From 925762da0475af3fbf475cf3c3705afdff3e5f40 Mon Sep 17 00:00:00 2001
From: Iskren Chernev <iskren.chernev@gmail.com>
Date: Thu, 31 Oct 2013 11:30:32 -0700
Subject: [PATCH] Fixed cloning a modified duration

Storing the _input for creating a duration doesn't work for cloning when the
original duration is modified, because input no longer corresponds to the new
duration. Instead use the ms, days and month values which uniquely identify
a duration.

This also happens to fix #1242
---
 moment.js               | 18 ++++++++++--------
 test/moment/duration.js |  6 ++++--
 2 files changed, 14 insertions(+), 10 deletions(-)

diff --git a/moment.js b/moment.js
index 4858e241b..fd8424579 100644
--- a/moment.js
+++ b/moment.js
@@ -298,9 +298,6 @@
             seconds = normalizedInput.second || 0,
             milliseconds = normalizedInput.millisecond || 0;
 
-        // store reference to input for deterministic cloning
-        this._input = duration;
-
         // representation for dateAddRemove
         this._milliseconds = +milliseconds +
             seconds * 1e3 + // 1000
@@ -1559,9 +1556,7 @@
 
     // duration
     moment.duration = function (input, key) {
-        var isDuration = moment.isDuration(input),
-            isNumber = (typeof input === 'number'),
-            duration = (isDuration ? input._input : (isNumber ? {} : input)),
+        var duration = input,
             // matching against regexp is expensive, do it on demand
             match = null,
             sign,
@@ -1570,7 +1565,14 @@
             timeEmpty,
             dateTimeEmpty;
 
-        if (isNumber) {
+        if (moment.isDuration(input)) {
+            duration = {
+                ms: input._milliseconds,
+                d: input._days,
+                M: input._months
+            };
+        } else if (typeof input === 'number') {
+            duration = {};
             if (key) {
                 duration[key] = input;
             } else {
@@ -1609,7 +1611,7 @@
 
         ret = new Duration(duration);
 
-        if (isDuration && input.hasOwnProperty('_lang')) {
+        if (moment.isDuration(input) && input.hasOwnProperty('_lang')) {
             ret._lang = input._lang;
         }
 
diff --git a/test/moment/duration.js b/test/moment/duration.js
index d5e1d4baf..e0377054e 100644
--- a/test/moment/duration.js
+++ b/test/moment/duration.js
@@ -130,12 +130,14 @@ exports.duration = {
                 minutes: 9,
                 seconds: 20,
                 milliseconds: 12
-            });
+            }),
+            modified = moment.duration(1, 'day').add(moment.duration(1, 'day'));
 
-        test.expect(3);
+        test.expect(4);
         test.deepEqual(moment.duration(simple), simple, "simple clones are equal");
         test.deepEqual(moment.duration(lengthy), lengthy, "lengthy clones are equal");
         test.deepEqual(moment.duration(complicated), complicated, "complicated clones are equal");
+        test.deepEqual(moment.duration(modified), modified, "cloning modified duration works");
         test.done();
     },
 
-- 
2.47.2