Arrow key listeners for dropdown not reset, causing dropdown to skip records

[sxgrant]

Bug description:

Dropdown (with keyboard-nav) does not remove key-listeners on $document if the user navigates directly between several dropdowns. This results in duplicate arrow-key listen events making the control skip x entries where x is the number of times the user has navigated between dropdowns.

This is especially problematic for users trying to use a form with multiple dropdowns with keyboard only, but if the issue still presents if the user clicks directly between dropdowns and then uses keys to select.

Link to minimally-working plunker that reproduces the issue:

Can be reproduced on the examples page; https://angular-ui.github.io/bootstrap/#/dropdown
Steps:

1. Click the keyboard-navigable dropdown
2. Use the arrows and observe normal behaviour
3. Without closing the dropdown, select another dropdown (e.g. "dropdown on body")
4. Without closing the dropdown, return to the keyboard-navigable dropdown
5. Arrow keys no longer work one-at-a-time

Version of Angular, UIBS, and Bootstrap

Angular:
1.5.8
UIBS:
2.2.0
Bootstrap:
3.3.7

(Chome: 54.0.2840.71)

I'm working around it at the moment by deliberately removing the keydown event on toggle, as below;

this.toggle = function(open) {
    scope.isOpen = arguments.length ? !!open : !scope.isOpen;
    if(scope.isOpen) {
      $document.off('keydown', this.keybindFilter);
    }
    if (angular.isFunction(setIsOpen)) {
      setIsOpen(scope, scope.isOpen);
    }
    return scope.isOpen;
  };

[patricksmms]

I was also looking for a solution for this issue.

[patricksmms]

The code fix is actually pretty simple, just adding to the file dropdown.js, line 275 this:
$document.off('keydown', uibDropdownService.keybindFilter);