b3af7e8cd6
Fix an assertion that an embedded data-block has a zero 'real user' count. Apparently it's possible for the shader node tree (embedded by the material) to have a user count of 1. Since that looks valid to me (only one user, namely the material itself) I think it's fine to extend the assertion to that. I did keep the assertion, to ensure that the embedded data-block is not shared by multiple users. That shouldn't be possible, in any case. Pull Request: https://projects.blender.org/blender/blender/pulls/130281