Refactor queueing system to allow auto-dequeuing to use dequeue directly and

therefore require dequeue to always leave the element it has dequeued on
the queue.

  - In the fx queue, a progress sentinel is added when a queue element
    is dequeued.
  - The sentinel is ignored when dequeue is called explicitly
  - When adding a new element to the fx queue, queue() checks if
    the progress sentinel is present. If not, it calls dequeue()

src/data.js

@@ -63,30 +63,37 @@ jQuery.extend({
 		}
 	},
 	queue: function( elem, type, data ) {
-		if ( elem ){
+		if( !elem ) return;
 
 		type = (type || "fx") + "queue";
-
 		var q = jQuery.data( elem, type );
 
+		// Speed up dequeue by getting out quickly if this is just a lookup
+		if( !data ) return q || [];
+
 		if ( !q || jQuery.isArray(data) )
 			q = jQuery.data( elem, type, jQuery.makeArray(data) );
-			else if( data )
+		else
 			q.push( data );
 
-		}
 		return q;
 	},
 
 	dequeue: function( elem, type ){
-		var queue = jQuery.queue( elem, type ),
-			fn = queue.shift();
+		type = type || "fx";
 
-		if( !type || type === "fx" )
-			fn = queue[0];
+		var queue = jQuery.queue( elem, type ), fn = queue.shift();
 
-		if( fn !== undefined )
-			fn.call(elem, function() { jQuery(elem).dequeue(type); });
+		// If the fx queue is dequeued, always remove the progress sentinel
+		if( fn === "inprogress" ) fn = queue.shift();
+
+		if( fn ) {
+			// Add a progress sentinel to prevent the fx queue from being
+			// automatically dequeued
+			if( type == "fx" ) queue.unshift("inprogress");
+
+			fn.call(elem, function() { jQuery.dequeue(elem, type); });
+		}
 	}
 });
 
@@ -129,8 +136,8 @@ jQuery.fn.extend({
 		return this.each(function(i, elem){
 			var queue = jQuery.queue( this, type, data );
 
-			if( type == "fx" && queue.length == 1 )
-				queue[0].call(this, function() { jQuery(elem).dequeue(type); });
+			if( type == "fx" && queue[0] !== "inprogress" )
+				jQuery.dequeue( this, type )
 		});
 	},
 	dequeue: function(type){

test/unit/data.js

@@ -113,20 +113,23 @@ test(".removeData()", function() {
 });
 
 test("queue() defaults to 'fx' type", function () {
-	expect(2);
+	expect(1);
 	stop();
 
-	var $foo = jQuery("#foo");
-	$foo.queue("fx", [ "sample", "array" ]);
-	var arr = $foo.queue();
-	isSet(arr, [ "sample", "array" ], "queue() got an array set with type 'fx'");
-	$foo.queue([ "another", "one" ]);
-	var arr = $foo.queue("fx");
-	isSet(arr, [ "another", "one" ], "queue('fx') got an array set with no type");
-	// clean up after test
-	$foo.queue([]);
+	var counter = 0;
 
+	var $foo = jQuery("#foo");
+
+	$foo.queue(function() {
+		var self = this;
+		setTimeout(function() {
+			jQuery(self).dequeue("fx");
 			start();
+		}, 200);
+	}).queue(function() {
+		ok( "dequeuing 'fx' calls queues created with no name" )
+	});
+
 });
 
 test("queue() with other types",function() {
@@ -162,9 +165,6 @@ test("queue() with other types",function() {
 	
 	equals( counter, 4, "Testing previous call to dequeue" );
 	equals( $div.queue('foo').length, 0, "Testing queue length" );
-	
-	// Clean up
-	$div.removeData();
 });
 
 test("queue(name) passes in the next item in the queue as a parameter", function() {
@@ -184,8 +184,6 @@ test("queue(name) passes in the next item in the queue as a parameter", function
 	});
 	
 	div.dequeue("foo");
-	
-	div.removeData();
 });
 
 test("queue(name) passes in the next item in the queue as a parameter", function() {
@@ -205,27 +203,27 @@ test("queue(name) passes in the next item in the queue as a parameter", function
 	});
 	
 	div.dequeue("foo");
-	
-	div.removeData();
 });
 
 test("queue() passes in the next item in the queue as a parameter to fx queues", function() {
 	expect(2);
+	stop();
 	
 	var div = jQuery({});
 	var counter = 0;
 	
 	div.queue(function(next) {
 		equals(++counter, 1, "Dequeueing");
-		next();
+		var self = this;
+		setTimeout(function() { next() }, 500);
 	}).queue(function(next) {
 		equals(++counter, 2, "Next was called");
 		next();
+		start();
 	}).queue("bar", function() {
 		equals(++counter, 3, "Other queues are not triggered by next()")
 	});
 
-	div.removeData();
 });
 
 test("clearQueue(name) clears the queue", function() {
@@ -245,8 +243,6 @@ test("clearQueue(name) clears the queue", function() {
 	div.dequeue("foo");
 	
 	equals(counter, 1, "the queue was cleared");
-	
-	div.removeData();
 });
 
 test("clearQueue() clears the fx queue", function() {
@@ -257,7 +253,8 @@ test("clearQueue() clears the fx queue", function() {
 	
 	div.queue(function(next) {
 		counter++;
-		setTimeout(function() { jQuery(this).clearQueue(); next(); }, 50);
+		var self = this;
+		setTimeout(function() { jQuery(self).clearQueue(); next(); }, 50);
 	}).queue(function(next) {
 		counter++;
 	});