indicator plugin visibility menu missing widgets and texts

[Shevek]

Procedure:

Right-click panel
Select Panel > Panel preferences
Choose items tab
Choose "Indicator plugin" list item
Press settings button on right
Press "Clear known indicators" button

Result:

Barfed up menu. See attached screenshot.
1) The ? icon should be on the left.
2) The blank button should say "OK" or "Yes" or "I don't really understand what this feature does but let's give it a go" or something, not be blank.

ProblemType: Bug
DistroRelease: Ubuntu 15.04
Package: xfce4-indicator-plugin 2.3.3-0ubuntu2
ProcVersionSignature: Ubuntu 3.19.0-9.9-generic 3.19.1
Uname: Linux 3.19.0-9-generic x86_64
ApportVersion: 2.16.2-0ubuntu4
Architecture: amd64
CurrentDesktop: XFCE
Date: Fri Mar 20 20:23:40 2015
InstallationDate: Installed on 2015-03-05 (15 days ago)
InstallationMedia: Xubuntu 14.04.2 LTS "Trusty Tahr" - Release amd64 (20150218.1)
SourcePackage: xfce4-indicator-plugin
UpgradeStatus: Upgraded to vivid on 2015-03-19 (1 days ago)

[Thaddaeus Tintenfisch (thad-fisch-deactivatedaccount)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. The issue you are reporting is an upstream one and it would be nice if somebody having it could send the bug to the developers of the software by following the instructions at https://wiki.ubuntu.com/Bugs/Upstream/Xfce. If you have done so, please tell us the number of the upstream bug (or the link), so we can add a bugwatch that will inform us about its status. Thanks in advance.

[Theo Linkspfeifer (lastonestanding)]

Fixed in 18.04.

Button label:
https://bugzilla.xfce.org/show_bug.cgi?id=13051

Icon placement:
https://git.xfce.org/xfce/libxfce4ui/commit/?id=374e0cbdf394024cf896e489a9be261315dbff37
https://git.xfce.org/xfce/libxfce4ui/commit/?id=43eb0adda91b3d2142cdd6b9f93a4c4637a781a8