Don't swap to measure dimensions unless the element is display:none. #…

…807 Fixes #11293

src/css.js

@@ -480,7 +480,7 @@ jQuery.each([ "height", "width" ], function( i, name ) {
	jQuery.cssHooks[ name ] = {
		get: function( elem, computed, extra ) {
			if ( computed ) {
				if ( elem.offsetWidth !== 0 ) {
				if ( elem.offsetWidth !== 0 || curCSS( elem, "display" ) !== "none" ) {
					return getWidthOrHeight( elem, name, extra );
				} else {
					return jQuery.swap( elem, cssShow, function() {

test/unit/dimensions.js

@@ -299,6 +299,16 @@ test("outerWidth(true) returning % instead of px in Webkit, see #10639", functio
	equal( el.outerWidth(true), 400, "outerWidth(true) and css('margin') returning % instead of px in Webkit, see #10639" );
});

test( "getting dimensions of zero width/height table elements shouldn't alter dimensions", function() {
	expect( 1 );

	var table = jQuery("<table><tbody><tr><td></td><td>a</td></tr><tr><td></td><td>a</td></tr></tbody></table>").appendTo("#qunit-fixture"),
		elem = table.find("tr:eq(0) td:eq(0)");

	table.find("td").css({ margin: 0, padding: 0 });
	equal( elem.width(), elem.width(), "width() doesn't alter dimension values" );
});

test("box-sizing:border-box child of a hidden elem (or unconnected node) has accurate inner/outer/Width()/Height()  see #10413", function() {
	expect(16);