diff --git a/src/css.js b/src/css.js
index 286eef64b..7b011668e 100644
--- a/src/css.js
+++ b/src/css.js
@@ -11,16 +11,15 @@ define([
 	"./css/var/swap",
 	"./css/curCSS",
 	"./css/adjustCSS",
-	"./css/defaultDisplay",
 	"./css/addGetHookIf",
 	"./css/support",
-	"./data/var/dataPriv",
+	"./css/showHide",
 
 	"./core/init",
 	"./core/ready",
 	"./selector" // contains
 ], function( jQuery, pnum, access, rmargin, rcssNum, rnumnonpx, cssExpand, isHidden,
-	getStyles, swap, curCSS, adjustCSS, defaultDisplay, addGetHookIf, support, dataPriv ) {
+	getStyles, swap, curCSS, adjustCSS, addGetHookIf, support, showHide ) {
 
 var
 	// Swappable if display is none or starts with table
@@ -151,65 +150,6 @@ function getWidthOrHeight( elem, name, extra ) {
 	) + "px";
 }
 
-function showHide( elements, show ) {
-	var display, elem, hidden,
-		values = [],
-		index = 0,
-		length = elements.length;
-
-	for ( ; index < length; index++ ) {
-		elem = elements[ index ];
-		if ( !elem.style ) {
-			continue;
-		}
-
-		values[ index ] = dataPriv.get( elem, "olddisplay" );
-		display = elem.style.display;
-		if ( show ) {
-			// Reset the inline display of this element to learn if it is
-			// being hidden by cascaded rules or not
-			if ( !values[ index ] && display === "none" ) {
-				elem.style.display = "";
-			}
-
-			// Set elements which have been overridden with display: none
-			// in a stylesheet to whatever the default browser style is
-			// for such an element
-			if ( elem.style.display === "" && isHidden( elem ) ) {
-				values[ index ] = dataPriv.access(
-					elem,
-					"olddisplay",
-					defaultDisplay(elem.nodeName)
-				);
-			}
-		} else {
-			hidden = isHidden( elem );
-
-			if ( display !== "none" || !hidden ) {
-				dataPriv.set(
-					elem,
-					"olddisplay",
-					hidden ? display : jQuery.css( elem, "display" )
-				);
-			}
-		}
-	}
-
-	// Set the display of most of the elements in a second loop
-	// to avoid the constant reflow
-	for ( index = 0; index < length; index++ ) {
-		elem = elements[ index ];
-		if ( !elem.style ) {
-			continue;
-		}
-		if ( !show || elem.style.display === "none" || elem.style.display === "" ) {
-			elem.style.display = show ? values[ index ] || "" : "none";
-		}
-	}
-
-	return elements;
-}
-
 jQuery.extend({
 
 	// Add in style property hooks for overriding the default
diff --git a/src/css/defaultDisplay.js b/src/css/defaultDisplay.js
deleted file mode 100644
index 3771be6d1..000000000
--- a/src/css/defaultDisplay.js
+++ /dev/null
@@ -1,71 +0,0 @@
-define([
-	"../core",
-	"../var/document",
-	"../manipulation" // appendTo
-], function( jQuery, document ) {
-
-var iframe,
-	elemdisplay = {
-
-		// Support: Firefox
-		// We have to pre-define these values for FF (#10227)
-		HTML: "block",
-		BODY: "block"
-	};
-
-/**
- * Retrieve the actual display of a element
- * @param {String} name nodeName of the element
- * @param {Object} doc Document object
- */
-// Called only from within defaultDisplay
-function actualDisplay( name, doc ) {
-	var elem = jQuery( doc.createElement( name ) ).appendTo( doc.body ),
-
-		display = jQuery.css( elem[ 0 ], "display" );
-
-	// We don't have any data stored on the element,
-	// so use "detach" method as fast way to get rid of the element
-	elem.detach();
-
-	return display;
-}
-
-/**
- * Try to determine the default display value of an element
- * @param {String} nodeName
- */
-function defaultDisplay( nodeName ) {
-	var doc = document,
-		display = elemdisplay[ nodeName ];
-
-	if ( !display ) {
-		display = actualDisplay( nodeName, doc );
-
-		// If the simple way fails, read from inside an iframe
-		if ( display === "none" || !display ) {
-
-			// Use the already-created iframe if possible
-			iframe = (iframe || jQuery( "<iframe frameborder='0' width='0' height='0'/>" ))
-				.appendTo( doc.documentElement );
-
-			// Always write a new HTML skeleton so Webkit and Firefox don't choke on reuse
-			doc = iframe[ 0 ].contentDocument;
-
-			// Support: IE
-			doc.write();
-			doc.close();
-
-			display = actualDisplay( nodeName, doc );
-			iframe.detach();
-		}
-
-		// Store the correct default display
-		elemdisplay[ nodeName ] = display;
-	}
-
-	return display;
-}
-
-return defaultDisplay;
-});
diff --git a/src/css/showHide.js b/src/css/showHide.js
new file mode 100644
index 000000000..d0cca589b
--- /dev/null
+++ b/src/css/showHide.js
@@ -0,0 +1,47 @@
+define([
+	"../data/var/dataPriv"
+], function( dataPriv ) {
+
+function showHide( elements, show ) {
+	var display, elem,
+		values = [],
+		index = 0,
+		length = elements.length;
+
+	// Determine new display value for elements that need to change
+	for ( ; index < length; index++ ) {
+		elem = elements[ index ];
+		if ( !elem.style ) {
+			continue;
+		}
+
+		display = elem.style.display;
+		if ( show ) {
+			if ( display === "none" ) {
+				// Restore a pre-hide() value if we have one
+				values[ index ] = dataPriv.get( elem, "display" ) || "";
+			}
+		} else {
+			if ( display !== "none" ) {
+				values[ index ] = "none";
+
+				// Remember the value we're replacing
+				dataPriv.set( elem, "display", display );
+			}
+		}
+	}
+
+	// Set the display of the elements in a second loop
+	// to avoid the constant reflow
+	for ( index = 0; index < length; index++ ) {
+		if ( values[ index ] != null ) {
+			elements[ index ].style.display = values[ index ];
+		}
+	}
+
+	return elements;
+}
+
+return showHide;
+
+});
diff --git a/src/effects.js b/src/effects.js
index 4ead51ccd..3268fcda9 100644
--- a/src/effects.js
+++ b/src/effects.js
@@ -4,18 +4,19 @@ define([
 	"./var/rcssNum",
 	"./css/var/cssExpand",
 	"./css/var/isHidden",
+	"./css/var/swap",
 	"./css/adjustCSS",
-	"./css/defaultDisplay",
 	"./data/var/dataPriv",
+	"./css/showHide",
 
