Fixed a problem with changeset [3841] where a function could no longer be .extend()-ed.

src/core.js

@@ -530,7 +530,7 @@ jQuery.extend = jQuery.fn.extend = function() {
 	}
 
 	// Handle case when target is a string or something (possible in deep copy)
-	if ( typeof target != "object" )
+	if ( typeof target != "object" && typeof target != "function" )
 		target = {};
 
 	// extend jQuery itself if only one argument is passed

test/unit/core.js

@@ -837,7 +837,7 @@ test("is(String)", function() {
 });
 
 test("$.extend(Object, Object)", function() {
-	expect(15);
+	expect(17);
 
 	var settings = { xnumber1: 5, xnumber2: 7, xstring1: "peter", xstring2: "pan" },
 		options =     { xnumber2: 1, xstring2: "x", xxx: "newstring" },
@@ -876,6 +876,14 @@ test("$.extend(Object, Object)", function() {
 	var ret = jQuery.extend(true, { foo:"bar" }, { foo:null } );
 	ok( typeof ret.foo !== 'undefined', "Make sure a null value doesn't crash with deep extend, for #1908" );
 
+	var obj = { foo:null };
+	jQuery.extend(true, obj, { foo:"notnull" } );
+	equals( obj.foo, "notnull", "Make sure a null value can be overwritten" );
+
+	function func() {}
+	jQuery.extend(func, { key: "value" } );
+	equals( func.key, "value", "Verify a function can be extended" );
+
 	var defaults = { xnumber1: 5, xnumber2: 7, xstring1: "peter", xstring2: "pan" },
 		defaultsCopy = { xnumber1: 5, xnumber2: 7, xstring1: "peter", xstring2: "pan" },
 		options1 =     { xnumber2: 1, xstring2: "x" },