bug#26412: 26.0.50; Minibuffer completion for "C-h f" probes unrelated stuff

[npostavs]

npostavs@users.sourceforge.net writes:

> The essential problem seems to be that
>
> (radix-tree-prefixes (help-definition-prefixes) "default-font-height")
> ;=> (("def" "nnoo" "mode-local" "mh-e" "mh-acros" "cl"))
>
> Actually, (radix-tree-prefixes (help-definition-prefixes) "default")
> produces the same as result, and C-h f default SPC triggers this as
> well.  I can't find any definitions starting with "default" in
> lisp/mh-e/*.el though.

Oh, it's "def" not "default", loaddefs.el has

    ;;;### (autoloads nil "mh-acros" "mh-e/mh-acros.el" (0 0 0 0))
    ;;; Generated autoloads from mh-e/mh-acros.el

    (if (fboundp 'register-definition-prefixes) (register-definition-prefixes 
"mh-acros" '("mh-" "with-mh-folder-updating" "def")))
                                                                                
                                           ^^^^^
Which comes from these macros in lisp/mh/mh-acros.el:

    (defmacro defun-mh (name function arg-list &rest body)

    (defmacro defmacro-mh (name macro arg-list &rest body)