Make sure to do a deep copy on arrays. #5750

diff --git a/src/core.js b/src/core.js
index 975d23c..58cbbc7 100644 (file)
--- a/src/core.js
+++ b/src/core.js
@@ -316,10 +316,10 @@ jQuery.extend = jQuery.fn.extend = function() {
                                        continue;
                                }
 
-                               // Recurse if we're merging object literal values
-                               if ( deep && copy && jQuery.isPlainObject(copy) ) {
-                                       // Don't extend not object literals
-                                       var clone = src && jQuery.isPlainObject(src) ? src : {};
+                               // Recurse if we're merging object literal values or arrays
+                               if ( deep && copy && ( jQuery.isPlainObject(copy) || jQuery.isArray(copy) ) ) {
+                                       var clone = src && ( jQuery.isPlainObject(src) || jQuery.isArray(src) ) ? src
+                                               : jQuery.isArray(copy) ? [] : {};
 
                                        // Never move original objects, clone them
                                        target[ name ] = jQuery.extend( deep, clone, copy );

diff --git a/test/unit/core.js b/test/unit/core.js
index d50997b..990926d 100644 (file)
--- a/test/unit/core.js
+++ b/test/unit/core.js
@@ -643,7 +643,7 @@ test("jQuery.merge()", function() {
 });
 
 test("jQuery.extend(Object, Object)", function() {
-       expect(25);
+       expect(27);
 
        var settings = { xnumber1: 5, xnumber2: 7, xstring1: "peter", xstring2: "pan" },
                options = { xnumber2: 1, xstring2: "x", xxx: "newstring" },
@@ -653,7 +653,9 @@ test("jQuery.extend(Object, Object)", function() {
                deep1copy = { foo: { bar: true } },
                deep2 = { foo: { baz: true }, foo2: document },
                deep2copy = { foo: { baz: true }, foo2: document },
-               deepmerged = { foo: { bar: true, baz: true }, foo2: document };
+               deepmerged = { foo: { bar: true, baz: true }, foo2: document },
+               arr = [1, 2, 3],
+               nestedarray = { arr: arr };
 
        jQuery.extend(settings, options);
        same( settings, merged, "Check if extended: settings must be extended" );
@@ -668,6 +670,9 @@ test("jQuery.extend(Object, Object)", function() {
        same( deep2.foo, deep2copy.foo, "Check if not deep2: options must not be modified" );
        equals( deep1.foo2, document, "Make sure that a deep clone was not attempted on the document" );
 
+       ok( jQuery.extend(true, [], arr) !== arr, "Deep extend of array must clone array" );
+       ok( jQuery.extend(true, {}, nestedarray).arr !== arr, "Deep extend of object must clone child array" );
+
        var empty = {};
        var optionsWithLength = { foo: { length: -1 } };
        jQuery.extend(true, empty, optionsWithLength);