = 0;
+                    let a = c1 as Arc;
+                    g.push(new Circle(a.Center, a.Radius));
+                    break;
+                }
             }
         }
         return Contour.GetAllContour(cuGroups);