Merge ~macg3/ubuntu/+source/gdebi:fix_pkexec into ubuntu/+source/gdebi:ubuntu/devel

[Doug Brown]

This fixes a longstanding issue that prevents GDebi from working properly when it is launched by a GUI app, such as Firefox or Chrome after downloading a deb file. Ever since Ubuntu 17.10, GDebi just quits immediately when you click Install. It works properly when you run it from a terminal window, but not when launched from Firefox or Chrome. The reason is because pkexec refuses to work if its parent process is init. This change adds an intermediate script that acts as the parent for pkexec.

To test:

- Download a deb file in Firefox/Chrome.
- Open it from within the browser's downloads screen, and choose to open it with GDebi.
- It will open fine. Now, click Install.

Without this change applied, GDebi will immediately quit and the package won't be installed.
After this change is applied, GDebi will successfully install the package.

Another way to test is by directly running GDebi with setsid:

setsid gdebi-gtk package.deb

Without this change, it will fail in the same way. With this change, it will succeed.

The bug that this fixes is Launchpad #1854588. Ideally this would be ported to all of the LTS releases. I'm brand new to this Launchpad workflow, so I'm not sure if there's anything I need to do in order to kickstart this process.

[Robie Basak (racb)]

> I'm brand new to this Launchpad workflow, so I'm not sure if there's anything I need to do in order to kickstart this process.

Sorry, we don't really have a formal way for third parties to submit into this workflow yet - in that there are no reviewers at the other end. To connect the dots, I'm going to link this MP to the bug, and then subscribe ~ubuntu-sponsors to the bug. That way the request will end up in the old sponsorship queue.

Unmerged commits

318f5d2... by Doug Brown <email address hidden> on 2022-01-16

Create separate script to act as pkexec parent

This fixes the issue of GDebi closing immediately when you click Install
after opening a .deb file from inside of Firefox or Chrome.

Fixes LP #1854588

diff --git a/GDebi/GDebiGtk.py b/GDebi/GDebiGtk.py
index e0faa49..23e9109 100644
--- a/GDebi/GDebiGtk.py
+++ b/GDebi/GDebiGtk.py
@@ -602,13 +602,14 @@ class GDebiGtk(SimpleGtkbuilderApp, GDebiCommon):
                 return
 
         if os.getuid() != 0:
-            pkexec_cmd = "/usr/bin/pkexec"
-            pkexec_args = ["pkexec"]
-            gdebi_args = ["gdebi-gtk", "--non-interactive",
+            gdebi_dir = os.path.dirname(os.path.abspath(__file__))
+            pkexec_script = os.path.join(gdebi_dir, "GDebiPkexec.py")
+            gdebi_args = [pkexec_script, "--non-interactive",
                           self._deb.filename]
             if not install:
                 gdebi_args.append("--remove")
-            os.execv(pkexec_cmd, pkexec_args+gdebi_args)
+            os.execv(sys.executable,
+                     [os.path.basename(sys.executable)] + gdebi_args)
 
         if not self.try_acquire_lock():
             if install:
diff --git a/GDebi/GDebiPkexec.py b/GDebi/GDebiPkexec.py
new file mode 100644
index 0000000..b6181b9
--- /dev/null
+++ b/GDebi/GDebiPkexec.py
@@ -0,0 +1,35 @@
+#! /usr/bin/python3
+#
+# AUTHOR:
+# Doug Brown <[e-mail]>
+#
+# This file is part of GDebi
+#
+# GDebi is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License as published
+# by the Free Software Foundation; either version 2 of the License, or (at
+# your option) any later version.
+#
+# GDebi is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with GDebi; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+#
+
+import sys
+import subprocess
+
+# This script exists so that pkexec can be called correctly. GDebiGtk.py cannot
+# directly use os.execv to run pkexec, because when it is called from GUI
+# applications such as Firefox, it is orphaned and thus parented by init. pkexec
+# doesn't like being called like that. This script acts as a parent.
+
+cmd = ["/usr/bin/pkexec", "gdebi-gtk"]
+cmd += sys.argv[1:]
+
+result = subprocess.call(cmd)
+sys.exit(result)