jquery fx: closes #3495. Animations are synchronous when duration is 0.

diff --git a/src/fx.js b/src/fx.js
index 9dcedbf..8cb7b99 100644 (file)
--- a/src/fx.js
+++ b/src/fx.js
@@ -208,9 +208,8 @@ jQuery.extend({
                        easing: fn && easing || easing && easing.constructor != Function && easing
                };
 
-               opt.duration = (opt.duration && opt.duration.constructor == Number ?
-                       opt.duration :
-                       jQuery.fx.speeds[opt.duration]) || jQuery.fx.speeds._default;
+               opt.duration = typeof opt.duration == 'number' ? opt.duration :
+                       jQuery.fx.speeds[opt.duration] || jQuery.fx.speeds._default;
 
                // Queueing
                opt.old = opt.complete;
@@ -278,7 +277,6 @@ jQuery.fx.prototype = {
                this.unit = unit || this.unit || "px";
                this.now = this.start;
                this.pos = this.state = 0;
-               this.update();
 
                var self = this;
                function t(gotoEnd){
@@ -289,7 +287,7 @@ jQuery.fx.prototype = {
 
                jQuery.timers.push(t);
 
-               if ( jQuery.timerId == null ) {
+               if ( t() && jQuery.timerId == null ) {
                        jQuery.timerId = setInterval(function(){
                                var timers = jQuery.timers;
 
@@ -337,7 +335,7 @@ jQuery.fx.prototype = {
        step: function(gotoEnd){
                var t = now();
 
-               if ( gotoEnd || t > this.options.duration + this.startTime ) {
+               if ( gotoEnd || t >= this.options.duration + this.startTime ) {
                        this.now = this.end;
                        this.pos = this.state = 1;
                        this.update();