mate-tweak wrongly detects only 2 panel layouts - GNOME2 and OpenSuSE instead of many others

[Norbert]

Steps to reproduce:
1a. Boot Ubuntu MATE 20.10 live session
1b. Have Ubuntu MATE 20.10 installed
2. Launch MATE Tweak
3. Switch to Panel tab
4. Click on *Select panel layout to change the user interface* dropdown menu

Expected results:
* many panel layouts are presented, use can switch to any of it

Actual results:
* only 2 panel layouts are shown - GNOME2 and OpenSuSE instead

ProblemType: Bug
DistroRelease: Ubuntu 20.10
Package: mate-tweak 20.04.0-2
ProcVersionSignature: Ubuntu 5.8.0-18.19-generic 5.8.4
Uname: Linux 5.8.0-18-generic x86_64
NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair
ApportVersion: 2.20.11-0ubuntu45
Architecture: amd64
CasperMD5CheckResult: pass
CasperVersion: 1.452
CurrentDesktop: MATE
Date: Sat Sep 5 16:38:38 2020
LiveMediaBuild: Ubuntu-MATE 20.10 "Groovy Gorilla" - Alpha amd64 (20200905)
PackageArchitecture: all
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: mate-tweak
UpgradeStatus: No upgrade log present (probably fresh install)

[Norbert (nrbrtx)]

Upstream link - https://github.com/ubuntu-mate/mate-tweak/issues/78

[Norbert (nrbrtx)]

Some extra output from the live system:

```
$ dpkg -S .layout
ubuntu-mate-default-settings: /usr/share/mate-panel/layouts/familiar.layout
ubuntu-mate-default-settings: /usr/share/mate-panel/layouts/mutiny.layout
ubuntu-mate-default-settings: /usr/share/mate-panel/layouts/ubuntu-mate.layout
mate-panel: /usr/share/mate-panel/layouts/ubuntu.layout
ubuntu-mate-default-settings: /usr/share/mate-panel/layouts/netbook.layout
mate-panel: /usr/share/mate-panel/layouts/opensuse.layout
ubuntu-mate-default-settings: /usr/share/mate-panel/layouts/pantheon.layout
mate-panel: /usr/share/mate-panel/layouts/default.layout
mate-panel: /usr/share/mate-panel/layouts/mageia.layout
mate-panel: /usr/share/mate-panel/layouts/linuxmint.layout
ubuntu-mate-default-settings: /usr/share/mate-panel/layouts/redmond.layout
ubuntu-mate-default-settings: /usr/share/mate-panel/layouts/eleven.layout
ubuntu-mate-default-settings: /usr/share/mate-panel/layouts/contemporary.layout
mate-panel: /usr/share/mate-panel/layouts/fedora.layout

```

So the panel *layouts* are actually installed.

[Ubuntu QA Website (ubuntuqa)]

This bug has been reported on the Ubuntu ISO testing tracker.

A list of all reports related to this bug can be found here:
http://iso.qa.ubuntu.com/qatracker/reports/bugs/1894386

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Sai Vinoba (saivinoba)]

Layouts are accessible from 'Welcome' application and changeable as well. Only not showing in MATE Tweak.

[Sai Vinoba (saivinoba)]

The condition for `self.indicators_available = True` is not satisfied in `mate-tweak`. The only items listed, 'GNOME2' and 'OpenSUSE' have test `not self.indicators_available` set which is satisfied.

Installing `indicator-datetime` (if you had removed it) and `indicator-session` will get back the full panel list.

Since we are moving to ayatana-indicators the datetime and session conditions need to be updated.

[Launchpad Janitor (janitor)]

This bug was fixed in the package mate-tweak - 20.10.0-0ubuntu1

---------------
mate-tweak (20.10.0-0ubuntu1) groovy; urgency=medium

  * New upstream release. (LP: #1894386)
  * debian/patches:
    + Drop 1002_ensure_object_names_are_distinct.patch. Applied upstream.
    + Drop 1001_adhere_to_hig.patch. Applied upstream.
    + Drop 1000_avoid_killing_brisk_unnecessarily.patch. Applied upstream.

 -- Martin Wimpress <email address hidden> Sun, 20 Sep 2020 12:32:24 +0100

[Norbert (nrbrtx)]

Fixed in 20200921 ISO.