Clicking into text input field within dropdown closes the dropdown

Created by: FrenchHipster

Hi,

Please follow this JSfiddle for a live example: https://jsfiddle.net/znbtb8cp/1/

Steps to reproduce:

1. Click on the dropdown button
2. Click on the input field

Expected behaviour: The field should be focused.

Actual behaviour: The dropdown closes.

The project we are working on encountered this issue, and we have a workaround, but we are ready to provide a patch and a pull request with a better/long term solution if nobody has done it yet.