Re: What's missing in ELisp that makes people want to use cl-lib?

[João Távora]

On Thu, Nov 9, 2023 at 12:34 PM João Távora <joaotavora@gmail.com> wrote:

> > The following is left as an exercise for the interested readers: take
> > a non-trivial piece of code that you never in your life have laid your
> > eyes upon, and decide what to do with a serious bug report about that
> > code, with or without a patch proposed by someone.  A recent case in
> > point: bug#66970.  Bonus points for doing this with code in a
> > programming language you don't command 110%, like C if you are mainly
> > a Lisp programmer or vice versa.

>  I'll have a better look later.

At first sight, didn't seem terribly hard.  I gave it some basic testing
seems to work like the OP in that bug would like it to.  Could be a start
I guess.  Let me know if you don't like the style.

diff --git a/lisp/leim/quail/hangul.el b/lisp/leim/quail/hangul.el
index 46a2e5a6ba2..c97362b1250 100644
--- a/lisp/leim/quail/hangul.el
+++ b/lisp/leim/quail/hangul.el
@@ -146,21 +146,26 @@ hangul-insert-character
       (progn
         (delete-region (region-beginning) (region-end))
         (deactivate-mark)))
-  (quail-delete-region)
-  (let ((first (car queues)))
-    (insert
-     (hangul-character
-      (+ (aref first 0) (hangul-djamo 'cho (aref first 0) (aref first 1)))
-      (+ (aref first 2) (hangul-djamo 'jung (aref first 2) (aref first 3)))
-      (+ (aref first 4) (hangul-djamo 'jong (aref first 4) (aref first 5))))))
-  (move-overlay quail-overlay (overlay-start quail-overlay) (point))
-  (dolist (queue (cdr queues))
-    (insert
-     (hangul-character
-      (+ (aref queue 0) (hangul-djamo 'cho (aref queue 0) (aref queue 1)))
-      (+ (aref queue 2) (hangul-djamo 'jung (aref queue 2) (aref queue 3)))
-      (+ (aref queue 4) (hangul-djamo 'jong (aref queue 4) (aref queue 5)))))
-    (move-overlay quail-overlay (1+ (overlay-start quail-overlay)) (point))))
+  (let* ((things-to-insert
+          (with-temp-buffer
+            (dolist (queue queues (mapcar #'identity (buffer-string)))
+              (insert
+               (hangul-character
+                (+ (aref queue 0) (hangul-djamo 'cho (aref queue 0)
(aref queue 1)))
+                (+ (aref queue 2) (hangul-djamo 'jung (aref queue 2)
(aref queue 3)))
+                (+ (aref queue 4) (hangul-djamo 'jong (aref queue 4)
(aref queue 5))))))))
+         (may-have-to-overwrite-p
+          (or (= (overlay-start quail-overlay) (overlay-end quail-overlay))
+              (cdr things-to-insert))))
+    (quail-delete-region)
+    (dolist (c things-to-insert)
+      (let ((last-command-event c)
+            (overwrite-mode (and overwrite-mode
+                                 may-have-to-overwrite-p
+                                 overwrite-mode)))
+        (self-insert-command 1)
+        (setq may-have-to-overwrite-p nil)))
+    (move-overlay quail-overlay (1- (point)) (point))))

 (defun hangul-djamo (jamo char1 char2)
   "Return the double Jamo index calculated from the arguments.