Dash prompt disappears when I type "w" in

[Takeshi Teshima]

Version information:
(1) The release of Ubuntu you are using, via 'lsb_release -rd' or System -> About Ubuntu
$ lsb_release -rd
Description: Ubuntu 16.04.3 LTS
Release: 16.04

(2) The version of the package you are using, via 'apt-cache policy pkgname' or by checking in Software Center
$ apt-cache policy unity
unity:
  インストールされているバージョン: 7.4.0+16.04.20160906-0ubuntu1
  候補: 7.4.0+16.04.20160906-0ubuntu1
  バージョンテーブル:
 *** 7.4.0+16.04.20160906-0ubuntu1 500
        500 http://jp.archive.ubuntu.com/ubuntu xenial-updates/main amd64 Packages
        100 /var/lib/dpkg/status
     7.4.0+16.04.20160415-0ubuntu1 500
        500 http://jp.archive.ubuntu.com/ubuntu xenial/main amd64 Packages

Details:
(3) What you expected to happen
I expected that Dash will not disappear when I type in a single character. I also want to be able to set a keyboard shortcut independent of this behavior.

(4) What happened instead
The prompt area of Unity Dash disappears when I type "w" in the search bar.

Example: A single 'w' (lowercase), or a sequence like "test w" closes the area. However it doesn't happen for "W" (uppercase).

This bug is related to a keyboard shortcut. "Close window" shortcut is set to "Super+w" in my environment, and when I change it to e.g. "Super+q", Dash starts to disappear when I type "q" instead of "w" (and it won't disappear with "w" any longer).

(Just to confirm, when I type in "w", I'm not explicitly pressing "Super")