bug#16346: 24.3; electric-pair-mode close-paren issue

[Leo Liu <sdl.web@gmail.com>]

On 2014-01-11 01:20 +0800, Stefan Monnier wrote:
> I think the idea is fine, but using post-self-insert-hook turns out to
> be a bad idea, I think (tho I liked it, initially).
> Could you try and re-implement it as a minor mode that enables
> eldoc-mode and tweaks eldoc-message-commands buffer-locally, to see if
> that works better?

The following patch seems to do it. Comments?

=== modified file 'lisp/emacs-lisp/eldoc.el'
--- lisp/emacs-lisp/eldoc.el	2014-01-06 23:34:05 +0000
+++ lisp/emacs-lisp/eldoc.el	2014-01-11 04:31:35 +0000
@@ -62,6 +62,11 @@
   :type 'number
   :group 'eldoc)
 
+(defcustom eldoc-print-after-edit nil
+  "If non-nil eldoc info is only shown when editing."
+  :type 'boolean
+  :group 'eldoc)
+
 ;;;###autoload
 (defcustom eldoc-minor-mode-string (purecopy " ElDoc")
   "String to display in mode line when ElDoc Mode is enabled; nil for none."
@@ -150,6 +155,16 @@
   "The function used by `eldoc-message' to display messages.
 It should receive the same arguments as `message'.")
 
+(defvar eldoc-edit-message-commands
+  (let ((cmds (make-vector 31 0))
+	(re (regexp-opt '("delete" "insert" "edit" "electric" "newline"))))
+    (mapatoms (lambda (s)
+		(and (commandp s)
+		     (string-match re (symbol-name s))
+		     (intern (symbol-name s) cmds)))
+	      obarray)
+    cmds))
+
 \f
 ;;;###autoload
 (define-minor-mode eldoc-mode
@@ -168,25 +183,13 @@
   (setq eldoc-last-message nil)
   (if eldoc-mode
       (progn
+	(when eldoc-print-after-edit
+	  (setq-local eldoc-message-commands eldoc-edit-message-commands))
 	(add-hook 'post-command-hook 'eldoc-schedule-timer nil t)
 	(add-hook 'pre-command-hook 'eldoc-pre-command-refresh-echo-area t))
-   (remove-hook 'post-command-hook 'eldoc-schedule-timer)
-   (remove-hook 'pre-command-hook 'eldoc-pre-command-refresh-echo-area)))
-
-;;;###autoload
-(define-minor-mode eldoc-post-insert-mode nil
-  :group 'eldoc :lighter (:eval (if eldoc-mode ""
-				  (concat eldoc-minor-mode-string "|i")))
-  (setq eldoc-last-message nil)
-  (let ((prn-info (lambda ()
-		    (unless eldoc-mode
-		      (eldoc-print-current-symbol-info)))))
-    (if eldoc-post-insert-mode
-	(add-hook 'post-self-insert-hook prn-info nil t)
-      (remove-hook 'post-self-insert-hook prn-info t))))
-
-;; FIXME: This changes Emacs's behavior when the file is loaded!
-(add-hook 'eval-expression-minibuffer-setup-hook 'eldoc-post-insert-mode)
+    (kill-local-variable 'eldoc-message-commands)
+    (remove-hook 'post-command-hook 'eldoc-schedule-timer t)
+    (remove-hook 'pre-command-hook 'eldoc-pre-command-refresh-echo-area t)))
 
 ;;;###autoload
 (defun turn-on-eldoc-mode ()
@@ -264,8 +267,10 @@
 ;; This doesn't seem to be required for Emacs 19.28 and earlier.
 (defun eldoc-pre-command-refresh-echo-area ()
   (and eldoc-last-message
-       (if (eldoc-display-message-no-interference-p)
-           (eldoc-message eldoc-last-message)
+       (if (and (eldoc-display-message-no-interference-p)
+		(symbolp this-command)
+		(intern-soft (symbol-name this-command) eldoc-message-commands))
+	   (eldoc-message eldoc-last-message)
          (setq eldoc-last-message nil))))
 
 ;; Decide whether now is a good time to display a message.
@@ -283,9 +288,7 @@
 ;; Check various conditions about the current environment that might make
 ;; it undesirable to print eldoc messages right this instant.
 (defun eldoc-display-message-no-interference-p ()
-  (and eldoc-mode
-       (not executing-kbd-macro)
-       (not (and (boundp 'edebug-active) edebug-active))))
+  (not (or executing-kbd-macro (bound-and-true-p edebug-active))))
 
 \f
 ;;;###autoload
@@ -309,7 +312,7 @@
   ;; This is run from post-command-hook or some idle timer thing,
   ;; so we need to be careful that errors aren't ignored.
   (with-demoted-errors "eldoc error: %s"
-    (and (or (eldoc-display-message-p) eldoc-post-insert-mode)
+    (and (eldoc-display-message-p)
 	 (if eldoc-documentation-function
 	     (eldoc-message (funcall eldoc-documentation-function))
 	   (let* ((current-symbol (eldoc-current-symbol))

=== modified file 'lisp/simple.el'
--- lisp/simple.el	2014-01-09 01:59:19 +0000
+++ lisp/simple.el	2014-01-11 04:28:32 +0000
@@ -1387,6 +1387,7 @@
         (lambda ()
           (add-hook 'completion-at-point-functions
                     #'lisp-completion-at-point nil t)
+	  (eldoc-mode 1)
           (run-hooks 'eval-expression-minibuffer-setup-hook))
       (read-from-minibuffer prompt initial-contents
                             read-expression-map t