Package: emacs;
Reported by: Stefan Monnier <monnier <at> iro.umontreal.ca>
Date: Wed, 31 Jul 2024 07:44:01 UTC
Severity: normal
Found in version 30.0.50
Message #5 received at submit <at> debbugs.gnu.org (full text, mbox):
From: Stefan Monnier <monnier <at> iro.umontreal.ca> To: bug-gnu-emacs <at> gnu.org Subject: 30.0.50; Wrong `next-line` behavior Date: Wed, 31 Jul 2024 03:43:20 -0400
[Message part 1 (text/plain, inline)]
Package: Emacs
Version: 30.0.50
Here's a funny corner case I just bumped into:
- Apply the `smerge-mode.patch` below to Emacs's` master` (and
recompile `smerge-mode.el`).
- Open the short diff file below with:
emacs -Q --eval '(setq-default word-wrap t diff-font-lock-prettify t)' \
.../bug-weird-next-line.diff
- In my case, when this opens there's a "word wrap" just before "This"
and just before "\id{seg}" (on the 4th and 5th lines, resp).
If that's not the case for you, resize your frame so that this is
the case.
- Do `C-n` a few times.
What I see is that `C-n` jumps down to the "T" of the word-wrapped
"This" as it should, but that the next `C-n` doesn't jump to the next
(visual) line but jumps to the "s" of "This" instead.
The same kind of misbehavior occurs on the next (logical) line with
"\id{seg}".
Stefan
[smerge-mode.patch (text/x-diff, inline)]
diff --git a/lisp/vc/smerge-mode.el b/lisp/vc/smerge-mode.el
index a16c7871ff9..05ab757f09a 100644
--- a/lisp/vc/smerge-mode.el
+++ b/lisp/vc/smerge-mode.el
@@ -1034,26 +1034,68 @@ smerge--refine-highlight-change
smerge-refine-forward-function)
startline)
(point)))
- (end (progn (funcall (if smerge-refine-weight-hack
- #'forward-char
- smerge-refine-forward-function)
- (if match-num2
- (- (string-to-number match-num2)
- startline)
- 1))
- (point))))
- (when smerge-refine-ignore-whitespace
- (skip-chars-backward " \t\n" beg) (setq end (point))
- (goto-char beg)
- (skip-chars-forward " \t\n" end) (setq beg (point)))
- (when (> end beg)
+ (end (if (eq t match-num2) beg
+ (funcall (if smerge-refine-weight-hack
+ #'forward-char
+ smerge-refine-forward-function)
+ (if match-num2
+ (- (string-to-number match-num2)
+ startline)
+ 1))
+ (point))))
+ (when (eq t match-num2)
+ ;; FIXME: No idea where this off-by-one comes from!
+ (setq beg (1+ beg))
+ (setq end (1+ end))
+ (goto-char end))
+ (when (and smerge-refine-ignore-whitespace
+ (< beg end))
+ (let* ((newend (progn (skip-chars-backward " \t\n" beg) (point)))
+ (newbeg (progn (goto-char beg)
+ (skip-chars-forward " \t\n" newend) (point))))
+ (unless (eq newend newbeg)
+ (setq end newend)
+ (setq beg newbeg))))
+ (cond
+ ((> end beg)
(let ((ol (make-overlay
beg end nil
;; Make them tend to shrink rather than spread when editing.
'front-advance nil)))
+ (overlay-put ol 'smerge--debug (list match-num1 match-num2 startline))
(overlay-put ol 'evaporate t)
(dolist (x props) (overlay-put ol (car x) (cdr x)))
- ol)))))
+ ol))
+ ((= end beg)
+ (setq end (if (< beg (point-max))
+ (1+ beg)
+ (cl-assert (< (point-min) (point-max)))
+ (setq beg (1- (point-max)))
+ (point-max)))
+ (let ((ol (make-overlay
+ beg end nil
+ ;; Make them tend to shrink rather than spread when editing.
+ 'front-advance nil)))
+ (overlay-put ol 'smerge--debug (list match-num1 match-num2 startline))
+ (overlay-put ol 'evaporate t)
+ ;; Some of the properties need to go to `ol' and others
+ ;; need to go to the string :-(
+ ;; FIXME: I've seen lines in `diff-mode' where the half-space ends up
+ ;; placed at the beginning of the next line rather than the
+ ;; end of the current line, as in:
+ ;;
+ ;; -foo bar
+ ;; + foo bar b
+ ;; ^
+ (overlay-put ol 'before-string
+ (propertize
+ " " 'face (cdr (assq 'face props))
+ 'display '(space :width 0.5)))
+ (dolist (x props)
+ (unless (eq (car-safe x) 'face)
+ (overlay-put ol (car x) (cdr x))))
+ ol))
+ (t (error "Smerge WOW! %S" (list beg end match-num2)))))))
;;;###autoload
(defun smerge-refine-regions (beg1 end1 beg2 end2 props-c &optional preproc props-r props-a)
@@ -1114,20 +1156,18 @@ smerge-refine-regions
(m2 (match-string 2))
(m4 (match-string 4))
(m5 (match-string 5)))
- (when (memq op '(?d ?c))
- (setq last1
- (smerge--refine-highlight-change
- beg1 m1 m2
- ;; Try to use props-c only for changed chars,
- ;; fallback to props-r for changed/removed chars,
- ;; but if props-r is nil then fallback to props-c.
- (or (and (eq op '?c) props-c) props-r props-c))))
- (when (memq op '(?a ?c))
- (setq last2
- (smerge--refine-highlight-change
- beg2 m4 m5
- ;; Same logic as for removed chars above.
- (or (and (eq op '?c) props-c) props-a props-c)))))
+ (setq last1
+ (smerge--refine-highlight-change
+ beg1 m1 (if (eq op ?a) t m2)
+ ;; Try to use props-c only for changed chars,
+ ;; fallback to props-r for changed/removed chars,
+ ;; but if props-r is nil then fallback to props-c.
+ (or (and (eq op '?c) props-c) props-r props-c)))
+ (setq last2
+ (smerge--refine-highlight-change
+ beg2 m4 (if (eq op ?d) t m5)
+ ;; Same logic as for removed chars above.
+ (or (and (eq op '?c) props-c) props-a props-c))))
(forward-line 1) ;Skip hunk header.
(and (re-search-forward "^[0-9]" nil 'move) ;Skip hunk body.
(goto-char (match-beginning 0))))
[bug-weird-next-line.diff (text/x-diff, inline)]
@@ -2004,7 +2538,8 @@
equivalent to a function out of the interval. Its defining characteristic is
-that the output of such a function has to agree at both endpoints of $\bI$. This
-is enforced by the elimination principle of the $\bI$ that ensures that \id{seg}
+that the output of such a function has to agree at both endpoints of $\bI$.
+This is enforced by the elimination principle of the $\bI$ that ensures that
+\id{seg} is respected.
\begin{minted}[escapeinside=@@,mathescape=true]{agda}
type I
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