Fix [#22121] Object Mapping - "clone" linked w/previous material/texture

after Make Single User

Was an error in UI display of node materials/texture lists, combined with a 
very weird node setup.

I will be a very happy person the day we finally get rid of the terribly 
confusing materials-inside-materials behaviour.

release/scripts/ui/properties_texture.py

@@ -45,11 +45,12 @@ class TEXTURE_MT_envmap_specials(bpy.types.Menu):
         layout.operator("texture.envmap_clear", icon='FILE_REFRESH')
         layout.operator("texture.envmap_clear_all", icon='FILE_REFRESH')
 
+from properties_material import active_node_mat
 
 def context_tex_datablock(context):
     idblock = context.material
     if idblock:
-        return idblock
+        return active_node_mat(idblock)
 
     idblock = context.lamp
     if idblock: