data: Fix license blurb and add SPDX-License-Identifier

[pwithnall]

The license blurb mentioned version 2 of the Lesser GPL, which doesn’t
exist — there’s version 2.0 of the Library GPL, or version 2.1 of the
Lesser GPL, but no 2.0 Lesser GPL.

Given that the COPYING file correctly mentions the LGPL 2.1, and the
vast majority of software projects and contributors use version 2.1 in
preference to version 2.0, I think this is a typo which has been
copypastaed across the project.

So, change ‘version 2’ to ‘version 2.1’ in the license blurbs for the
portal API definitions. It’s particularly important that these are
right, because they may well be copied to other projects so that D-Bus
bindings can be generated from them.

In addition, add an SPDX-License-Identifier to the portal API
definitions so the license is machine readable.

Signed-off-by: Philip Withnall pwithnall@gnome.org

[pwithnall]

These changes were all done manually, but should be identical in each file — so if you agree with the rationale for the PR, then this should be an easy review despite the number of files the PR touches.

If you don’t agree with the rationale, then the only other option for fixing the licensing (that I can think of) would be to switch all the affected files to use the Library GPL 2.0 blurb (and appropriate SPDX header).

In any case, having the SPDX-License-Identifier header is very useful, as it allows the licensing to be machine readable, and hence tools like reuse lint can be used to verify the licensing of the entire project automatically. See here for an example of how we use that in GLib’s tests. There’s an introduction to REUSE and SPDX here.

[GeorgesStavracas]

Thanks, I agree with this, seems like the least disruptive way to fix this