Ref #8908. Update IE9 css clone fix. Close gh-1120.

src/css.js

@@ -213,8 +213,8 @@ 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

src/support.js

@@ -138,6 +138,10 @@ jQuery.support = (function() {
 		support[ i + "Bubbles" ] = eventName in window || div.attributes[ eventName ].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

@@ -923,7 +923,7 @@ 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",
@@ -961,7 +961,7 @@ 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 ],
@@ -972,6 +972,7 @@ 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 );
+			ok( true );
 			return true;
 		}
 
@@ -985,6 +986,8 @@ 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 ) +

test/unit/support.js

@@ -81,7 +81,8 @@ testIframeWithCallback( "box-sizing does not affect jQuery.support.shrinkWrapBlo
 			"reliableHiddenOffsets":true,
 			"ajax":true,
 			"cors":true,
-			"doesNotIncludeMarginInBodyOffset":true
+			"doesNotIncludeMarginInBodyOffset":true,
+			"clearCloneStyle": true
 		};
 	} else if ( /opera.*version\/12\.1/i.test( userAgent ) ) {
 		expected = {
@@ -114,7 +115,8 @@ testIframeWithCallback( "box-sizing does not affect jQuery.support.shrinkWrapBlo
 			"reliableHiddenOffsets":true,
 			"ajax":true,
 			"cors":true,
-			"doesNotIncludeMarginInBodyOffset":true
+			"doesNotIncludeMarginInBodyOffset":true,
+			"clearCloneStyle": true
 		};
 	} else if ( /msie 10\.0/i.test( userAgent ) ) {
 		expected = {
@@ -147,7 +149,8 @@ testIframeWithCallback( "box-sizing does not affect jQuery.support.shrinkWrapBlo
 			"reliableHiddenOffsets":true,
 			"ajax":true,
 			"cors":true,
-			"doesNotIncludeMarginInBodyOffset":true
+			"doesNotIncludeMarginInBodyOffset":true,
+			"clearCloneStyle": false
 		};
 	} else if ( /msie 9\.0/i.test( userAgent ) ) {
 		expected = {
@@ -180,7 +183,8 @@ testIframeWithCallback( "box-sizing does not affect jQuery.support.shrinkWrapBlo
 			"reliableHiddenOffsets":true,
 			"ajax":true,
 			"cors":false,
-			"doesNotIncludeMarginInBodyOffset":true
+			"doesNotIncludeMarginInBodyOffset":true,
+			"clearCloneStyle": false
 		};
 	} else if ( /msie 8\.0/i.test( userAgent ) ) {
 		expected = {
@@ -213,7 +217,8 @@ testIframeWithCallback( "box-sizing does not affect jQuery.support.shrinkWrapBlo
 			"reliableHiddenOffsets":false,
 			"ajax":true,
 			"cors":false,
-			"doesNotIncludeMarginInBodyOffset":true
+			"doesNotIncludeMarginInBodyOffset":true,
+			"clearCloneStyle": true
 		};
 	} else if ( /msie 7\.0/i.test( userAgent ) ) {
 		expected = {
@@ -246,7 +251,8 @@ testIframeWithCallback( "box-sizing does not affect jQuery.support.shrinkWrapBlo
 			"shrinkWrapBlocks": false,
 			"submitBubbles": false,
 			"tbody": false,
-			"style": false
+			"style": false,
+			"clearCloneStyle": true
 		};
 	} else if ( /msie 6\.0/i.test( userAgent ) ) {
 		expected = {
@@ -279,7 +285,8 @@ testIframeWithCallback( "box-sizing does not affect jQuery.support.shrinkWrapBlo
 			"reliableHiddenOffsets":false,
 			"ajax":true,
 			"cors":false,
-			"doesNotIncludeMarginInBodyOffset":true
+			"doesNotIncludeMarginInBodyOffset":true,
+			"clearCloneStyle": true
 		};
 	} else if ( /5\.1\.1 safari/i.test( userAgent ) ) {
 		expected = {
@@ -312,7 +319,8 @@ testIframeWithCallback( "box-sizing does not affect jQuery.support.shrinkWrapBlo
 			"reliableHiddenOffsets":true,
 			"ajax":true,
 			"cors":true,
-			"doesNotIncludeMarginInBodyOffset":true
+			"doesNotIncludeMarginInBodyOffset":true,
+			"clearCloneStyle": true
 		};
 	} else if ( /firefox/i.test( userAgent ) ) {
 		expected = {
@@ -345,13 +353,14 @@ testIframeWithCallback( "box-sizing does not affect jQuery.support.shrinkWrapBlo
 			"reliableHiddenOffsets":true,
 			"ajax":true,
 			"cors":true,
-			"doesNotIncludeMarginInBodyOffset":true
+			"doesNotIncludeMarginInBodyOffset":true,
+			"clearCloneStyle": true
 		};
 	}
 
 	if ( expected ) {
 		test("Verify that the support tests resolve as expected per browser", function() {
-			expect( 30 );
+			expect( 31 );
 
 			for ( var i in expected ) {
 				if ( jQuery.ajax || i !== "ajax" && i !== "cors" ) {