 	"./core/init",
-	"./effects/Tween",
 	"./queue",
-	"./css",
 	"./deferred",
-	"./traversing"
-], function( jQuery, document, rcssNum, cssExpand,
-	isHidden, adjustCSS, defaultDisplay, dataPriv ) {
+	"./traversing",
+	"./manipulation",
+	"./css",
+	"./effects/Tween"
+], function( jQuery, document, rcssNum, cssExpand, isHidden, swap, adjustCSS, dataPriv, showHide ) {
 
 var
 	fxNow, timerId,
@@ -82,14 +83,15 @@ function createTween( value, prop, animation ) {
 
 function defaultPrefilter( elem, props, opts ) {
 	/* jshint validthis: true */
-	var prop, value, toggle, tween, hooks, oldfire, display, checkDisplay,
+	var prop, value, toggle, hooks, oldfire, propTween, restoreDisplay, display,
+		isBox = "width" in props || "height" in props,
 		anim = this,
 		orig = {},
 		style = elem.style,
 		hidden = elem.nodeType && isHidden( elem ),
 		dataShow = dataPriv.get( elem, "fxshow" );
 
-	// Handle queue: false promises
+	// Queue-skipping animations hijack the fx hooks
 	if ( !opts.queue ) {
 		hooks = jQuery._queueHooks( elem, "fx" );
 		if ( hooks.unqueued == null ) {
@@ -114,24 +116,69 @@ function defaultPrefilter( elem, props, opts ) {
 		});
 	}
 
-	// Height/width overflow pass
-	if ( elem.nodeType === 1 && ( "height" in props || "width" in props ) ) {
-		// Make sure that nothing sneaks out
-		// Record all 3 overflow attributes because IE9-10 do not
-		// change the overflow attribute when overflowX and
-		// overflowY are set to the same value
+	// Detect show/hide animations
+	for ( prop in props ) {
+		value = props[ prop ];
+		if ( rfxtypes.test( value ) ) {
+			delete props[ prop ];
+			toggle = toggle || value === "toggle";
+			if ( value === ( hidden ? "hide" : "show" ) ) {
+
+				// Pretend to be hidden if this is a "show" and
+				// there is still data from a stopped show/hide
+				if ( value === "show" && dataShow && dataShow[ prop ] !== undefined ) {
+					hidden = true;
+
+				// Ignore all other no-op show/hide data
+				} else {
+					continue;
+				}
+			}
+			orig[ prop ] = dataShow && dataShow[ prop ] || jQuery.style( elem, prop );
+		}
+	}
+
+	// Bail out if this is a no-op like .hide().hide()
+	propTween = !jQuery.isEmptyObject( props );
+	if ( !propTween && jQuery.isEmptyObject( orig ) ) {
+		return;
+	}
+
+	// Restrict "overflow" and "display" styles during box animations
+	if ( isBox && elem.nodeType === 1 ) {
+		// Support: IE 9 - 11
+		// Record all 3 overflow attributes because IE does not infer the shorthand
+		// from identically-valued overflowX and overflowY
 		opts.overflow = [ style.overflow, style.overflowX, style.overflowY ];
 
-		// Set display property to inline-block for height/width
-		// animations on inline elements that are having width/height animated
+		// Identify a display type, preferring old show/hide data over the CSS cascade
+		restoreDisplay = dataShow && dataShow.display;
+		if ( restoreDisplay == null ) {
+			restoreDisplay = dataPriv.get( elem, "display" );
+		}
 		display = jQuery.css( elem, "display" );
+		if ( display === "none" ) {
+			display = restoreDisplay || swap( elem, { "display": "" }, function() {
+				return jQuery.css( elem, "display" );
+			} );
+		}
 
-		// Test default display if display is currently "none"
-		checkDisplay = display === "none" ?
-			dataPriv.get( elem, "olddisplay" ) || defaultDisplay( elem.nodeName ) : display;
+		// Animate inline elements as inline-block
+		if ( display === "inline" || display === "inline-block" && restoreDisplay != null ) {
+			if ( jQuery.css( elem, "float" ) === "none" ) {
 
-		if ( checkDisplay === "inline" && jQuery.css( elem, "float" ) === "none" ) {
-			style.display = "inline-block";
+				// Restore the original display value at the end of pure show/hide animations
+				if ( !propTween ) {
+					anim.done(function() {
+						style.display = restoreDisplay;
+					});
+					if ( restoreDisplay == null ) {
+						display = style.display;
+						restoreDisplay = display === "none" ? "" : display;
+					}
+				}
+				style.display = "inline-block";
+			}
 		}
 	}
 
