carousel: correctly reset when the slide event is prevented

js/carousel.js

@@ -111,14 +111,16 @@
       $next = this.$element.find('.item')[fallback]()
     }
 
+    if ($next.hasClass('active')) return
+
+    var e = $.Event('slide.bs.carousel', { relatedTarget: $next[0], direction: direction })
+    this.$element.trigger(e)
+    if (e.isDefaultPrevented()) return
+
     this.sliding = true
 
     isCycling && this.pause()
 
-    var e = $.Event('slide.bs.carousel', { relatedTarget: $next[0], direction: direction })
-
-    if ($next.hasClass('active')) return
-
     if (this.$indicators.length) {
       this.$indicators.find('.active').removeClass('active')
       this.$element.one('slid', function () {
@@ -128,8 +130,6 @@
     }
 
     if ($.support.transition && this.$element.hasClass('slide')) {
-      this.$element.trigger(e)
-      if (e.isDefaultPrevented()) return
       $next.addClass(type)
       $next[0].offsetWidth // force reflow
       $active.addClass(direction)
@@ -143,8 +143,6 @@
         })
         .emulateTransitionEnd(600)
     } else {
-      this.$element.trigger(e)
-      if (e.isDefaultPrevented()) return
       $active.removeClass('active')
       $next.addClass('active')
       this.sliding = false