Fix #661

Author: vkarpov15

lib/document.js

@@ -975,16 +975,18 @@ Document.prototype.validate = function (cb) {
   var validating = {}
     , total = 0;
 
+  // gh-661: if a whole array is modified, make sure to run validation on all
+  // the children as well
   for (var i = 0; i < paths.length; ++i) {
     var path = paths[i];
     var val = self.getValue(path);
     if (val instanceof Array && !Buffer.isBuffer(val)) {
-      for (var i = 0; i < val.length; ++i) {
-        paths.push(path + '.' + i);
+      var numElements = val.length;
+      for (var j = 0; j < numElements; ++j) {
+        paths.push(path + '.' + j);
       }
     }
   }
-
   paths.forEach(validatePath);
   return promise;