ui-select (multiple) inside uib-dropdown -- item removal issues

[randolpho]

Bug description:

This may be a duplication of #2120, but there are differences between my report and that, so I'm creating a new bug. My apologies if that's not appropriate. This is also a related two-parter bug; if it should be separate bugs, again, apologies.

Issue 1

Given a ui-select (multiple) that is contained within a uib-dropdown (with auto-close="outsideClick") and has two or more items selected, removing the last item in the list will cause the uib-dropdown to close prematurely.

Issue 2

Given a ui-select (multiple) that is contained within a uib-dropdown and has two or more items selected, removing any item other than the last item will cause the last item to be removed instead. Unlike with Issue 1, this will not prematurely close the uib-dropdown.

Link to minimally-working plunker that reproduces the issue:

The plunker below reproduces both issues.

https://plnkr.co/edit/bWqo72045HzeHbMnf2vZ

Version of Angular, UI-Select, and Bootstrap/Select2/Selectize CSS

Angular: 1.6.1

UI-Select: 0.20.0

angular-ui-bootstrap: 2.5.0