fix Transaction.sortOutputs

lib/transaction/transaction.js

@@ -899,16 +899,18 @@ Transaction.prototype.sortOutputs = function(sortingFunction) {
 };
 
 Transaction.prototype._newOutputOrder = function(newOutputs) {
-  var changeIndex = 0;
+  var isInvalidSorting = (this.outputs.length !== newOutputs.length ||
-  var length = this.outputs.length;
+                          _.difference(this.outputs, newOutputs).length !== 0);
-  while (changeIndex < length && this.outputs[this._changeIndex] !== newOutputs[changeIndex]) {
+  if (isInvalidSorting) {
-    changeIndex++;
-  }
-  if (changeIndex === length) {
     throw new errors.Transaction.InvalidSorting();
   }
+
+  if (!_.isUndefined(this._changeIndex)) {
+    var changeOutput = this.outputs[this._changeIndex];
+    this._changeIndex = _.findIndex(newOutputs, changeOutput);
+  }
+
   this.outputs = newOutputs;
-  this._changeIndex = changeIndex;
   return this;
 };
 

test/transaction/transaction.js

@@ -812,15 +812,20 @@ describe('Transaction', function() {
 
     it('fails if the provided function does not work as expected', function() {
       var sorting = function(array) {
-        return [];
+        return [array[0], array[1], array[2]];
       };
       expect(function() {
         transaction.sortOutputs(sorting);
       }).to.throw(errors.Transaction.InvalidSorting);
     });
 
-
+    it('shuffle without change', function() {
-
+      var tx = new Transaction(transaction.toObject()).to(toAddress, half);
+      expect(tx.getChangeOutput()).to.be.null;
+      expect(function() {
+        tx.shuffleOutputs();
+      }).to.not.throw(errors.Transaction.InvalidSorting);
+    })
   });
 
   describe('clearOutputs', function() {