Animation state is tracked on toggled/stopped animations using the private data cache. Tests added. Fixes #8685.

- Example: http://jsfiddle.net/timmywil/gqZL5/17/

- http://bugs.jquery.com/ticket/8685

src/effects.js

@@ -141,7 +141,8 @@ jQuery.fn.extend({
 				isElement = this.nodeType === 1,
 				hidden = isElement && jQuery(this).is(":hidden"),
 				name, val, p, e,
-				parts, start, end, unit;
+				parts, start, end, unit,
+				method;
 
 			// will store per property easing and be used to determine when an animation is complete
 			opt.animatedProperties = {};
@@ -203,7 +204,15 @@ jQuery.fn.extend({
 				val = prop[ p ];
 
 				if ( rfxtypes.test( val ) ) {
-					e[ val === "toggle" ? hidden ? "show" : "hide" : val ]();
+					// Tracks whether to show or hide based on private
+					// data attached to the element
+					method = jQuery._data( this, "toggle" + p ) || (val === "toggle" ? hidden ? "show" : "hide" : 0);
+					if ( method ) {
+						jQuery._data( this, "toggle" + p, method === "show" ? "hide" : "show" );
+						e[ method ]();
+					} else {
+						e[ val ]();
+					}
 
 				} else {
 					parts = rfxnum.exec( val );
@@ -246,6 +255,7 @@ jQuery.fn.extend({
 		this.each(function() {
 			var timers = jQuery.timers,
 				i = timers.length;
+
 			// clear marker counters if we know they won't be
 			if ( !gotoEnd ) {
 				jQuery._unmark( true, this );
@@ -255,6 +265,8 @@ jQuery.fn.extend({
 					if ( gotoEnd ) {
 						// force the next step to be the last
 						timers[ i ]( true );
+					} else {
+						timers[ i ].saveState();
 					}
 
 					timers.splice(i, 1);
@@ -398,6 +410,11 @@ jQuery.fx.prototype = {
 		}
 
 		t.elem = this.elem;
+		t.saveState = function() {
+			if ( self.options.hide && jQuery._data( self.elem, "fxshow" + self.prop ) === undefined ) {
+				jQuery._data( self.elem, "fxshow" + self.prop, self.start );
+			}
+		};
 
 		if ( t() && jQuery.timers.push(t) && !timerId ) {
 			// Use requestAnimationFrame instead of setInterval if available
@@ -419,14 +436,20 @@ jQuery.fx.prototype = {
 
 	// Simple 'show' function
 	show: function() {
+		var dataShow = jQuery._data( this.elem, "fxshow" + this.prop );
+
 		// Remember where we started, so that we can go back to it later
-		this.options.orig[ this.prop ] = jQuery.style( this.elem, this.prop );
+		this.options.orig[ this.prop ] = dataShow || jQuery.style( this.elem, this.prop );
 		this.options.show = true;
 
 		// Begin the animation
-		// Make sure that we start at a small width/height to avoid any
+		// Make sure that we start at a small width/height to avoid any flash of content
-		// flash of content
+		if ( dataShow !== undefined ) {
+			// This show is picking up where a previous hide or show left off
+			this.custom( this.cur(), dataShow );
+		} else {
 			this.custom( this.prop === "width" || this.prop === "height" ? 1 : 0, this.cur() );
+		}
 
 		// Start by showing the element
 		jQuery( this.elem ).show();
@@ -435,7 +458,7 @@ jQuery.fx.prototype = {
 	// Simple 'hide' function
 	hide: function() {
 		// Remember where we started, so that we can go back to it later
-		this.options.orig[ this.prop ] = jQuery.style( this.elem, this.prop );
+		this.options.orig[ this.prop ] = jQuery._data( this.elem, "fxshow" + this.prop ) || jQuery.style( this.elem, this.prop );
 		this.options.hide = true;
 
 		// Begin the animation
@@ -448,7 +471,7 @@ jQuery.fx.prototype = {
 			done = true,
 			elem = this.elem,
 			options = this.options,
-			i, n;
+			p, n;
 
 		if ( gotoEnd || t >= options.duration + this.startTime ) {
 			this.now = this.end;
@@ -457,8 +480,8 @@ jQuery.fx.prototype = {
 
 			options.animatedProperties[ this.prop ] = true;
 
-			for ( i in options.animatedProperties ) {
+			for ( p in options.animatedProperties ) {
-				if ( options.animatedProperties[ i ] !== true ) {
+				if ( options.animatedProperties[ p ] !== true ) {
 					done = false;
 				}
 			}
@@ -479,8 +502,11 @@ jQuery.fx.prototype = {
 
