修改绘制报错

src/common/js/common.js

@@ -84,7 +84,7 @@ const handlerDrawing = function (PolyType, tooltipNum) { //（传入操作的Dra
                     null;
             }
             // }
-            if (DrawHandler.polyline && DrawHandler.isDrawing) {
+            if (DrawHandler.polyline && DrawHandler.polyline.positions && DrawHandler.isDrawing) {
                 let p = [...DrawHandler.polyline.positions]
                 if (PolyType == "Polygon") { //画面时，需要首尾相连
                     p.push(p[0])