Subject: bug#36066: 27.0.50; Error for C-h f in help-fns--first-release

From: Michael Heerdegen <[email-masked]>
Date: Mon, 03 Jun 2019 04:09:40 +0200

Hello,

for some functions I can't show *Help* with C-h f because I get an error
like this:

Debugger entered--Lisp error: (wrong-type-argument integer-or-marker-p nil)
  add-text-properties(nil nil (button (t) category #:help-news-button help-args nil) nil)
  make-text-button(nil nil type help-news help-args nil)
  help-fns--first-release(my-edebug-setup-hook-fun)
  help-fns--mention-first-release(my-edebug-setup-hook-fun)
  run-hook-with-args(help-fns--mention-first-release my-edebug-setup-hook-fun)
  describe-function-1(my-edebug-setup-hook-fun)
  describe-function(my-edebug-setup-hook-fun)

Seems the variable "first" is never set and ends up nil, thus the error.
It often happens to functions in my init file FWIW.

BTW, the calculation/heuristic also seems not very clever in some cases.
E.g. in emacs -Q I define

(defun f () nil)

C-h f f

    f is a Lisp closure.

    (f)

      Probably introduced at or before Emacs version 1.6.

(defun test () nil)

C-h f test

    test is a Lisp closure.

    (test)

      Probably introduced at or before Emacs version 15.

Etc.  Shouldn't it be obvious to Emacs that I defined the functions?

TIA,

Michael