@@ -144,73 +191,52 @@ function defaultPrefilter( elem, props, opts ) {
 		});
 	}
 
-	// show/hide pass
-	for ( prop in props ) {
-		value = props[ prop ];
-		if ( rfxtypes.exec( value ) ) {
-			delete props[ prop ];
-			toggle = toggle || value === "toggle";
-			if ( value === ( hidden ? "hide" : "show" ) ) {
+	// Implement show/hide animations
+	propTween = false;
+	for ( prop in orig ) {
 
-				// If there is dataShow left over from a stopped hide or show
-				// and we are going to proceed with show, we should pretend to be hidden
-				if ( value === "show" && dataShow && dataShow[ prop ] !== undefined ) {
-					hidden = true;
-				} else {
-					continue;
+		// General show/hide setup for this element animation
+		if ( !propTween ) {
+			if ( dataShow ) {
+				if ( "hidden" in dataShow ) {
+					hidden = dataShow.hidden;
 				}
+			} else {
+				dataShow = dataPriv.access( elem, "fxshow", { display: restoreDisplay } );
 			}
-			orig[ prop ] = dataShow && dataShow[ prop ] || jQuery.style( elem, prop );
 
-		// Any non-fx value stops us from restoring the original display value
-		} else {
-			display = undefined;
-		}
-	}
-
-	if ( !jQuery.isEmptyObject( orig ) ) {
-		if ( dataShow ) {
-			if ( "hidden" in dataShow ) {
-				hidden = dataShow.hidden;
+			// Store hidden/visible for toggle so `.stop().toggle()` "reverses"
+			if ( toggle ) {
+				dataShow.hidden = !hidden;
 			}
-		} else {
-			dataShow = dataPriv.access( elem, "fxshow", {} );
-		}
 
-		// Store state if its toggle - enables .stop().toggle() to "reverse"
-		if ( toggle ) {
-			dataShow.hidden = !hidden;
-		}
-		if ( hidden ) {
-			jQuery( elem ).show();
-		} else {
+			// Show elements before animating them
+			if ( hidden ) {
+				showHide( [ elem ], true );
+			}
+
+			/* jshint -W083 */
 			anim.done(function() {
-				jQuery( elem ).hide();
+				// The final step of a "hide" animation is actually hiding the element
+				if ( !hidden ) {
+					showHide( [ elem ] );
+				}
+				dataPriv.remove( elem, "fxshow" );
+				for ( prop in orig ) {
+					jQuery.style( elem, prop, orig[ prop ] );
+				}
 			});
 		}
-		anim.done(function() {
-			var prop;
 
-			dataPriv.remove( elem, "fxshow" );
-			for ( prop in orig ) {
-				jQuery.style( elem, prop, orig[ prop ] );
-			}
-		});
-		for ( prop in orig ) {
-			tween = createTween( hidden ? dataShow[ prop ] : 0, prop, anim );
-
-			if ( !( prop in dataShow ) ) {
-				dataShow[ prop ] = tween.start;
-				if ( hidden ) {
-					tween.end = tween.start;
-					tween.start = prop === "width" || prop === "height" ? 1 : 0;
-				}
+		// Per-property setup
+		propTween = createTween( hidden ? dataShow[ prop ] : 0, prop, anim );
+		if ( !( prop in dataShow ) ) {
+			dataShow[ prop ] = propTween.start;
+			if ( hidden ) {
+				propTween.end = propTween.start;
+				propTween.start = prop === "width" || prop === "height" ? 1 : 0;
 			}
 		}
-
-	// If this is a noop like .hide().hide(), restore an overwritten display value
-	} else if ( (display === "none" ? defaultDisplay( elem.nodeName ) : display) === "inline" ) {
-		style.display = display;
 	}
 }
 
diff --git a/test/data/testsuite.css b/test/data/testsuite.css
index cf2ba8c20..50619b98d 100644
--- a/test/data/testsuite.css
+++ b/test/data/testsuite.css
@@ -68,7 +68,8 @@ div.noopacity {
 	opacity: 0;
 }
 
-div.hidden {
+div.hidden,
+span.hidden {
 	display: none;
 }
 
@@ -116,19 +117,10 @@ div#fx-tests div.noback {
 	display: none;
 }
 
-/* tests to ensure jQuery can determine the native display mode of elements
-   that have been set as display: none in stylesheets */
-div#show-tests * { display: none; }
-
 #nothiddendiv { font-size: 16px; }
 #nothiddendivchild.em { font-size: 2em; }
 #nothiddendivchild.prct { font-size: 150%; }
 
-/* 8099 changes to default styles are read correctly */
-tt { display: none; }
-sup { display: none; }
-dfn { display: none; }
-
 /* #9239 Attach a background to the body( avoid crashes in removing the test element in support ) */
 body, div { background: url(http://static.jquery.com/files/rocker/images/logo_jquery_215x53.gif) no-repeat -1000px 0; }
 
diff --git a/test/unit/css.js b/test/unit/css.js
index 3117b12d7..b977b067c 100644
--- a/test/unit/css.js
+++ b/test/unit/css.js
@@ -475,14 +475,14 @@ test("show(); hide()", function() {
 
 	hiddendiv = jQuery("div.hidden");
 	hiddendiv.hide();
-	equal( hiddendiv.css("display"), "none", "Non-detached div hidden" );
+	equal( hiddendiv.css("display"), "none", "Cascade-hidden div after hide()" );
 	hiddendiv.show();
-	equal( hiddendiv.css("display"), "block", "Pre-hidden div shown" );
+	equal( hiddendiv.css("display"), "none", "Show does not trump CSS cascade" );
 
 	div = jQuery("<div>").hide();
 	equal( div.css("display"), "none", "Detached div hidden" );
 	div.appendTo("#qunit-fixture").show();
-	equal( div.css("display"), "block", "Pre-hidden div shown" );
+	equal( div.css("display"), "block", "Initially-detached div after show()" );
 
