From 9b5c97666aab2a0dbcb57891b045bb1365b8c651 Mon Sep 17 00:00:00 2001
From: jdalton <john.david.dalton@gmail.com>
Date: Sat, 11 Apr 2015 11:42:36 -0700
Subject: [PATCH] Ensure symbols work for `_.assign`, `_.defaults`, &
 `_.merge`.

---
 lodash.src.js | 36 ++++++++++++++++++++++++------------
 test/test.js  | 21 ++++++++++++++++++++-
 2 files changed, 44 insertions(+), 13 deletions(-)

diff --git a/lodash.src.js b/lodash.src.js
index ac4680e6c..c3a41fbb7 100644
--- a/lodash.src.js
+++ b/lodash.src.js
@@ -1777,8 +1777,10 @@
      * @returns {Object} Returns `object`.
      */
     function assignWith(object, source, customizer) {
+      var props = keys(source);
+      push.apply(props, getSymbols(source));
+
       var index = -1,
-          props = keys(source),
           length = props.length;
 
       while (++index < length) {
@@ -2573,22 +2575,32 @@
         return object;
       }
       var isSrcArr = isLength(source.length) && (isArray(source) || isTypedArray(source));
-      (isSrcArr ? arrayEach : baseForOwn)(source, function(srcValue, key, source) {
+      if (!isSrcArr) {
+        var props = keys(source);
+        push.apply(props, getSymbols(source));
+      }
+      arrayEach(props || source, function(srcValue, key) {
+        if (props) {
+          key = srcValue;
+          srcValue = source[key];
+        }
         if (isObjectLike(srcValue)) {
           stackA || (stackA = []);
           stackB || (stackB = []);
-          return baseMergeDeep(object, source, key, baseMerge, customizer, stackA, stackB);
+          baseMergeDeep(object, source, key, baseMerge, customizer, stackA, stackB);
         }
-        var value = object[key],
-            result = customizer ? customizer(value, srcValue, key, object, source) : undefined,
-            isCommon = result === undefined;
+        else {
+          var value = object[key],
+              result = customizer ? customizer(value, srcValue, key, object, source) : undefined,
+              isCommon = result === undefined;
 
-        if (isCommon) {
-          result = srcValue;
-        }
-        if ((isSrcArr || result !== undefined) &&
-            (isCommon || (result === result ? (result !== value) : (value === value)))) {
-          object[key] = result;
+          if (isCommon) {
+            result = srcValue;
+          }
+          if ((isSrcArr || result !== undefined) &&
+              (isCommon || (result === result ? (result !== value) : (value === value)))) {
+            object[key] = result;
+          }
         }
       });
       return object;
diff --git a/test/test.js b/test/test.js
index a74b09e35..3131e67cf 100644
--- a/test/test.js
+++ b/test/test.js
@@ -5767,6 +5767,25 @@
       deepEqual(func({}, new Foo), { 'a': 1 });
     });
 
+    test('`_.' + methodName + '` should assign own symbols', 2, function() {
+      if (Symbol) {
+        var symbol1 = Symbol('a'),
+            symbol2 = Symbol('b');
+
+        var Foo = function() {
+          this[symbol1] = 1;
+        };
+        Foo.prototype[symbol2] = 2;
+
+        var actual = func({}, new Foo);
+        strictEqual(actual[symbol1], 1);
+        strictEqual(actual[symbol2], undefined);
+      }
+      else {
+        skipTest(2);
+      }
+    });
+
     test('`_.' + methodName + '` should assign problem JScript properties (test in IE < 9)', 1, function() {
       var object = {
         'constructor': '0',
@@ -5881,7 +5900,7 @@
       if (isMerge) {
         expected.push([undefined, 2, 'b', sourceValue, sourceValue]);
       }
-      deepEqual(argsList, expected, 'non-primitive property values');
+      deepEqual(argsList, expected, 'object property values');
     });
 
     test('`_.' + methodName + '` should support the `thisArg` argument', 1, function() {