When creating nodes by dragging a link, it can be convenient to transfer values from input socket. For reference values, like images, this may be necessary to avoid unnecessary data-block users. This patch starts adding such a system. At this moment this only makes sense for one node (Image Input), but this can be extended to work with other reference types, different non-reference types and support auto-casting (if a float is transferred to the Integer Input node). See task: blender/blender#102854 Original patch: https://archive.blender.org/developer/D16735 Pull Request: blender/blender#105972