Properly check for a class, rather than an instance. This has been broken for a long time, and it was pure accident it previously worked due to the proper handling in tag_function.
Properly check for a class, rather than an instance. This has been broken for a long time, and it was pure accident it previously worked due to the proper handling in tag_function.

rossowl/coffin,akx/coffin,rossowl/coffin