View File PATCH_POLICY of Package grub2 (Project home:Ledest:bashisms)
Make sure the patches you add contain tags similar to patches in the kernel RPM. This means, it should contain From, Subject, Patch-mainline tags and also a description of the problem, i.e. what the patch is for. Also, if it is not a SUSE/openSUSE-specific patch (unlikely is), post the patch to upstream too.