 });
 
@@ -490,8 +490,8 @@ test("show();", function() {
 
 	expect( 18 );
 
-  var hiddendiv, div, pass, old, test;
-	hiddendiv = jQuery("div.hidden");
+	var hiddendiv, div, pass, old, test;
+		hiddendiv = jQuery("div.hidden");
 
 	equal(jQuery.css( hiddendiv[0], "display"), "none", "hiddendiv is display: none");
 
@@ -512,8 +512,13 @@ test("show();", function() {
 	});
 	ok( pass, "Show" );
 
-	// #show-tests * is set display: none in CSS
-	jQuery("#qunit-fixture").append("<div id='show-tests'><div><p><a href='#'></a></p><code></code><pre></pre><span></span></div><table><thead><tr><th></th></tr></thead><tbody><tr><td></td></tr></tbody></table><ul><li></li></ul></div><table id='test-table'></table>");
+	jQuery(
+		"<div id='show-tests'>" +
+		"<div><p><a href='#'></a></p><code></code><pre></pre><span></span></div>" +
+		"<table><thead><tr><th></th></tr></thead><tbody><tr><td></td></tr></tbody></table>" +
+		"<ul><li></li></ul></div>" +
+		"<table id='test-table'></table>"
+	).appendTo( "#qunit-fixture" ).find( "*" ).css( "display", "none" );
 
 	old = jQuery("#test-table").show().css("display") !== "table";
 	jQuery("#test-table").remove();
@@ -545,129 +550,88 @@ test("show();", function() {
 	jQuery("<div>test</div> text <span>test</span>").hide().remove();
 });
 
-test("show() resolves correct default display #8099", function() {
-	expect(7);
-	var tt8099 = jQuery("<tt/>").appendTo("body"),
-			dfn8099 = jQuery("<dfn/>", { "html": "foo"}).appendTo("body");
-
-	equal( tt8099.css("display"), "none", "default display override for all tt" );
-	equal( tt8099.show().css("display"), "inline", "Correctly resolves display:inline" );
-
-	equal( jQuery("#foo").hide().show().css("display"), "block", "Correctly resolves display:block after hide/show" );
-
-	equal( tt8099.hide().css("display"), "none", "default display override for all tt" );
-	equal( tt8099.show().css("display"), "inline", "Correctly resolves display:inline" );
-
-	equal( dfn8099.css("display"), "none", "default display override for all dfn" );
-	equal( dfn8099.show().css("display"), "inline", "Correctly resolves display:inline" );
-
-	tt8099.remove();
-	dfn8099.remove();
-});
-
 test( "show() resolves correct default display for detached nodes", function(){
-	expect( 13 );
+	expect( 16 );
 
-	var div, span, tr, trDisplay;
+	var div, span, tr;
 
 	div = jQuery("<div class='hidden'>");
 	div.show().appendTo("#qunit-fixture");
-	equal( div.css("display"), "block", "Make sure a detached, pre-hidden( through stylesheets ) div is visible." );
-
-	div = jQuery("<div style='display: none'>");
-	div.show().appendTo("#qunit-fixture");
-	equal( div.css("display"), "block", "Make sure a detached, pre-hidden( through inline style ) div is visible." );
-
-	span = jQuery("<span class='hidden'/>");
-	span.show().appendTo("#qunit-fixture");
-	equal( span.css("display"), "inline", "Make sure a detached, pre-hidden( through stylesheets ) span has default display." );
-
-	span = jQuery("<span style='display: inline'/>");
-	span.show().appendTo("#qunit-fixture");
-	equal( span.css("display"), "inline", "Make sure a detached, pre-hidden( through inline style ) span has default display." );
+	equal( div.css("display"), "none",
+		"A shown-while-detached div can be hidden by the CSS cascade" );
 
 	div = jQuery("<div><div class='hidden'></div></div>").children("div");
 	div.show().appendTo("#qunit-fixture");
-	equal( div.css("display"), "block", "Make sure a detached, pre-hidden( through stylesheets ) div inside another visible div is visible." );
+	equal( div.css("display"), "none",
+		"A shown-while-detached div inside a visible div can be hidden by the CSS cascade" );
 
-	div = jQuery("<div><div style='display: none'></div></div>").children("div");
-	div.show().appendTo("#qunit-fixture");
-	equal( div.css("display"), "block", "Make sure a detached, pre-hidden( through inline style ) div inside another visible div is visible." );
+	span = jQuery("<span class='hidden'/>");
+	span.show().appendTo("#qunit-fixture");
+	equal( span.css("display"), "none",
+		"A shown-while-detached span can be hidden by the CSS cascade" );
 
 	div = jQuery("div.hidden");
 	div.detach().show();
-	equal( div.css("display"), "block", "Make sure a detached( through detach() ), pre-hidden div is visible." );
+	ok( !div[ 0 ].style.display,
+		"show() does not update inline style of a cascade-hidden-before-detach div" );
+	div.appendTo("#qunit-fixture");
+	equal( div.css("display"), "none",
+		"A shown-while-detached cascade-hidden div is hidden after attachment" );
 	div.remove();
 
