fix: #245

Author: leeluolee

lib/helper/watcher.js

@@ -242,6 +242,11 @@ var methods = {
       }
       watcher.fn.call(this, now, last, diff, trackDiff && trackDiff.oldKeyMap, trackDiff && trackDiff.dirty)
       if(watcher.once) this.$unwatch(watcher)
+    }else{
+      // #FIX 0.6.3 
+      if(now !== last){// 只有数组，且simplediff 判断为false才会
+        watcher.last =  _.clone(now)
+      }
     }
 
     return dirty;