Merge ~juliank/ubiquity:autopurge into ubiquity:master

[Julian Andres Klode]

[Julian Andres Klode (juliank)]

Maybe this is a bit crude, and it should only do the new autoremovable hack that unattended-upgrades does, as we otherwise might end up removing auto-removable packages unrelated to the list of packages we are removing.

OTOH, that might complicate things, and we'd end up with unrelated autoremovable packages on the target.

[Julian Andres Klode (juliank)]

Verified that the fix worked by copying plugininstall.py to today's kubuntu live image and then running ubiquity: I see log entries about which packages where autopurged, and I can run autoremove in the target without any packages being removed :-)

[Julian Andres Klode (juliank)]

I kept the log message, as it might otherwise be quite hard to figure out that a package was removed due to autopurge.

[Jean-Baptiste Lallement (jibel)]

Thanks for the patch. I verified the fix on Ubuntu with a normal and a minimal installation with Ubuntu focal 20191211 and it works as expected.

The list of packages autoremoved looks ok, and there is no package left to autoremove after installation.

Approved.

review: Approve

diff --git a/debian/changelog b/debian/changelog
index bfb24ce..94095e3 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,3 +1,10 @@
+ubiquity (20.04.4) UNRELEASED; urgency=medium
+
+  * When removing packages, also remove automatically installed packages that
+    are no longer required (LP: #1798992)
+
+ -- Julian Andres Klode <[e-mail]>  Mon, 09 Dec 2019 10:43:45 +0100
+
 ubiquity (20.04.3) focal; urgency=medium
 
   [ Michael Hudson-Doyle ]
diff --git a/scripts/plugininstall.py b/scripts/plugininstall.py
index e772cbf..c3c648d 100755
--- a/scripts/plugininstall.py
+++ b/scripts/plugininstall.py
@@ -1008,6 +1008,12 @@ class Install(install_misc.InstallBase):
         with cache.actiongroup():
             install_misc.get_remove_list(cache, to_remove, recursive)
 
+        with cache.actiongroup():
+            for cachedpkg in cache:
+                if cachedpkg.is_auto_removable and not cachedpkg.marked_delete:
+                    syslog.syslog("Autopurge %s" % cachedpkg.name)
+                    cachedpkg.mark_delete(auto_fix=False, purge=True)
+
         self.db.progress('SET', 1)
         self.progress_region(1, 5)
         fetchprogress = install_misc.DebconfAcquireProgress(