Ticket #5750: deep-extend-array.patch

src/core.js

@@ -313 +313 @@
                                         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 = {};
+                                        // Only extend object literals or arrays
+                                        if ( src && ( jQuery.isPlainObject(src) || jQuery.isArray(src) ) ) {
+                                                clone = src;
+                                        // Don't clone an array with an object
+                                        } else if ( jQuery.isArray (copy) ) {
+                                                clone = [];
+                                        }
 
                                         // Never move original objects, clone them
                                         target[ name ] = jQuery.extend( deep, clone, copy );

test/unit/core.js

@@ -657 +657 @@
 });
 
 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" },
@@ -667 +667 @@
                 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" );
@@ -682 +684 @@
         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);