run `gnus-before-do-gcc-hook'.
(message-narrow-to-headers)
(let ((gcc (or gcc (mail-fetch-field "gcc" nil t)))
(cur (current-buffer))
+ (coding-system-for-write 'raw-text)
groups group method)
(when gcc
(message-remove-header "gcc")
(save-excursion
(nnheader-set-temp-buffer " *acc*")
(insert-buffer-substring cur)
+ (run-hooks 'gnus-before-do-gcc-hook)
(goto-char (point-min))
(when (re-search-forward
(concat "^" (regexp-quote mail-header-separator) "$")