 				// Reset the properties, if the item has been hidden or shown
 				if ( options.hide || options.show ) {
-					for ( var p in options.animatedProperties ) {
+					for ( p in options.animatedProperties ) {
 						jQuery.style( elem, p, options.orig[ p ] );
+						jQuery.removeData( elem, "fxshow" + p, true );
+						// Toggle data is no longer needed
+						jQuery.removeData( elem, "toggle" + p, true );
 					}
 				}
 
@@ -512,7 +538,7 @@ jQuery.fx.prototype = {
 
 jQuery.extend( jQuery.fx, {
 	tick: function() {
-		for ( var timers = jQuery.timers, i = 0 ; i < timers.length ; ++i ) {
+		for ( var timers = jQuery.timers, i = 0; i < timers.length; i++ ) {
 			if ( !timers[ i ]() ) {
 				timers.splice(i--, 1);
 			}

test/unit/effects.js

@@ -676,23 +676,23 @@ jQuery.each( {
 		return "";
 	},
 	"JS 100": function( elem, prop ) {
-		jQuery(elem).css(prop,prop == "opacity" ? 1 : "100px");
+		jQuery( elem ).css( prop, prop === "opacity" ? 1 : "100px" );
-		return prop == "opacity" ? 1 : 100;
+		return prop === "opacity" ? 1 : 100;
 	},
 	"CSS 50": function( elem, prop ) {
 		jQuery( elem ).addClass( "med" + prop );
 		return "";
 	},
 	"JS 50": function( elem, prop ) {
-		jQuery(elem).css(prop,prop == "opacity" ? 0.50 : "50px");
+		jQuery( elem ).css( prop, prop === "opacity" ? 0.50 : "50px" );
-		return prop == "opacity" ? 0.5 : 50;
+		return prop === "opacity" ? 0.5 : 50;
 	},
 	"CSS 0": function( elem, prop ) {
 		jQuery( elem ).addClass( "no" + prop );
 		return "";
 	},
 	"JS 0": function( elem, prop ) {
-		jQuery(elem).css(prop,prop == "opacity" ? 0 : "0px");
+		jQuery( elem ).css( prop, prop === "opacity" ? 0 : "0px" );
 		return 0;
 	}
 }, function( fn, f ) {
@@ -750,22 +750,27 @@ jQuery.each( {
 
 				elem = elem[ 0 ];
 
-				if ( t_w == "show" )
+				if ( t_w == "show" ) {
 					equals( elem.style.display, "block", "Showing, display should block: " + elem.style.display );
+				}
 
-				if ( t_w == "hide"||t_w == "show" )
+				if ( t_w == "hide" || t_w == "show" ) {
 					ok( f_w === "" ? elem.style.width === f_w : elem.style.width.indexOf( f_w ) === 0, "Width must be reset to " + f_w + ": " + elem.style.width );
+				}
 
-				if ( t_h == "hide"||t_h == "show" )
+				if ( t_h == "hide" || t_h == "show" ) {
 					ok( f_h === "" ? elem.style.height === f_h : elem.style.height.indexOf( f_h ) === 0, "Height must be reset to " + f_h + ": " + elem.style.height );
+				}
 
 				var cur_o = jQuery.style(elem, "opacity");
 
-				if ( t_o == "hide" || t_o == "show" )
+				if ( t_o == "hide" || t_o == "show" ) {
 					equals( cur_o, f_o, "Opacity must be reset to " + f_o + ": " + cur_o );
+				}
 
-				if ( t_w == "hide" )
+				if ( t_w == "hide" ) {
 					equals( elem.style.display, "none", "Hiding, display should be none: " + elem.style.display );
+				}
 
 				if ( t_o.constructor == Number ) {
 					equals( cur_o, t_o, "Final opacity should be " + t_o + ": " + cur_o );
@@ -921,6 +926,42 @@ test("jQuery.show('fast') doesn't clear radio buttons (bug #1095)", function ()
 	});
 });
 
+jQuery.each({
+	"slideToggle": function( $elem ) {
+		return $elem.height();
+	},
+	"fadeToggle": function( $elem ) {
+		return $elem.css("opacity");
+	},
+	"toggle": function( $elem ) {
+		return $elem.width();
+	}
+},
+function( method, defProp ) {
+	test( method + "().stop()." + method + "()", function() {
+		expect( 4 );
+
+		jQuery.each([ "in", "out" ], function( i, type ) {
+			var $elem = jQuery( "#" + method.toLowerCase() + type ),
+				startVal = defProp( $elem );
+
+			$elem[ method ]("fast");
+			stop();
+
+			setTimeout( function() {
+				$elem.stop();
+
+				notEqual( defProp( $elem ), startVal, ".stop() is called about halfway through animation." );
+
+				$elem[ method ]("fast", function() {
+					equal( defProp( jQuery(this) ), startVal, "After doing .stop() halfway, check that state has been saved for returning to original property value." );
+					start();
+				});
+			}, 100);
+		});
+	});
+});
+
 test("animate with per-property easing", function(){
 
 	expect(5);