-	span = jQuery("<span>");
-	span.appendTo("#qunit-fixture").detach().show().appendTo("#qunit-fixture" );
-	equal( span.css("display"), "inline", "Make sure a detached( through detach() ), pre-hidden span has default display." );
+	span = jQuery("<span class='hidden'/>");
+	span.appendTo("#qunit-fixture").detach().show().appendTo("#qunit-fixture");
+	equal( span.css("display"), "none",
+		"A shown-while-detached cascade-hidden span is hidden after attachment" );
 	span.remove();
 
-	div = jQuery("<div>");
-	div.show().appendTo("#qunit-fixture");
-	ok( !!div.get( 0 ).style.display, "Make sure not hidden div has a inline style." );
-	div.remove();
-
 	div = jQuery( document.createElement("div") );
 	div.show().appendTo("#qunit-fixture");
-	equal( div.css("display"), "block", "Make sure a pre-created element has default display." );
+	ok( !div[ 0 ].style.display, "A shown-while-detached div has no inline style" );
+	equal( div.css("display"), "block",
+		"A shown-while-detached div has default display after attachment" );
 	div.remove();
 
+	div = jQuery("<div style='display: none'>");
+	div.show();
+	equal( div[ 0 ].style.display, "",
+		"show() updates inline style of a detached inline-hidden div" );
+	div.appendTo("#qunit-fixture");
+	equal( div.css("display"), "block",
+		"A shown-while-detached inline-hidden div has default display after attachment" );
+
+	div = jQuery("<div><div style='display: none'></div></div>").children("div");
+	div.show().appendTo("#qunit-fixture");
+	equal( div.css("display"), "block",
+		"A shown-while-detached inline-hidden div inside a visible div has default display " +
+		"after attachment" );
+
+	span = jQuery("<span style='display: none'/>");
+	span.show();
+	equal( span[ 0 ].style.display, "",
+		"show() updates inline style of a detached inline-hidden span" );
+	span.appendTo("#qunit-fixture");
+	equal( span.css("display"), "inline",
+		"A shown-while-detached inline-hidden span has default display after attachment" );
+
 	div = jQuery("<div style='display: inline'/>");
 	div.show().appendTo("#qunit-fixture");
-	equal( div.css("display"), "inline", "Make sure that element has same display when it was created." );
+	equal( div.css("display"), "inline",
+		"show() does not update inline style of a detached inline-visible div" );
 	div.remove();
 
 	tr = jQuery("<tr/>");
 	jQuery("#table").append( tr );
-	trDisplay = tr.css( "display" );
 	tr.detach().hide().show();
 
-	equal( tr[ 0 ].style.display, trDisplay, "For detached tr elements, display should always be like for attached trs" );
+	ok( !tr[ 0 ].style.display, "Not-hidden detached tr elements have no inline style" );
 	tr.remove();
 
 	span = jQuery("<span/>").hide().show();
-	equal( span[ 0 ].style.display, "inline", "For detached span elements, display should always be inline" );
+	ok( !span[ 0 ].style.display, "Not-hidden detached span elements have no inline style" );
 	span.remove();
 });
 
-test("show() resolves correct default display #10227", 4, function() {
-	var html = jQuery( document.documentElement ),
-		body = jQuery( "body" );
-
-	body.append( "<p class='ddisplay'>a<style>body{display:none}</style></p>" );
-
-	equal( body.css("display"), "none", "Initial display for body element: none" );
-
-	body.show();
-	equal( body.css("display"), "block", "Correct display for body element: block" );
-
-	body.append( "<p class='ddisplay'>a<style>html{display:none}</style></p>" );
-
-	equal( html.css("display"), "none", "Initial display for html element: none" );
-
-	html.show();
-	equal( html.css( "display" ), "block", "Correct display for html element: block" );
-
-	jQuery( ".ddisplay" ).remove();
-});
-
-test("show() resolves correct default display when iframe display:none #12904", function() {
-	expect(2);
-
-	var ddisplay = jQuery(
-		"<p id='ddisplay'>a<style>p{display:none}iframe{display:none !important}</style></p>"
-	).appendTo("body");
-
-	equal( ddisplay.css("display"), "none", "Initial display: none" );
-
-	ddisplay.show();
-	equal( ddisplay.css("display"), "block", "Correct display: block" );
-
-	ddisplay.remove();
-});
-
 test("toggle()", function() {
 	expect(9);
 	var div, oldHide,
@@ -1094,29 +1058,6 @@ asyncTest( "Clearing a Cloned Element's Style Shouldn't Clear the Original Eleme
 	window.setTimeout( start, 1000 );
 });
 
-asyncTest( "Make sure initialized display value for disconnected nodes is correct (#13310)", 4, function() {
-	var display = jQuery("#display").css("display"),
-		div = jQuery("<div/>");
-
-	equal( div.css( "display", "inline" ).hide().show().appendTo("body").css( "display" ), "inline", "Initialized display value has returned" );
-	div.remove();
-
-	div.css( "display", "none" ).hide();
-	equal( jQuery._data( div[ 0 ], "olddisplay" ), undefined, "olddisplay is undefined after hiding a detached and hidden element" );
-	div.remove();
-
-	div.css( "display", "inline-block" ).hide().appendTo("body").fadeIn(function() {
-		equal( div.css( "display" ), "inline-block", "Initialized display value has returned" );
-		div.remove();
-
-		start();
-	});
-
-	equal( jQuery._data( jQuery("#display").css( "display", "inline" ).hide()[ 0 ], "olddisplay" ), display,
-	"display: * !Important value should used as initialized display" );
-	jQuery._removeData( jQuery("#display")[ 0 ] );
-});
-
 test( "show() after hide() should always set display to initial value (#14750)", 1, function() {
 	var div = jQuery( "<div />" ),
 		fixture = jQuery( "#qunit-fixture" );
diff --git a/test/unit/effects.js b/test/unit/effects.js
index b2b053f3b..f23342c56 100644
--- a/test/unit/effects.js
+++ b/test/unit/effects.js
@@ -30,22 +30,13 @@ test("sanity check", function() {
 	equal( jQuery("#dl:visible, #qunit-fixture:visible, #foo:visible").length, 2, "QUnit state is correct for testing effects" );
 });
 
