Adjust erc functions after previous erc-pre-send-function change

* lisp/erc/erc-goodies.el (noncommands): Use
erc-pre-send-functions instead of the hook.
(erc-send-distinguish-noncommands): Adjust function to new interface.

* lisp/erc/erc-ring.el (ring): Ditto.
(erc-add-to-input-ring): Ditto.

* lisp/erc/erc.el (erc-send-this): Really make obsolete.
(erc-pre-send-functions): Change to a list of functions to allow
erc-goodies and erc-ring to work as before.

3 files changed, 28 insertions, 20 deletions

diff --git a/lisp/erc/erc-goodies.el b/lisp/erc/erc-goodies.el
index 884c594b9ed..41083829bac 100644
--- a/lisp/erc/erc-goodies.el
+++ b/lisp/erc/erc-goodies.el
@@ -177,18 +177,21 @@ does not appear in the ERC buffer after the user presses ENTER.")
   "This mode distinguishes non-commands.
 Commands listed in `erc-insert-this' know how to display
 themselves."
-  ((add-hook 'erc-send-pre-hook 'erc-send-distinguish-noncommands))
-  ((remove-hook 'erc-send-pre-hook 'erc-send-distinguish-noncommands)))
+  ((push 'erc-send-distinguish-noncommands erc-pre-send-functions))
+  ((setq erc-pre-send-functions (delq 'erc-send-distinguish-noncommands
+                                      erc-pre-send-functions))))
 
 (defun erc-send-distinguish-noncommands (str)
   "If STR is an ERC non-command, set `erc-insert-this' to nil."
   (let* ((command (erc-extract-command-from-line str))
          (cmd-fun (and command
                        (car command))))
-    (when (and cmd-fun
-               (not (string-match "\n.+$" str))
-               (memq cmd-fun erc-noncommands-list))
-      (setq erc-insert-this nil))))
+    (if (and cmd-fun
+             (not (string-match "\n.+$" str))
+             (memq cmd-fun erc-noncommands-list))
+        ;; Inhibit sending this string.
+        nil
+      str)))
 
 ;;; IRC control character processing.
 (defgroup erc-control-characters nil
diff --git a/lisp/erc/erc-ring.el b/lisp/erc/erc-ring.el
index 5459d8b01e5..2ee78f4d46d 100644
--- a/lisp/erc/erc-ring.el
+++ b/lisp/erc/erc-ring.el
@@ -46,10 +46,11 @@
 (define-erc-module ring nil
   "Stores input in a ring so that previous commands and messages can
 be recalled using M-p and M-n."
-  ((add-hook 'erc-send-pre-hook 'erc-add-to-input-ring)
+  ((push 'erc-add-to-input-ring erc-pre-send-functions)
    (define-key erc-mode-map "\M-p" 'erc-previous-command)
    (define-key erc-mode-map "\M-n" 'erc-next-command))
-  ((remove-hook 'erc-send-pre-hook 'erc-add-to-input-ring)
+  ((setq erc-pre-send-functions (delq 'erc-add-to-input-ring
+                                      erc-pre-send-functions))
    (define-key erc-mode-map "\M-p" 'undefined)
    (define-key erc-mode-map "\M-n" 'undefined)))
 
@@ -75,7 +76,8 @@ Call this function when setting up the mode."
   "Add string S to the input ring and reset history position."
   (unless erc-input-ring (erc-input-ring-setup))
   (ring-insert erc-input-ring s)
-  (setq erc-input-ring-index nil))
+  (setq erc-input-ring-index nil)
+  s)
 
 (defun erc-clear-input-ring ()
   "Remove all entries from the input ring, then call garbage-collect.
diff --git a/lisp/erc/erc.el b/lisp/erc/erc.el
index 82360a66f98..0165f2c4703 100644
--- a/lisp/erc/erc.el
+++ b/lisp/erc/erc.el
@@ -1051,16 +1051,17 @@ Note that it's useless to set `erc-send-this' to nil and
 anyway."
   :group 'erc-hooks
   :type 'hook)
-(make-obsolete-variable 'erc-send-pre-hook 'erc-pre-send-function "27.1")
+(make-obsolete-variable 'erc-send-pre-hook 'erc-pre-send-functions "27.1")
 
-(defcustom erc-pre-send-function nil
-  "Function called to possibly alter the string that is sent.
-It's called with one argument, the string, and should return a
-string.
+(defcustom erc-pre-send-functions nil
+  "List of functions called to possibly alter the string that is sent.
+The functions are called with one argument, the string, and
+should return a string.
 
-To suppress the string completely, return nil."
+To suppress the string completely, one of the functions should
+return nil."
   :group 'erc
-  :type 'function
+  :type '(repeat function)
   :version "27.1")
 
 (defvar erc-insert-this t
@@ -1072,7 +1073,7 @@ if they wish to avoid insertion of a particular string.")
   "Send the text to the target or not.
 Functions on `erc-send-pre-hook' can set this variable to nil
 if they wish to avoid sending of a particular string.")
-(make-obsolete-variable 'erc-send-pre-hook 'erc-pre-send-function "27.1")
+(make-obsolete-variable 'erc-insert-this 'erc-pre-send-functions "27.1")
 
 (defcustom erc-insert-modify-hook ()
   "Insertion hook for functions that will change the text's appearance.
@@ -5462,11 +5463,13 @@ This returns non-nil only if we actually send anything."
       ;; The calling convention of `erc-send-pre-hook' is that it
       ;; should change the dynamic variable `str' or set
       ;; `erc-send-this' to nil.  This has now been deprecated:
-      ;; Instead `erc-pre-send-function' is used as a filter to do
+      ;; Instead `erc-pre-send-functions' is used as a filter to do
       ;; allow both changing and suppressing the string.
       (run-hook-with-args 'erc-send-pre-hook input)
-      (when erc-pre-send-function
-	(setq str (funcall erc-pre-send-function str)))
+      (dolist (func erc-pre-send-functions)
+	;; The functions can return nil to inhibit sending.
+	(when str
+	  (setq str (funcall func str))))
       (when (and erc-send-this
 		 str)
         (if (or (string-match "\n" str)