bug#50443: Fwd: Flyspell error traversal additions

[Roni Kallio <roni@kallio.app>]

>> IMO the best course of action would be to modify
>> `flyspell-goto-next-error' to accept a prefix argument.  The prefix
>> would control the direction and number of jumps performed; negative
>> arguments would jump backwards -ARG errors (by calling
>> flyspell-goto-previous-error), while positive arguments would jump
>> forwards ARG errors.  This would be similar to how commands like
>> `forward-word' handle prefix arguments.  This would allow us to leave
>> the mode-map unchanged, but still distribute the improvement to all
>> users.
>
> Yes, I agree.  Can you change the patch to work this way?

I've been using this updated patch for a while now, hope it comes
through ok.

diff --git a/lisp/textmodes/flyspell.el b/lisp/textmodes/flyspell.el
index 975f540936..b80626bb12 100644
--- a/lisp/textmodes/flyspell.el
+++ b/lisp/textmodes/flyspell.el
@@ -1708,39 +1708,77 @@ flyspell-old-pos-error
 ;;*---------------------------------------------------------------------*/
 ;;*    flyspell-goto-next-error ...                                     */
 ;;*---------------------------------------------------------------------*/
-(defun flyspell-goto-next-error ()
-  "Go to the next previously detected error.
-In general FLYSPELL-GOTO-NEXT-ERROR must be used after
-FLYSPELL-BUFFER."
-  (interactive)
-  (let ((pos (point))
-	(max (point-max)))
-    (if (and (eq (current-buffer) flyspell-old-buffer-error)
-	     (eq pos flyspell-old-pos-error))
-	(progn
-	  (if (= flyspell-old-pos-error max)
-	      ;; goto beginning of buffer
-	      (progn
-		(message "Restarting from beginning of buffer")
-		(goto-char (point-min)))
-	    (forward-word 1))
-	  (setq pos (point))))
-    ;; seek the next error
-    (while (and (< pos max)
-		(let ((ovs (overlays-at pos))
-		      (r '()))
-		  (while (and (not r) (consp ovs))
-		    (if (flyspell-overlay-p (car ovs))
-			(setq r t)
-		      (setq ovs (cdr ovs))))
-		  (not r)))
-      (setq pos (1+ pos)))
-    ;; save the current location for next invocation
-    (setq flyspell-old-pos-error pos)
-    (setq flyspell-old-buffer-error (current-buffer))
-    (goto-char pos)
-    (if (= pos max)
-	(message "No more miss-spelled word!"))))
+(defun flyspell-goto-next-error (&optional arg)
+  "Go to the detected error that is ARG errors forward.
+In general `flyspell-goto-next-error' must be used after
+`flyspell-buffer'."
+  (interactive "p")
+  (cond
+   ((= arg 0) nil)
+   ((< arg 0) (flyspell-goto-previous-error (abs arg)))
+   (t
+    (let ((pos (point))
+	  (max (point-max)))
+      (if (and (eq (current-buffer) flyspell-old-buffer-error)
+	       (eq pos flyspell-old-pos-error))
+	  (progn
+	    (if (= flyspell-old-pos-error max)
+	        ;; goto beginning of buffer
+	        (progn
+		  (message "Restarting from beginning of buffer")
+		  (goto-char (point-min)))
+	      (forward-word 1))
+	    (setq pos (point))))
+      ;; seek the next error
+      (while (and (< pos max)
+		  (let ((ovs (overlays-at pos))
+		        (r '()))
+		    (while (and (not r) (consp ovs))
+		      (if (flyspell-overlay-p (car ovs))
+			  (setq r t)
+		        (setq ovs (cdr ovs))))
+		    (not r)))
+        (setq pos (1+ pos)))
+      ;; save the current location for next invocation
+      (setq flyspell-old-pos-error pos)
+      (setq flyspell-old-buffer-error (current-buffer))
+      (goto-char pos)
+      (if (= pos max)
+	  (message "No more miss-spelled word!")))
+    (flyspell-goto-next-error (1- arg)))))
+
+(defun flyspell-goto-previous-error (&optional arg)
+  "Go to the detected error ARG errors backward.
+In general `flyspell-goto-previous-error' must be used after
+`flyspell-buffer'."
+  (interactive "p")
+  (cond
+   ((= arg 0) nil)
+   ((< arg 0) (flyspell-goto-next-error (abs arg)))
+   (t
+    (let ((min (point-min)))
+      (when (and (eq (current-buffer) flyspell-old-buffer-error)
+                 (eq (point) flyspell-old-pos-error))
+        (when (= (point) min)
+          (message "Restarting from end of buffer")
+          (goto-char (point-max)))
+        (backward-word 1))
+      (while (and (> (point) min)
+                  (let ((ovs (overlays-at (point)))
+                        (r nil))
+                    ;; look for a flyspell overlay
+                    (while (and (not r) (consp ovs))
+                      (if (flyspell-overlay-p (car ovs))
+                          (setq r t)
+                        (setq ovs (cdr ovs))))
+                    (not r)))
+        ;; go to previous word if no overlay was found
+        (backward-word 1))
+      (setq flyspell-old-pos-error (point))
+      (setq flyspell-old-buffer-error (current-buffer))
+      (when (= (point) min)
+        (message "No more miss-spelled word!")))
+    (flyspell-goto-previous-error (1- arg)))))

 ;;*---------------------------------------------------------------------*/
 ;;*    flyspell-overlay-p ...                                           */

> Also, the patch is long enough to require a copyright assignment from
> you.  Would you be willing to start your legal paperwork at this time,
> so we could accept your contribution when it is complete?

Sure, can you direct me to what I need to do to sign?
--
Roni Kallio