-test("show() basic", 2, function() {
-	var div,
-		hiddendiv = jQuery("div.hidden");
-
-	hiddendiv.hide().show();
-
-	equal( hiddendiv.css("display"), "block", "Make sure a pre-hidden div is visible." );
-
-	div = jQuery("<div>").hide().appendTo("#qunit-fixture").show();
+test("show() basic", 1, function() {
+	var div = jQuery("<div>").hide().appendTo("#qunit-fixture").show();
 
 	equal( div.css("display"), "block", "Make sure pre-hidden divs show" );
 
 	// Clean up the detached node
 	div.remove();
-
-	QUnit.expectJqData( this, hiddendiv, "olddisplay" );
 });
 
 test("show()", 27, function () {
@@ -94,8 +85,13 @@ test("show()", 27, function () {
 	// Tolerate data from show()/hide()
 	QUnit.expectJqData( this, div, "olddisplay" );
 
-	// #show-tests * is set display: none in CSS
-	jQuery("#qunit-fixture").append("<div id='show-tests'><div><p><a href='#'></a></p><code></code><pre></pre><span></span></div><table><thead><tr><th></th></tr></thead><tbody><tr><td></td></tr></tbody></table><ul><li></li></ul></div><table id='test-table'></table>");
+	jQuery(
+		"<div id='show-tests'>" +
+		"<div><p><a href='#'></a></p><code></code><pre></pre><span></span></div>" +
+		"<table><thead><tr><th></th></tr></thead><tbody><tr><td></td></tr></tbody></table>" +
+		"<ul><li></li></ul></div>" +
+		"<table id='test-table'></table>"
+	).appendTo( "#qunit-fixture" ).find( "*" ).css( "display", "none" );
 
 	old = jQuery("#test-table").show().css("display") !== "table";
 	jQuery("#test-table").remove();
@@ -130,13 +126,19 @@ test("show()", 27, function () {
 });
 
 test("show(Number) - other displays", function() {
-	expect(15);
+	expect(30);
 
-	// #show-tests * is set display: none in CSS
-	jQuery("#qunit-fixture").append("<div id='show-tests'><div><p><a href='#'></a></p><code></code><pre></pre><span></span></div><table><thead><tr><th></th></tr></thead><tbody><tr><td></td></tr></tbody></table><ul><li></li></ul></div><table id='test-table'></table>");
+	jQuery(
+		"<div id='show-tests'>" +
+		"<div><p><a href='#'></a></p><code></code><pre></pre><span></span></div>" +
+		"<table><thead><tr><th></th></tr></thead><tbody><tr><td></td></tr></tbody></table>" +
+		"<ul><li></li></ul></div>" +
+		"<table id='test-table'></table>"
+	).appendTo( "#qunit-fixture" ).find( "*" ).css( "display", "none" );
 
 	var test,
 		old = jQuery("#test-table").show().css("display") !== "table";
+
 	jQuery("#test-table").remove();
 
 	// Note: inline elements are expected to be inline-block
@@ -146,10 +148,10 @@ test("show(Number) - other displays", function() {
 	test = {
 		"div"      : "block",
 		"p"        : "block",
-		"a"        : "inline-block",
-		"code"     : "inline-block",
+		"a"        : "inline",
+		"code"     : "inline",
 		"pre"      : "block",
-		"span"     : "inline-block",
+		"span"     : "inline",
 		"table"    : old ? "block" : "table",
 		"thead"    : old ? "block" : "table-header-group",
 		"tbody"    : old ? "block" : "table-row-group",
@@ -160,12 +162,26 @@ test("show(Number) - other displays", function() {
 		"li"       : old ? "block" : "list-item"
 	};
 
-	jQuery.each(test, function(selector, expected) {
-		var elem = jQuery(selector, "#show-tests").show(1, function() {
-			equal( elem.css("display"), expected, "Show using correct display type for " + selector );
+	jQuery.each( test, function( selector ) {
+		jQuery( selector, "#show-tests" ).show( 100 );
+	});
+	this.clock.tick( 50 );
+	jQuery.each( test, function( selector, expected ) {
+		jQuery( selector, "#show-tests" ).each(function() {
+			equal(
+				jQuery( this ).css( "display" ),
+				expected === "inline" ? "inline-block" : expected,
+				"Correct display type during animation for " + selector
+			);
+		});
+	});
+	this.clock.tick( 50 );
+	jQuery.each( test, function( selector, expected ) {
+		jQuery( selector, "#show-tests" ).each(function() {
+			equal( jQuery( this ).css( "display" ), expected,
+				"Correct display type after animation for " + selector );
 		});
 	});
-	this.clock.tick( 10 );
 
 	jQuery("#show-tests").remove();
 });
@@ -174,8 +190,8 @@ test("show(Number) - other displays", function() {
 test("Persist correct display value", function() {
 	expect(3);
 
