(setf documentation) modifies docstrings of other functions

[Stas Boukarev]

(documentation 'sb-c::optional-dispatch-keyp 'function) returns "A place for clients to stash things."
but that docstring comes from src/code/run-program.lisp:

(setf (documentation 'process-status-hook 'function)
      "A function that is called when PROCESS changes its status.
The function is called with PROCESS as its only argument.")

Doing (require 'sb-concurrency) makes

(documentation 'sb-c::optional-dispatch-keyp 'function) => "Name of a MAILBOX. SETFable."

and sb-mailbox has (setf documentation) with that docstring.

As far as I can tell this only concerns functions generated by DEFSTRUCT.

[Stas Boukarev (stassats)]

I guess because these functions are implemented as closures over a structure, like the following:

(defun foo ()
  (lambda ()))

(defun test ()
  (setf (documentation (foo) 'function) "DOCSTRING")
  (documentation (foo) 'function))

(test) => "DOCSTRING"

[Nikodemus Siivola (nikodemus)]

In 1.0.43.63.