Merge pull request #13306 from twbs/fat-11099

fixes #11099 - $.collapse() overrides the original dimension of the coll...

diff --cc js/collapse.js
index 42563c08e73f06f1e671d22468a823d5e5fb82bf,235b1a9e6127fc93b0ccfbdd347f78efeef16176..266f3580d92eb975b5274ec4bfe12bc620c45497
--- 1/js/collapse.js
--- 2/js/collapse.js
+++ b/js/collapse.js
@@@ -56,14 -56,10 +56,14 @@@
      this.transitioning = 1
  
      var complete = function (e) {
 -      if (e && e.target != this.$element[0]) return
 +      if (e && e.target != this.$element[0]) {
 +        this.$element
 +          .one($.support.transition.end, $.proxy(complete, this))
 +        return
 +      }
        this.$element
          .removeClass('collapsing')
-         .addClass('collapse in')[dimension]('auto')
+         .addClass('collapse in')[dimension]('')
        this.transitioning = 0
        this.$element.trigger('shown.bs.collapse')
      }