Ref #8908. Update IE9 css clone fix. Close gh-1119.

src/css.js

@@ -216,18 +216,13 @@ jQuery.extend({
 
 			// Fixes #8908, it can be done more correctly by specifing setters in cssHooks,
 			// but it would mean to define eight (for every problematic property) identical functions
-			if ( value === "" && name.indexOf("background") === 0 ) {
-				value = " ";
+			if ( !jQuery.support.clearCloneStyle && value === "" && name.indexOf("background") === 0 ) {
+				style[ name ] = "inherit";
 			}
 
 			// If a hook was provided, use that value, otherwise just set the specified value
 			if ( !hooks || !("set" in hooks) || (value = hooks.set( elem, value, extra )) !== undefined ) {
-
-				// Wrapped to prevent IE from throwing errors when 'invalid' values are provided
-				// Fixes bug #5509
-				try {
-					style[ name ] = value;
-				} catch(e) {}
+				style[ name ] = value;
 			}
 
 		} else {

src/support.js

@@ -64,6 +64,10 @@ jQuery.support = (function() {
 	div.setAttribute( "onfocusin", "t" );
 	support.focusinBubbles = "onfocusin" in window || div.attributes.onfocusin.expando === false;
 
+	div.style.backgroundClip = "content-box";
+	div.cloneNode().style.backgroundClip = "";
+	support.clearCloneStyle = div.style.backgroundClip === "content-box";
+
 	// Run tests that need a body at doc ready
 	jQuery(function() {
 		var container, marginDiv, tds,

test/unit/css.js

@@ -883,7 +883,7 @@ test( "css opacity consistency across browsers (#12685)", function() {
 		equal( Math.round( el.css("opacity") * 100 ), 20, "remove opacity override" );
 });
 
-asyncTest( "Clearing a Cloned Element's Style Shouldn't Clear the Original Element's Style (#8908)", 16, function() {
+asyncTest( "Clearing a Cloned Element's Style Shouldn't Clear the Original Element's Style (#8908)", 24, function() {
 	var baseUrl = document.location.href.replace( /([^\/]*)$/, "" ),
 	styles = [{
 			name: "backgroundAttachment",
@@ -921,7 +921,7 @@ asyncTest( "Clearing a Cloned Element's Style Shouldn't Clear the Original Eleme
 			expected: [ "auto auto" ]
 	}];
 
-	jQuery.each( styles, function(index, style) {
+	jQuery.each(styles, function( index, style ) {
 		var $clone, $clonedChildren,
 			$source = jQuery( "#firstp" ),
 			source = $source[ 0 ],
@@ -932,6 +932,7 @@ asyncTest( "Clearing a Cloned Element's Style Shouldn't Clear the Original Eleme
 		if ( source.style[ style.name ] === undefined ) {
 			ok( true, style.name +  ": style isn't supported and therefore not an issue" );
 			ok( true );
+
 			return true;
 		}
 
@@ -945,6 +946,8 @@ asyncTest( "Clearing a Cloned Element's Style Shouldn't Clear the Original Eleme
 		$clonedChildren.css( style.name, "" );
 
 		window.setTimeout(function() {
+			notEqual( $clone.css( style.name ), style.value[ 0 ], "Cloned css was changed" );
+
 			ok( jQuery.inArray( $source.css( style.name ) !== -1, style.value ),
 				"Clearing clone.css() doesn't affect source.css(): " + style.name +
 				"; result: " + $source.css( style.name ) +