Can't pass user-defined symbols to apply

[technoblogy]

The first argument to apply can't be something like:

(defun my (x y) (+ x y))
(defvar handlers '(my))
(apply (first handlers) '(0 1)) 
Error: not valid here: my

Note that it affects all platforms, and also affects other functions that take a function argument, such as funcall, mapc, mapcar, sort, etc.

Thanks to @jurov for reporting this.