Ref #8908, gh-886. Avoid clone identity crisis in IE9/10. Close gh-1036.

src/css.js

@@ -211,6 +211,12 @@ jQuery.extend({
 				value += "px";
 			}
 
+			// 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 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 ) {
 
@@ -543,15 +549,6 @@ jQuery.each([ "height", "width" ], function( i, name ) {
 	};
 });
 
-if ( !jQuery.support.clearCloneStyle ) {
-	// #8908, this part for IE9 only; see gh-886
-	jQuery.cssHooks.backgroundPosition = {
-		set: function( elem, value ) {
-			return value === "" ? "0% 0%" : value;
-		}
-	};
-}
-
 if ( !jQuery.support.opacity ) {
 	jQuery.cssHooks.opacity = {
 		get: function( elem, computed ) {

src/manipulation.js

@@ -433,7 +433,7 @@ function cloneCopyEvent( src, dest ) {
 	}
 }
 
-function cloneFixAttributes( src, dest ) {
+function fixCloneNodeIssues( src, dest ) {
 	var nodeName, data, e;
 
 	// We do not need to do anything for non-Elements
@@ -559,12 +559,8 @@ jQuery.extend({
 			inPage = jQuery.contains( elem.ownerDocument, elem );
 
 		if ( jQuery.support.html5Clone || jQuery.isXMLDoc(elem) || !rnoshimcache.test( "<" + elem.nodeName + ">" ) ) {
-			// Break the original-clone style connection in IE9/10 (#8909)
-			if ( !jQuery.support.clearCloneStyle && elem.nodeType === 1 ) {
-				i = ( window.getComputedStyle( elem, null ) || {} ).backgroundPosition;
-			}
-
 			clone = elem.cloneNode( true );
+
 		// IE<=8 does not properly clone detached, unknown element nodes
 		} else {
 			fragmentDiv.innerHTML = elem.outerHTML;
@@ -582,7 +578,7 @@ jQuery.extend({
 			for ( i = 0; (node = srcElements[i]) != null; ++i ) {
 				// Ensure that the destination node is not null; Fixes #9587
 				if ( destElements[i] ) {
-					cloneFixAttributes( node, destElements[i] );
+					fixCloneNodeIssues( node, destElements[i] );
 				}
 			}
 		}

src/support.js

@@ -169,10 +169,6 @@ jQuery.support = (function() {
 		}
 	}
 
-	div.style.backgroundClip = "content-box";
-	div.cloneNode( true ).style.backgroundClip = "";
-	support.clearCloneStyle = div.style.backgroundClip === "content-box";
-
 	// Run tests that need a body at doc ready
 	jQuery(function() {
 		var container, div, tds, marginDiv,