-	// #show-tests * is set display: none in CSS
-	jQuery("#qunit-fixture").append("<div id='show-tests'><span style='position:absolute;'>foo</span></div>");
+	jQuery( "<div id='show-tests'><span style='position:absolute;'>foo</span></div>" )
+		.appendTo( "#qunit-fixture" ).find( "*" ).css( "display", "none" );
 
 	var $span = jQuery("#show-tests span"),
 		displayNone = $span.css("display"),
@@ -877,7 +893,7 @@ jQuery.each({
 }, function( fn, f ) {
 	jQuery.each({
 		"show": function( elem, prop ) {
-			jQuery( elem ).hide( ).addClass( "wide" + prop );
+			jQuery( elem ).hide().addClass( "wide" + prop );
 			return "show";
 		},
 		"hide": function( elem, prop ) {
@@ -912,15 +928,15 @@ jQuery.each({
 
 			num = 0;
 			// TODO: uncrowd this
-			if ( t_h === "show" ) {num++;}
-			if ( t_w === "show" ) {num++;}
-			if ( t_w === "hide" || t_w === "show" ) {num++;}
-			if ( t_h === "hide" || t_h === "show" ) {num++;}
-			if ( t_o === "hide" || t_o === "show" ) {num++;}
-			if ( t_w === "hide" ) {num++;}
-			if ( t_o.constructor === Number ) {num += 2;}
-			if ( t_w.constructor === Number ) {num += 2;}
-			if ( t_h.constructor === Number ) {num +=2;}
+			if ( t_h === "show" ) { num++; }
+			if ( t_w === "show" ) { num++; }
+			if ( t_w === "hide" || t_w === "show" ) { num++; }
+			if ( t_h === "hide" || t_h === "show" ) { num++; }
+			if ( t_o === "hide" || t_o === "show" ) { num++; }
+			if ( t_w === "hide" ) { num++; }
+			if ( t_o.constructor === Number ) { num += 2; }
+			if ( t_w.constructor === Number ) { num += 2; }
+			if ( t_h.constructor === Number ) { num += 2; }
 
 			expect( num );
 
@@ -928,13 +944,13 @@ jQuery.each({
 
 			elem.animate(anim, 50);
 
-			jQuery.when( elem ).done(function( elem ) {
-				var cur_o, cur_w, cur_h, old_h;
-
-				elem = elem[ 0 ];
+			jQuery.when( elem ).done(function( $elem ) {
+				var cur_o, cur_w, cur_h, old_h,
+					elem = $elem[ 0 ];
 
 				if ( t_w === "show" ) {
-					equal( elem.style.display, "block", "Showing, display should block: " + elem.style.display );
+					equal( $elem.css( "display" ), "block",
+						"Showing, display should block: " + elem.style.display );
 				}
 
 				if ( t_w === "hide" || t_w === "show" ) {
@@ -1498,7 +1514,7 @@ test( "User supplied callback called after show when fx off (#8892)", 2, functio
 });
 
 test( "animate should set display for disconnected nodes", function() {
-	expect( 18 );
+	expect( 20 );
 
 	var env = this,
 		methods = {
@@ -1510,42 +1526,40 @@ test( "animate should set display for disconnected nodes", function() {
 			show: [ 1 ],
 			animate: [{ width: "show" }]
 		},
-		$divTest = jQuery("<div>test</div>"),
-		// parentNode = null
 		$divEmpty = jQuery("<div/>"),
+		$divTest = jQuery("<div>test</div>"),
 		$divNone = jQuery("<div style='display: none;'/>"),
 		$divInline = jQuery("<div style='display: inline;'/>"),
+		nullParentDisplay = $divEmpty.css("display"),
+		underFragmentDisplay = $divTest.css("display"),
 		clock = this.clock;
 
-	strictEqual( $divTest.show()[ 0 ].style.display, "block", "set display with show() for element with parentNode = document fragment" );
-	strictEqual( $divEmpty.show()[ 0 ].style.display, "block", "set display with show() for element with parentNode = null" );
-	strictEqual( $divNone.show()[ 0 ].style.display, "block", "show() should change display if it already set to none" );
-	strictEqual( $divInline.show()[ 0 ].style.display, "inline", "show() should not change display if it already set" );
+	strictEqual( $divEmpty[ 0 ].parentNode, null, "Setup: element with null parentNode" );
+	strictEqual( ($divTest[ 0 ].parentNode || {}).nodeType, 11, "Setup: element under fragment" );
+
+	strictEqual( $divEmpty.show()[ 0 ].style.display, "",
+		"set display with show() for element with null parentNode" );
+	strictEqual( $divTest.show()[ 0 ].style.display, "",
+		"set display with show() for element under fragment" );
+	strictEqual( $divNone.show()[ 0 ].style.display, "",
+		"show() should change display if it already set to none" );
+	strictEqual( $divInline.show()[ 0 ].style.display, "inline",
+		"show() should not change display if it already set" );
 
-	QUnit.expectJqData( env, $divTest[ 0 ], "olddisplay" );
-	QUnit.expectJqData( env, $divEmpty[ 0 ], "olddisplay" );
 	QUnit.expectJqData( env, $divNone[ 0 ], "olddisplay" );
 
 	jQuery.each( methods, function( name, opt ) {
-		jQuery.each([
+		jQuery.fn[ name ].apply( jQuery("<div/>"), opt.concat( [ function() {
+			strictEqual( jQuery( this ).css( "display" ), nullParentDisplay,
+				"." + name + " block with null parentNode" );
+		} ] ) );
 
