From 56c5ebcb7190fc72d46e8ff4cbcabbeb0d1eb33d Mon Sep 17 00:00:00 2001
From: jdalton <john.david.dalton@gmail.com>
Date: Tue, 10 Mar 2015 21:31:24 -0700
Subject: [PATCH] Ensure the result of `_.difference` is based on the values of
 the first param only. [#1038]

---
 lodash.src.js | 20 +++++++-------------
 test/test.js  | 19 ++++++++++++-------
 2 files changed, 19 insertions(+), 20 deletions(-)

diff --git a/lodash.src.js b/lodash.src.js
index efc25871a..617dbb345 100644
--- a/lodash.src.js
+++ b/lodash.src.js
@@ -4363,18 +4363,10 @@
      * _.difference([1, 2, 3], [4, 2]);
      * // => [1, 3]
      */
-    function difference() {
-      var args = arguments,
-          index = -1,
-          length = args.length;
-
-      while (++index < length) {
-        var value = args[index];
-        if (isArray(value) || isArguments(value)) {
-          break;
-        }
-      }
-      return baseDifference(value, baseFlatten(args, false, true, ++index));
+    function difference(array) {
+      return (isArray(array) || isArguments(array))
+        ? baseDifference(array, baseFlatten(arguments, false, true, 1))
+        : [];
     }
 
     /**
@@ -5570,7 +5562,9 @@
      * // => [3]
      */
     function without(array) {
-      return baseDifference(array, baseSlice(arguments, 1));
+      return (isArray(array) || isArguments(array))
+        ? baseDifference(array, baseSlice(arguments, 1))
+        : [];
     }
 
     /**
diff --git a/test/test.js b/test/test.js
index b92c436bf..a833f02e4 100644
--- a/test/test.js
+++ b/test/test.js
@@ -3740,11 +3740,12 @@
       deepEqual(_.difference([1, NaN, 3], largeArray), [1, 3]);
     });
 
-    test('should ignore values that are not arrays or `arguments` objects', 3, function() {
-      var array = [0, 1, null, 3];
-      deepEqual(_.difference(array, 3, null, { '0': 1 }), array);
-      deepEqual(_.difference(null, array, null, [2, 1]), [0, null, 3]);
-      deepEqual(_.difference(array, null, args, null), [0, null]);
+    test('should ignore values that are not arrays or `arguments` objects', 4, function() {
+      var array = [1, null, 3];
+      deepEqual(_.difference(args, 3, { '0': 1 }), [1, 2, 3]);
+      deepEqual(_.difference(null, array, 1), []);
+      deepEqual(_.difference(array, args, null), [null]);
+      deepEqual(_.difference('abc', array, 'b'), []);
     });
   }(1, 2, 3));
 
@@ -15173,7 +15174,11 @@
       var array = [1, 2, 3, 1, 2, 3];
       deepEqual(_.without(array, 1, 2), [3, 3]);
     });
-  }());
+
+    test('should treat string values for `array` as empty', 1, function() {
+      deepEqual(_.without('abc', 'b'), []);
+    });
+  }(1, 2, 3));
 
   /*--------------------------------------------------------------------------*/
 
@@ -16134,7 +16139,7 @@
         return '`_.' + methodName + '` should accept falsey primary arguments';
       }
 
-      deepEqual(_.difference(null, array), array, message('difference'));
+      deepEqual(_.difference(null, array), [], message('difference'));
       deepEqual(_.intersection(null, array), array, message('intersection'));
       deepEqual(_.union(null, array), array, message('union'));
       deepEqual(_.xor(null, array), array, message('xor'));