fix：37850单独拖动基准点报错

src/graphic/Controls/MovePoint.js

@@ -199,10 +199,14 @@ export default class MovePoint {
   }
 
   updateBasePoint(position, basePointId) {
-    let lineGeometry = dataService.getLine(Settings.baseLineId);
-    let startPoint = dataService.getPoint(lineGeometry.startId);
-    let endPoint = dataService.getPoint(lineGeometry.endId);
-    lineGeometry = mathUtil.createLine1(startPoint, endPoint);
+    let lineGeometry,startPoint,endPoint
+    if(Settings.baseLineId){
+      lineGeometry = dataService.getLine(Settings.baseLineId);
+      startPoint = dataService.getPoint(lineGeometry.startId);
+      endPoint = dataService.getPoint(lineGeometry.endId);
+      lineGeometry = mathUtil.createLine1(startPoint, endPoint);
+    }
+ 
     let basePoint = dataService.getPoint(basePointId);
     let parent = basePoint.getParent();
     for (let key in parent) {