修复bug

src/graphic/Util/MathUtil.js

@@ -1560,6 +1560,8 @@ export default class MathUtil {
 
   getIndexForCurvesPoints(position, points) {
     let minDis = null;
+    let minDisToPoint = null;
+    let minPointIndex = -1;
     let index = -1;
     for (let i = 0; i < points.length - 1; ++i) {
       const line = this.createLine1(points[i], points[i + 1]);
@@ -1571,8 +1573,26 @@ export default class MathUtil {
           index = i;
         }
       }
+      if (minDisToPoint == null) {
+        minDisToPoint = mathUtil.getDistance(position, points[i]);
+        minPointIndex = i;
+      } else if (minDisToPoint > mathUtil.getDistance(position, points[i])) {
+        minDisToPoint = mathUtil.getDistance(position, points[i]);
+        minPointIndex = i;
+      }
+    }
+    if ((index = -1)) {
+      if (
+        minDisToPoint >
+        mathUtil.getDistance(position, points[points.length - 1])
+      ) {
+        return points.length - 1;
+      } else {
+        return minPointIndex;
+      }
+    } else {
+      return index;
     }
-    return index;
   }
 
   // //获取一组点的偏移