Appdata has ‘proprietary’ license (due to CC-BY-SA-3.0)
This is the very same issue reported against GNOME Mahjongg at gnome-mahjongg#28 which states:
...in the SPDX language, the use of
andmeans that the terms of both licenses must be complied with.
CC-BY-SA-3.0is not an FSF or OSI approved license, so this leads to Meld being shown as proprietary in gnome-software.
The appdata file for Meld contains
<project_license>GPL-2.0+ and CC-BY-SA-3.0</project_license>. See https://gitlab.gnome.org/GNOME/meld/-/blob/master/data/org.gnome.meld.appdata.xml.in.in#L10
COPYINGfile only contains the GPL-2.0+, so I guess the
CC-BY-SA-3.0clause was added to the SPDX description because the documentation is licensed under that?
This has been reported also at https://discussion.fedoraproject.org/t/meld-has-wrong-license-in-registry-fedoraproject-org/29555/3