notmuch/emacs/notmuch-compat.el
Kyle Meyer 319dcfb50e emacs: restore tag-changes and query bindings for tag hooks
notmuch-before-tag-hook and notmuch-after-tag-hook are supposed to
have access to two dynamic variables, tag-changes and query, but these
were lost with the switch to lexical binding in fc4cda07 (emacs: use
lexical-bindings in all libraries, 2021-01-13).

Add a variant of Emacs's dlet (not available until Emacs 28) and use
it in notmuch-tag to expose tag-changes and query to the hooks.
2021-05-15 08:34:28 -03:00

58 lines
2.2 KiB
EmacsLisp

;;; notmuch-compat.el --- compatibility functions for earlier versions of emacs -*- lexical-binding: t -*-
;;
;; The functions in this file are copied from more modern versions of
;; emacs and are Copyright (C) 1985-1986, 1992, 1994-1995, 1999-2017
;; Free Software Foundation, Inc.
;;
;; This file is part of Notmuch.
;;
;; Notmuch is free software: you can redistribute it and/or modify it
;; under the terms of the GNU General Public License as published by
;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.
;;
;; Notmuch is distributed in the hope that it will be useful, but
;; WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
;; General Public License for more details.
;;
;; You should have received a copy of the GNU General Public License
;; along with Notmuch. If not, see <https://www.gnu.org/licenses/>.
;;; Code:
;; Before Emacs 26.1 lines that are longer than 998 octets were not.
;; folded. Commit 77bbca8c82f6e553c42abbfafca28f55fc995d00 fixed
;; that. Until we drop support for Emacs 25 we have to backport that
;; fix. To avoid interfering with Gnus we only run the hook when
;; called from notmuch-message-mode.
(declare-function mail-header-fold-field "mail-parse" nil)
(defun notmuch-message--fold-long-headers ()
(when (eq major-mode 'notmuch-message-mode)
(goto-char (point-min))
(while (not (eobp))
(when (and (looking-at "[^:]+:")
(> (- (line-end-position) (point)) 998))
(mail-header-fold-field))
(forward-line 1))))
(unless (fboundp 'message--fold-long-headers)
(add-hook 'message-header-hook 'notmuch-message--fold-long-headers))
;; `dlet' isn't available until Emacs 28.1. Below is a copy, with the
;; addition of `with-no-warnings'.
(defmacro notmuch-dlet (binders &rest body)
"Like `let*' but using dynamic scoping."
(declare (indent 1) (debug let))
`(let (_)
(with-no-warnings ; Quiet "lacks a prefix" warning.
,@(mapcar (lambda (binder)
`(defvar ,(if (consp binder) (car binder) binder)))
binders))
(let* ,binders ,@body)))
(provide 'notmuch-compat)
;;; notmuch-compat.el ends here