global-auto-composition-mode doesn't work in echo area buffer

[Kenichi Handa]

Currently a message string shown in echo area can't be
composed.  For instance, try this.
  (message "हिंदी")

This is because auto-composition-function is nil in " *Echo
Area 0*" buffer even if global-auto-composition-mode is t.
global-auto-composition-mode is defined as below.

(define-global-minor-mode global-auto-composition-mode
  auto-composition-mode turn-on-auto-composition-if-enabled
  ;; This :extra-args' appears to be the result of a naive copy&paste
  ;; from global-font-lock-mode.
  ;; :extra-args (dummy)
  :initialize 'custom-initialize-delay
  :init-value (not noninteractive)
  :group 'auto-composition
  :version "23.1")

Once I eval this manually:

(with-current-buffer " *Echo Area 0*"
  (setq auto-composition-function 'auto-compose-chars))

a message shown in echo area is composed correctly.

Could someone tell me how to run
turn-on-auto-composition-if-enabled in all buffers for echo
area automatically?

---
Kenichi Handa
address@hidden