Fix code review by #165

Author: tangbc

demos/item-mode/build.js

@@ -342,7 +342,7 @@ function _typeof(obj) { if (typeof Symbol === "function" && typeof Symbol.iterat
 
         end = start + delta.keeps - 1;
 
-        if (end > delta.total) {
+        if (delta.total && end > delta.total) {
           end = delta.total - 1;
         }
 

demos/page-mode/build.js

@@ -1,6 +1,6 @@
 {
   "name": "vue-virtual-scroll-list",
-  "version": "1.4.5",
+  "version": "1.4.6",
   "description": "A vue component support big amount data list with high scroll performance.",
   "main": "dist/index.js",
   "files": [

demos/scroll-element/build.js

@@ -347,7 +347,7 @@
           start = index
         }
         end = start + delta.keeps - 1
-        if (end > delta.total) {
+        if (delta.total && end > delta.total) {
           end = delta.total - 1
         }