bug#6527: C-h b alters key-translation-map (in a bad way)

[David Reitter]

I have reduced bug 6527 to this:

(map-keymap-internal 'ignore 'iso-transl-ctl-x-8-map)

(as called via `keymap_canonicalize')

or also

(keymap-parent  'iso-transl-ctl-x-8-map)

because it seems to be the call to get_keymap with autoloading that is causing 
it.

Indeed we have the following autoload:

;;;***
;;;### (autoloads nil "iso-transl" "international/iso-transl.el"
;;;;;;  (19423 17168))
;;; Generated autoloads from international/iso-transl.el
 (or key-translation-map (setq key-translation-map (make-sparse-keymap)))
 (define-key key-translation-map "\C-x8" 'iso-transl-ctl-x-8-map)
 (autoload 'iso-transl-ctl-x-8-map "iso-transl" "Keymap for C-x 8 prefix." t 
'keymap)


And, merely loading iso-trans.el is documented to create keybindings with Alt.