Annoying call to error in goto-history-element

Annoying call to error in goto-history-element

[Geoff Gole]

When moving through the history of find-file, running into the end of
the history will result in an error message briefly and annoyingly
obscuring the minibuffer. To see this, emacs -q C-x C-f <up>. The
cause is calls to error in goto-history-element.

It looks like in place of error we could call minibuffer-message and
exit the function (see patch below), which would make for a more
pleasant experience. Unfortunately that relies on the fact that the
callers of goto-history-element don't perform any real work after
their call to same, and that doesn't seem like a clean solution.

The only other thing I can think of is writing a macro
with-redirected-error-messages which would catch and redirect Lisp
errors into calls to minibuffer-message, and adding that to the
callers in question. I don't really like that either.

Thoughts?

--- -	2010-12-07 07:30:00.183679773 +0800
+++ simple.el	2010-12-07 07:26:02.000000000 +0800
@@ -1480,37 +1480,37 @@
 	      (minibuffer-contents-no-properties)))
     (if (< nabs minimum)
 	(if minibuffer-default
-	    (error "End of defaults; no next item")
-	  (error "End of history; no default available")))
-    (if (> nabs (length (symbol-value minibuffer-history-variable)))
-	(error "Beginning of history; no preceding item"))
-    (unless (memq last-command '(next-history-element
-				 previous-history-element))
-      (let ((prompt-end (minibuffer-prompt-end)))
-	(set (make-local-variable 'minibuffer-temporary-goal-position)
-	     (cond ((<= (point) prompt-end) prompt-end)
-		   ((eobp) nil)
-		   (t (point))))))
-    (goto-char (point-max))
-    (delete-minibuffer-contents)
-    (setq minibuffer-history-position nabs)
-    (cond ((< nabs 0)
-	   (setq elt (if (listp minibuffer-default)
-			 (nth (1- (abs nabs)) minibuffer-default)
-		       minibuffer-default)))
-	  ((= nabs 0)
-	   (setq elt (or minibuffer-text-before-history ""))
-	   (setq minibuffer-returned-to-present t)
-	   (setq minibuffer-text-before-history nil))
-	  (t (setq elt (nth (1- minibuffer-history-position)
-			    (symbol-value minibuffer-history-variable)))))
-    (insert
-     (if (and (eq minibuffer-history-sexp-flag (minibuffer-depth))
-	      (not minibuffer-returned-to-present))
-	 (let ((print-level nil))
-	   (prin1-to-string elt))
-       elt))
-    (goto-char (or minibuffer-temporary-goal-position (point-max)))))
+	    (minibuffer-message "End of defaults; no next item")
+	  (minibuffer-message "End of history; no default available"))
+      (if (> nabs (length (symbol-value minibuffer-history-variable)))
+	  (minibuffer-message "Beginning of history; no preceding item")
+	(unless (memq last-command '(next-history-element
+				     previous-history-element))
+	  (let ((prompt-end (minibuffer-prompt-end)))
+	    (set (make-local-variable 'minibuffer-temporary-goal-position)
+		 (cond ((<= (point) prompt-end) prompt-end)
+		       ((eobp) nil)
+		       (t (point))))))
+	(goto-char (point-max))
+	(delete-minibuffer-contents)
+	(setq minibuffer-history-position nabs)
+	(cond ((< nabs 0)
+	       (setq elt (if (listp minibuffer-default)
+			     (nth (1- (abs nabs)) minibuffer-default)
+			   minibuffer-default)))
+	      ((= nabs 0)
+	       (setq elt (or minibuffer-text-before-history ""))
+	       (setq minibuffer-returned-to-present t)
+	       (setq minibuffer-text-before-history nil))
+	      (t (setq elt (nth (1- minibuffer-history-position)
+				(symbol-value minibuffer-history-variable)))))
+	(insert
+	 (if (and (eq minibuffer-history-sexp-flag (minibuffer-depth))
+		  (not minibuffer-returned-to-present))
+	     (let ((print-level nil))
+	       (prin1-to-string elt))
+	   elt))
+	(goto-char (or minibuffer-temporary-goal-position (point-max)))))))

 (defun next-history-element (n)
   "Puts next element of the minibuffer history in the minibuffer.

Re: Annoying call to error in goto-history-element

[Lennart Borgman]

On Tue, Dec 7, 2010 at 12:48 AM, Geoff Gole <geoffgole@gmail.com> wrote:
> When moving through the history of find-file, running into the end of
> the history will result in an error message briefly and annoyingly
> obscuring the minibuffer. To see this, emacs -q C-x C-f <up>. The
> cause is calls to error in goto-history-element.
>
> It looks like in place of error we could call minibuffer-message and
> exit the function (see patch below), which would make for a more
> pleasant experience. Unfortunately that relies on the fact that the
> callers of goto-history-element don't perform any real work after
> their call to same, and that doesn't seem like a clean solution.
>
> The only other thing I can think of is writing a macro
> with-redirected-error-messages which would catch and redirect Lisp
> errors into calls to minibuffer-message, and adding that to the
> callers in question. I don't really like that either.
>
> Thoughts?

Is it necessary with a message at all here? Just some kind of visible
"beep" instead perhaps?

Re: Annoying call to error in goto-history-element

[Geoff Gole]

>
> Is it necessary with a message at all here? Just some kind of visible
> "beep" instead perhaps?
>

I would personally prefer a message to a beep. Either way the control
flow problem remains the same.

Re: Annoying call to error in goto-history-element

[Lennart Borgman]

On Tue, Dec 7, 2010 at 1:37 AM, Geoff Gole <geoffgole@gmail.com> wrote:
>>
>> Is it necessary with a message at all here? Just some kind of visible
>> "beep" instead perhaps?
>>
>
> I would personally prefer a message to a beep. Either way the control
> flow problem remains the same.

Yes.