Bump to v4.17.5.

defaults.js

@@ -1,7 +1,13 @@
-import apply from './_apply.js';
-import assignInWith from './assignInWith.js';
 import baseRest from './_baseRest.js';
-import customDefaultsAssignIn from './_customDefaultsAssignIn.js';
+import eq from './eq.js';
+import isIterateeCall from './_isIterateeCall.js';
+import keysIn from './keysIn.js';
+
+/** Used for built-in method references. */
+var objectProto = Object.prototype;
+
+/** Used to check objects for own properties. */
+var hasOwnProperty = objectProto.hasOwnProperty;
 
 /**
  * Assigns own and inherited enumerable string keyed properties of source
@@ -24,9 +30,35 @@ import customDefaultsAssignIn from './_customDefaultsAssignIn.js';
  * _.defaults({ 'a': 1 }, { 'b': 2 }, { 'a': 3 });
  * // => { 'a': 1, 'b': 2 }
  */
-var defaults = baseRest(function(args) {
-  args.push(undefined, customDefaultsAssignIn);
-  return apply(assignInWith, undefined, args);
+var defaults = baseRest(function(object, sources) {
+  object = Object(object);
+
+  var index = -1;
+  var length = sources.length;
+  var guard = length > 2 ? sources[2] : undefined;
+
+  if (guard && isIterateeCall(sources[0], sources[1], guard)) {
+    length = 1;
+  }
+
+  while (++index < length) {
+    var source = sources[index];
+    var props = keysIn(source);
+    var propsIndex = -1;
+    var propsLength = props.length;
+
+    while (++propsIndex < propsLength) {
+      var key = props[propsIndex];
+      var value = object[key];
+
+      if (value === undefined ||
+          (eq(value, objectProto[key]) && !hasOwnProperty.call(object, key))) {
+        object[key] = source[key];
+      }
+    }
+  }
+
+  return object;
 });
 
 export default defaults;