alt-tab is showing preview even if you have just one instance

[Didier Roche-Tolomelli]

alt-tab is supposed to not show a preview of you only have one instance of an application (told JohnLea)
However:

Using unity 5.4 candidate from the staging ppa:

- go on a workspace, run an application, let's say gedit
- go to an empty workspace, middle click on gedit in the launcher to open a second instance
- alt-tab to gedit wait
-> a preview of one window (the one in the current ws) appear

-> the preview shouldn't appear on wait.

[Sebastien Bacher (seb128)]

confirmed

[Launchpad Janitor (janitor)]

This bug was fixed in the package unity - 5.6.0-0ubuntu1

---------------
unity (5.6.0-0ubuntu1) precise; urgency=low

  * New upstream release.
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