修复bug

src/graphic/Renderer/Draw.js

@@ -1393,6 +1393,9 @@ export default class Draw {
 
   drawLine(vector) {
     const startReal = dataService.getPoint(vector.startId);
+    if (!startReal) {
+      return;
+    }
     const start = coordinate.getScreenXY(startReal);
     const endReal = dataService.getPoint(vector.endId);
     const end = coordinate.getScreenXY(endReal);