Typeahead dropdown disappears in Internet Explorer when blur event and overflow active

[patrick-lewandowski]

Bug description:

Typeahead menu disappears in Internet Explorer when user clicks on scroll bar within dropdown menu.

Link to minimally-working plunker that reproduces the issue:

https://plnkr.co/edit/WUmArnZ9fGLGlbzCjbrf?p=preview

Steps to reproduce the issue:

1. Set typeahead-select-on-blur="true"
2. Set a height and overflow for results, example:

.dropdown-menu {
  max-height: 100px;
  overflow: auto;
}

3. Ensure there is enough data or height is small enough to trigger overflow scroll bar to appear
4. Launch with Internet Explorer (confirmed issue is at least on IE 11)
5. Type a letter into input field to trigger dropdown menu of results to appear
6. Attempt to click on scroll bar arrows or bar itself. At this point, dropdown menu disappears without actually being able to scroll down

Version of Angular, UIBS, and Bootstrap

Angular: 1.6.1

UIBS: 2.5.0

Bootstrap: 3.3.7