Check license info for qt/serviceHelper.py and set correct SPDX meta data.
Was initially reported here 61a858d#r146500622

Current situation

The main problem is that it is unclear to which copyright holder or license any of the code is related to.

The file mentions several licenses and copyright holders:

• (from BackInTime) Copyright (C) 2015-2015 Germar Reitze mention GPL-2.0-or-later
• (from jockey) (c) 2008 Canonical Ltd. mention GPL-2.0-or-later
• (from python-dbus-docs) Copyright (C) 2004-2006 Red Hat Inc. <http://www.redhat.com/> Copyright (C) 2005-2007 Collabora Ltd. <http://www.collabora.co.uk/> with an unclear license statement not mention a license name.
• A final note about David D. Lowe modified that file in 2009 mention CC0-1.0.

Research

• I don't see any helpful information in the git history of that file.
• BIT was at launchpad before. But even there I can not find useful information in the repos history. https://bazaar.launchpad.net/~bit-team/backintime/main/view/head:/qt/serviceHelper.py
• I contacted jockey project and asked for a short review of the file and if one of the code blocks is familiar to them.
• The python-dbus-docs might be related to dbus-python/tutorial.html where you can find the exact same license notice at the end of the doc file. Also the name "Collabora" is mentioned. It seems to be the MIT license. What a stupid license text, when it doesn't mention its own name! 👿
• I opened an issue at dbus-python and ask about how to handle/license code snippets from the tutorial/docu.
• Mr. Lowe: I was not able to find a good match. But I tried to contact two Mr. Lowe (one is computer scientist and the other a medical doctor). But if the "D." in is not a typo then they might not be the right Mr. Lowe.
• @Germar Do you remember about this file and can add some useful information?

Suggested solution

Looking into the python-dbus tutorial I would say the code snippets do not have enough "creative value" (German: Schöpferischen Wert) in a legal sense. So there is no way to license them at all. Anyway, lets pretend even the code snippets are MIT licensed. ☮️

• SPDX does allow multiple license for one file. Let's make it so because this is valid:

  # SPDX-License-Identifier: GPL-2.0-or-later
  # SPDX-License-Identifier: MIT
  

• Additionally add some extra info in the file comment that explain the origin of the code and the difficulties in specifically attributing individual code parts to their sources and licenses.
• MIT also allows to re-license content as GPL