G R U N T

dist/js/bootstrap.js

@@ -1282,7 +1282,7 @@ if (typeof jQuery === 'undefined') { throw new Error('Bootstrap\'s JavaScript re
     if (this.hasContent() && this.enabled) {
       this.$element.trigger(e)
 
-      var inDom = $.contains(document.documentElement, this.$element[0])
+      var inDom = $.contains(this.$element[0].ownerDocument.documentElement, this.$element[0])
       if (e.isDefaultPrevented() || !inDom) return
       var that = this
 
@@ -1459,6 +1459,10 @@ if (typeof jQuery === 'undefined') { throw new Error('Bootstrap\'s JavaScript re
     var isSvg  = window.SVGElement && el instanceof window.SVGElement
 
     var elRect    = el.getBoundingClientRect()
+    if (elRect.width == null) {
+      // width and height are missing in IE8, so compute them manually; see https://github.com/twbs/bootstrap/issues/14093
+      elRect = $.extend({}, elRect, { width: elRect.right - elRect.left, height: elRect.bottom - elRect.top })
+    }
     var elOffset  = isBody ? { top: 0, left: 0 } : $element.offset()
     var scroll    = { scroll: isBody ? document.documentElement.scrollTop || document.body.scrollTop : $element.scrollTop() }
     var outerDims = isSvg ? {} : {
@@ -2170,8 +2174,8 @@ if (typeof jQuery === 'undefined') { throw new Error('Bootstrap\'s JavaScript re
 
       data.offset = data.offset || {}
 
-      if (data.offsetBottom) data.offset.bottom = data.offsetBottom
-      if (data.offsetTop)    data.offset.top    = data.offsetTop
+      if (data.offsetBottom != null) data.offset.bottom = data.offsetBottom
+      if (data.offsetTop    != null) data.offset.top    = data.offsetTop
 
       Plugin.call($spy, data)
     })

docs/dist/js/bootstrap.js

@@ -1282,7 +1282,7 @@ if (typeof jQuery === 'undefined') { throw new Error('Bootstrap\'s JavaScript re
     if (this.hasContent() && this.enabled) {
       this.$element.trigger(e)
 
-      var inDom = $.contains(document.documentElement, this.$element[0])
+      var inDom = $.contains(this.$element[0].ownerDocument.documentElement, this.$element[0])
       if (e.isDefaultPrevented() || !inDom) return
       var that = this
 
@@ -1459,6 +1459,10 @@ if (typeof jQuery === 'undefined') { throw new Error('Bootstrap\'s JavaScript re
     var isSvg  = window.SVGElement && el instanceof window.SVGElement
 
     var elRect    = el.getBoundingClientRect()
+    if (elRect.width == null) {
+      // width and height are missing in IE8, so compute them manually; see https://github.com/twbs/bootstrap/issues/14093
+      elRect = $.extend({}, elRect, { width: elRect.right - elRect.left, height: elRect.bottom - elRect.top })
+    }
     var elOffset  = isBody ? { top: 0, left: 0 } : $element.offset()
     var scroll    = { scroll: isBody ? document.documentElement.scrollTop || document.body.scrollTop : $element.scrollTop() }
     var outerDims = isSvg ? {} : {
@@ -2170,8 +2174,8 @@ if (typeof jQuery === 'undefined') { throw new Error('Bootstrap\'s JavaScript re
 
       data.offset = data.offset || {}
 
-      if (data.offsetBottom) data.offset.bottom = data.offsetBottom
-      if (data.offsetTop)    data.offset.top    = data.offsetTop
+      if (data.offsetBottom != null) data.offset.bottom = data.offsetBottom
+      if (data.offsetTop    != null) data.offset.top    = data.offsetTop
 
       Plugin.call($spy, data)
     })