Traversing: Fix `contents()` on `<object>`s with children

Fixes gh-4384
Closes gh-4385

2 files changed, 14 insertions, 1 deletions

diff --git a/src/traversing.js b/src/traversing.js
index 18b964a49..a91183b28 100644
--- a/src/traversing.js
+++ b/src/traversing.js
@@ -145,7 +145,7 @@ jQuery.each( {
 		return siblings( elem.firstChild );
 	},
 	contents: function( elem ) {
-		if ( typeof elem.contentDocument !== "undefined" ) {
+		if ( elem.contentDocument != null ) {
 			return elem.contentDocument;
 		}
 
diff --git a/test/unit/traversing.js b/test/unit/traversing.js
index e70c121ed..e8d23536e 100644
--- a/test/unit/traversing.js
+++ b/test/unit/traversing.js
@@ -808,6 +808,19 @@ QUnit.test( "contents() for <object />", function( assert ) {
 	jQuery( "#qunit-fixture" ).append( svgObject );
 } );
 
+QUnit.test( "contents() for <object /> with children", function( assert ) {
+	assert.expect( 1 );
+
+	var object = "<object type='application/x-shockwave-flash' width='200' height='300' id='penguin'>" +
+		"<param name='movie' value='flash/penguin.swf'>" +
+		"<param name='quality' value='high'>" +
+		"<img src='images/penguin.jpg' width='200' height='300' alt='Penguin'>" +
+	"</object>";
+
+	var contents = jQuery( object ).contents();
+	assert.equal( contents.length, 3, "Check object contents children are correct" );
+} );
+
 QUnit.test( "contents() for <frame />", function( assert ) {
 	assert.expect( 2 );