From cf7fcda1374491cc73a751d5636f36a95b2e8669 Mon Sep 17 00:00:00 2001 From: Spencer Baugh Date: Thu, 21 Sep 2023 21:35:50 -0400 Subject: [PATCH] Add server-eval-args-left to server.el Passing arbitrary arguments to functions through emacsclient --eval requires complicated escaping to avoid them being parsed as Lisp (as seen in emacsclient-mail.desktop before this change). This new variable server-eval-args-left allows access to the arguments before they are parsed as Lisp. By removing arguments from the variable before they're parsed, a snippet of Lisp can consume arguments, as in emacsclient-mail.desktop. org-protocol might be able to use this as well, which might allow it to drop its current advice on server-visit-files. * etc/emacsclient-mail.desktop: Use server-eval-args-left. (bug#65902) * lisp/server.el (server-eval-args-left): Add. (server-process-filter, server-execute): Make -eval arguments available through server-eval-args-left. * lisp/startup.el (argv): Mention server-eval-args-left in docstring. * etc/NEWS: Announce server-eval-args-left. --- etc/NEWS | 10 ++++++++++ etc/emacsclient-mail.desktop | 7 ++----- lisp/server.el | 35 ++++++++++++++++++++++++++++------- lisp/startup.el | 5 ++++- 4 files changed, 44 insertions(+), 13 deletions(-) diff --git a/etc/NEWS b/etc/NEWS index cd4c414a64c..de1d79fcb98 100644 --- a/etc/NEWS +++ b/etc/NEWS @@ -121,6 +121,16 @@ Anything following the symbol 'mode-line-format-right-align' in right-aligned to is controlled by the new user option 'mode-line-right-align-edge'. +** Emacs Server and Client + +--- +*** 'server-eval-args-left' can be used to pop subsequent eval args +When '--eval' is passed to emacsclient and Emacs is evaluating each +argument, this variable is set to those which have not yet been +evaluated. It can be used to 'pop' arguments to prevent them from +being evaluated, which is useful when those arguments contain +arbitrary data. + * Editing Changes in Emacs 30.1 diff --git a/etc/emacsclient-mail.desktop b/etc/emacsclient-mail.desktop index 0a2420ddead..5962fa1764c 100644 --- a/etc/emacsclient-mail.desktop +++ b/etc/emacsclient-mail.desktop @@ -1,10 +1,7 @@ [Desktop Entry] Categories=Network;Email; Comment=GNU Emacs is an extensible, customizable text editor - and more -# We want to pass the following commands to the shell wrapper: -# u=$(echo "$1" | sed 's/[\"]/\\&/g'); exec emacsclient --alternate-editor= --display="$DISPLAY" --eval "(message-mailto \"$u\")" -# Special chars '"', '$', and '\' must be escaped as '\\"', '\\$', and '\\\\'. -Exec=sh -c "u=\\$(echo \\"\\$1\\" | sed 's/[\\\\\\"]/\\\\\\\\&/g'); exec emacsclient --alternate-editor= --display=\\"\\$DISPLAY\\" --eval \\"(message-mailto \\\\\\"\\$u\\\\\\")\\"" sh %u +Exec=emacsclient --alternate-editor= --eval '(message-mailto (pop server-eval-args-left))' %u Icon=emacs Name=Emacs (Mail, Client) MimeType=x-scheme-handler/mailto; @@ -16,7 +13,7 @@ Actions=new-window;new-instance; [Desktop Action new-window] Name=New Window -Exec=sh -c "u=\\$(echo \\"\\$1\\" | sed 's/[\\\\\\"]/\\\\\\\\&/g'); exec emacsclient --alternate-editor= --create-frame --eval \\"(message-mailto \\\\\\"\\$u\\\\\\")\\"" sh %u +Exec=emacsclient --alternate-editor= --create-frame --eval '(message-mailto (pop server-eval-args-left))' %u [Desktop Action new-instance] Name=New Instance diff --git a/lisp/server.el b/lisp/server.el index c3325e5a24c..65f28cdea23 100644 --- a/lisp/server.el +++ b/lisp/server.el @@ -1189,6 +1189,7 @@ server-process-filter parent-id ; Window ID for XEmbed dontkill ; t if client should not be killed. commands + evalexprs dir use-current-frame frame-parameters ;parameters for newly created frame @@ -1319,8 +1320,7 @@ server-process-filter (let ((expr (pop args-left))) (if coding-system (setq expr (decode-coding-string expr coding-system))) - (push (lambda () (server-eval-and-print expr proc)) - commands) + (push expr evalexprs) (setq filepos nil))) ;; -env NAME=VALUE: An environment variable. @@ -1345,7 +1345,7 @@ server-process-filter ;; arguments, use an existing frame. (and nowait (not (eq tty-name 'window-system)) - (or files commands) + (or files commands evalexprs) (setq use-current-frame t)) (setq frame @@ -1394,7 +1394,7 @@ server-process-filter (let ((default-directory (if (and dir (file-directory-p dir)) dir default-directory))) - (server-execute proc files nowait commands + (server-execute proc files nowait commands evalexprs dontkill frame tty-name))))) (when (or frame files) @@ -1404,22 +1404,43 @@ server-process-filter ;; condition-case (t (server-return-error proc err)))) -(defun server-execute (proc files nowait commands dontkill frame tty-name) +(defvar server-eval-args-left nil + "List of eval args not yet processed. + +When the server receives a request to eval one or more strings, +it stores them in this variable. Then, until this variable is +nil, it `pop's a string from this variable and evaluates it with +`server-eval-and-print'. Adding or removing strings from this +variable during this process will affect what is evaluated. + +This allows an expression passed to \"emacsclient --eval\" to +consume one or more subsequent arguments before they're parsed or +evaluated, with (pop server-eval-args-left). This is useful if +those arguments are arbitrary strings which should not be +evaluated. + +See also `command-line-args-left' for a similar variable which +works for command line invocations of \"emacs\".") + +(defun server-execute (proc files nowait commands evalexprs dontkill frame tty-name) ;; This is run from timers and process-filters, i.e. "asynchronously". ;; But w.r.t the user, this is not really asynchronous since the timer ;; is run after 0s and the process-filter is run in response to the ;; user running `emacsclient'. So it is OK to override the - ;; inhibit-quit flag, which is good since `commands' (as well as + ;; inhibit-quit flag, which is good since `evalexprs' (as well as ;; find-file-noselect via the major-mode) can run arbitrary code, ;; including code that needs to wait. (with-local-quit (condition-case err (let ((buffers (server-visit-files files proc nowait))) (mapc 'funcall (nreverse commands)) + (let ((server-eval-args-left (nreverse evalexprs))) + (while server-eval-args-left + (server-eval-and-print (pop server-eval-args-left) proc))) ;; If we were told only to open a new client, obey ;; `initial-buffer-choice' if it specifies a file ;; or a function. - (unless (or files commands) + (unless (or files commands evalexprs) (let ((buf (cond ((stringp initial-buffer-choice) (find-file-noselect initial-buffer-choice)) diff --git a/lisp/startup.el b/lisp/startup.el index 7f601668369..f2c84751211 100644 --- a/lisp/startup.el +++ b/lisp/startup.el @@ -120,7 +120,10 @@ command-switch-alist "List of command-line args not yet processed. This is a convenience alias, so that one can write (pop argv) inside of --eval command line arguments in order to access -following arguments.")) +following arguments. + +See also `server-eval-args-left' for a similar variable which +works for invocations of \"emacsclient --eval\".")) (internal-make-var-non-special 'argv) (defvar command-line-args-left nil -- 2.41.0