license_image.bbclass: check and reject packages which have incompatible licenses
The use case is setting INCOMPATIBLE_LICENSE per image,
rather than as an awkward, and too strict global setting.
This for example would allow building development images with gplv3 tools,
but production images without them, and checking that nothing gpl3-licensed
gets into the latter.
Examples are provided via the selftest: four scenarios are tested:
- bash is added to the image, with a default gpl3 license; this is rejected
- bash is added to the image, with a "gpl3 & other" license; this is also rejected
- bash is added to the image, with a "gpl3 | other" license; this is accepted, but
only 'other' is added to the license manifest (this was already handled correctly
previously).
- bash is added to the image with a default gpl3 license, and is additionally
whitelisted for that image; this is accepted.
Eventually, this would allow deprecating the meta-gplv2 layer, while still
enforcing the no-gpl3 rule where possible and needed.
Signed-off-by: Alexander Kanavin <alex.kanavin@gmail.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
