Merge lp:~ubuntu-mate-dev/ubiquity/mate-compatibility into lp:ubiquity

[Martin Wimpress]

The Ubuntu MATE seeds/meta-packages have been modified to follow Recommends. This means that unity-control-center and unity-settings-daemon are now unavoidably seeded in Ubuntu MATE 16.10 as they are pulled in via libaccount-plugin-1.0-0 which includes Recommends: unity-control-center-signon

This merge proposal changes the order the settings daemons are attempted to be started in ubiquity-dm. mate-settings-daemon is now first. This will not introduce any issues for Ubuntu or Ubuntu GNOME because neither seed anything that might pull in mate-settings-daemon.

[Mathieu Trudel-Lapierre (cyphermox)]

Seems like whatever pulls in u-s-d and/or g-s-d should be fixed (add an alternate Depends on the right settings-daemon, instead of reordering things here).

If some other package Depends on u-s-d, it probably already also depends on u-s-d | g-s-d. In this sense, it makes sense to add "| m-s-d" rather than modifying the order in which things are loaded here.

review: Needs Fixing

[Mathieu Trudel-Lapierre (cyphermox)]

Sounds like there is decent justification for having the change after all; approved.

FTR; there is a complex chain of dependencies from wanting to land shotwell, which suggests some account-plugin-* packages which in turn will eventually depend on u-s-d magic. Having u-s-d in the image would make it loaded first by ubiquity-dm, since it's evaluated first.

review: Approve

=== modified file 'bin/ubiquity-dm'
--- bin/ubiquity-dm	2016-04-18 15:19:40 +0000
+++ bin/ubiquity-dm	2016-06-13 12:01:35 +0000
@@ -451,11 +451,16 @@
                         stdin=null, stdout=logfile, stderr=logfile,
                         preexec_fn=self.drop_privileges)
 
+                msd = '/usr/bin/mate-settings-daemon'
                 usd = '/usr/lib/unity-settings-daemon/unity-settings-daemon'
                 gsd = '/usr/lib/gnome-settings-daemon/gnome-settings-daemon'
-                msd = '/usr/bin/mate-settings-daemon'
-
-                if osextras.find_on_path(usd):
+
+                if osextras.find_on_path(msd):
+                    extras.append(subprocess.Popen(
+                        [msd], stdin=null, stdout=logfile, stderr=logfile,
+                        preexec_fn=self.drop_privileges))
+
+                elif osextras.find_on_path(usd):
                     extras.append(subprocess.Popen(
                         [usd], stdin=null, stdout=logfile, stderr=logfile,
                         preexec_fn=self.drop_privileges))
@@ -465,11 +470,6 @@
                         [gsd], stdin=null, stdout=logfile, stderr=logfile,
                         preexec_fn=self.drop_privileges))
 
-                elif osextras.find_on_path(msd):
-                    extras.append(subprocess.Popen(
-                        [msd], stdin=null, stdout=logfile, stderr=logfile,
-                        preexec_fn=self.drop_privileges))
-
                 elif background_image and osextras.find_on_path('feh'):
                     subprocess.call(
                         ['feh', '--bg-fill', background_image],