-			// parentNode = document fragment
-			jQuery("<div>test</div>"),
-
-			// parentNode = null
-			jQuery("<div/>")
-
-		], function() {
-			var callback = [function () {
-					strictEqual( this.style.display, "block", "set display to block with " + name );
-
-					QUnit.expectJqData( env, this, "olddisplay" );
-
-			}];
-			jQuery.fn[ name ].apply( this, opt.concat( callback ) );
-		});
+		jQuery.fn[ name ].apply( jQuery("<div>test</div>"), opt.concat( [ function() {
+			strictEqual( jQuery( this ).css( "display" ), underFragmentDisplay,
+				"." + name + " block under fragment" );
+		} ] ) );
 	});
-        clock.tick( 400 );
+	clock.tick( 400 );
 });
 
 test("Animation callback should not show animated element as :animated (#7157)", 1, function() {
@@ -2185,33 +2199,6 @@ test( "Respect display value on inline elements (#14824)", 2, function() {
 	clock.tick( 800 );
 });
 
-test( "Animation should go to its end state if document.hidden = true", 1, function() {
-	var height;
-	if ( Object.defineProperty ) {
-
-		// Can't rewrite document.hidden property if its host property
-		try {
-			Object.defineProperty( document, "hidden", {
-				get: function() {
-					return true;
-				}
-			});
-		} catch ( e ) {}
-	} else {
-		document.hidden = true;
-	}
-
-	if ( document.hidden ) {
-		height = jQuery( "#qunit-fixture" ).animate({ height: 500 } ).height();
-
-		equal( height, 500, "Animation should happen immediately if document.hidden = true" );
-		jQuery( document ).removeProp( "hidden" );
-
-	} else {
-		ok( true, "Can't run the test since we can't reproduce correct environment for it" );
-	}
-});
-
 test( "jQuery.easing._default (gh-2218)", function() {
 	expect( 2 );
 
@@ -2288,4 +2275,92 @@ test( "jQuery.easing._default in Tween (gh-2218)", function() {
 	delete jQuery.easing.custom;
 });
 
+test( "Display value is correct for disconnected nodes (trac-13310)", function() {
+	expect( 3 );
+
+	var div = jQuery("<div/>");
+
+	equal( div.css( "display", "inline" ).hide().show().appendTo("body").css( "display" ), "inline", "Initialized display value has returned" );
+	div.remove();
+
+	div.css( "display", "none" ).hide();
+	equal( jQuery._data( div[ 0 ], "olddisplay" ), undefined, "olddisplay is undefined after hiding a detached and hidden element" );
+	div.remove();
+
+	div.css( "display", "inline-block" ).hide().appendTo("body").fadeIn(function() {
+		equal( div.css( "display" ), "inline-block", "Initialized display value has returned" );
+		div.remove();
+	});
+	this.clock.tick( 1000 );
+});
+
+test( "Show/hide/toggle and display: inline", function() {
+	expect( 40 );
+
+	var clock = this.clock;
+
+	jQuery( "<span/><div style='display:inline' title='inline div'/>" ).each(function() {
+		var completed, interrupted,
+			N = 100,
+			fixture = jQuery( "#qunit-fixture" ),
+			$el = jQuery( this ),
+			kind = this.title || this.nodeName.toLowerCase();
+
+		// Animations allowed to complete
+		completed = jQuery.map( [
+			$el.clone().data({ call: "hide", done: "none" }).appendTo( fixture ).hide( N ),
+			$el.clone().data({ call: "toggle", done: "none" }).appendTo( fixture ).toggle( N ),
+			$el.clone().data({ call: "hide+show", done: "inline" }).appendTo( fixture )
+				.hide().show( N ),
+			$el.clone().data({ call: "hide+toggle", done: "inline" }).appendTo( fixture )
+				.hide().toggle( N )
+		], function( $clone ) { return $clone[ 0 ]; } );
+
+		// Animations not allowed to complete
+		interrupted = jQuery.map( [
+			$el.clone().data({ call: "hide+stop" }).appendTo( fixture ).hide( N ),
+			$el.clone().data({ call: "toggle+stop" }).appendTo( fixture ).toggle( N ),
+			$el.clone().data({ call: "hide+show+stop" }).appendTo( fixture ).hide().show( N ),
+			$el.clone().data({ call: "hide+toggle+stop" }).appendTo( fixture ).hide().toggle( N )
+		], function( $clone ) { return $clone[ 0 ]; } );
+
+		// All elements should be inline-block during the animation
+		clock.tick( N / 2 );
+		jQuery( completed ).each(function() {
+			var $el = jQuery( this ),
+				call = $el.data( "call" );
+			strictEqual( $el.css( "display" ), "inline-block", kind + " display during " + call );
+		});
+
+		// Interrupted elements should remain inline-block
+		jQuery( interrupted ).stop();
+		clock.tick( N / 2 );
+		jQuery( interrupted ).each(function() {
+			var $el = jQuery( this ),
+				call = $el.data( "call" );
+			strictEqual( $el.css( "display" ), "inline-block", kind + " display after " + call );
+		});
+
+		// Completed elements should not remain inline-block
+		clock.tick( N / 2 );
+		jQuery( completed ).each(function() {
+			var $el = jQuery( this ),
+				call = $el.data( "call" ),
+				display = $el.data( "done" );
+			strictEqual( $el.css( "display" ), display, kind + " display after " + call );
+		});
+
+		// A post-animation toggle should not make any element inline-block
+		completed = jQuery( completed.concat( interrupted ) );
+		completed.toggle( N / 2 );
+		clock.tick( N );
+		completed.each(function() {
+			var $el = jQuery( this ),
+				call = $el.data( "call" );
+			ok( $el.css( "display" ) !== "inline-block",
+				kind + " display is not inline-block after " + call + "+toggle" );
+		});
+	});
+});
+
 })();