--- Begin Message ---
|
Subject: |
25.0.50; PATCH: break potential infinite loop in (line-move-to-column) |
|
Date: |
Sun, 03 May 2015 12:32:33 -0700 |
(line-move-to-column) has a loop that can become infinite:
(while (and ...)
(goto-char (previous-char-property-change (point) line-beg)))
If (= (point) line-beg) then the (goto-char) does nothing, and the
condition in the while never changes. This patch adds a check to break
out of the while when this happens:
(while (and ... (/= (point) line-beg))
(goto-char (previous-char-property-change (point) line-beg)))
I'm seeing this in the wild with ERC and erc-fill-mode disabled. Simply
moving around an ERC buffer can hit this.
>From 4214ce56af49f506729b0240ea1dbb9c588f6215 Mon Sep 17 00:00:00 2001
From: Dima Kogan <address@hidden>
Date: Sun, 3 May 2015 12:31:13 -0700
Subject: [PATCH] * lisp/simple.el (line-move-to-column): break potential
infinite loop
(line-move-to-column) has a loop that can become infinite:
(while (and ...)
(goto-char (previous-char-property-change (point) line-beg)))
If (= (point) line-beg) then the (goto-char) does nothing, and the condition in
the while never changes. This patch adds a check to break out of the while when
this happens:
(while (and ... (/= (point) line-beg))
(goto-char (previous-char-property-change (point) line-beg)))
I'm seeing this in the wild with ERC and erc-fill-mode disabled. Simply moving
around an ERC buffer can hit this.
---
lisp/simple.el | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/lisp/simple.el b/lisp/simple.el
index 31efe38..4873ebd 100644
--- a/lisp/simple.el
+++ b/lisp/simple.el
@@ -5962,7 +5962,8 @@ and `current-column' to be able to ignore invisible text."
;; but with a more reasonable buffer position.
(goto-char normal-location)
(let ((line-beg (line-beginning-position)))
- (while (and (not (bolp)) (invisible-p (1- (point))))
+ (while (and (not (bolp)) (invisible-p (1- (point)))
+ (/= (point) line-beg))
(goto-char (previous-char-property-change (point) line-beg))))))))
(defun move-end-of-line (arg)
--
2.1.4
--- End Message ---
--- Begin Message ---
|
Subject: |
Re: bug#20498: 25.0.50; PATCH: break potential infinite loop in (line-move-to-column) |
|
Date: |
Sat, 09 May 2015 16:08:32 +0300 |
> From: Dima Kogan <address@hidden>
> Cc: address@hidden
> Date: Tue, 05 May 2015 01:29:14 -0700
>
> Hi. Thank you very much for double-checking. It indeed looks like (bolp)
> should cover this case. It doesn't however. When ERC misbehaves in this
> way I observe both
>
> (= (line-beginning-position) (point)) --> t
> (bolp) --> nil
>
> This sounds wrong. Looking at the buffer with my eyes, the point is not
> at the beginning of the line, so it LOOKS like the (bolp) result is
> correct.
>
> The docs for (line-beginning-position) state that this function respects
> field boundaries. If I ignore those explicitly then I see the correct
> behavior:
>
> (let ((inhibit-field-text-motion t))
> (line-beginning-position)) ---> correct start of line
>
> So the correct patch would replace (line-beginning-position) to the
> above expression. This is trivial, and I'm not actually attaching a
> patch. If you want me to, tell me.
Thanks, I pushed such a change.
> (line-beginning-position) is used in quite a few places in emacs, and
> I'm wondering if in many of those uses the intent is to ignore fields.
I don't know, but I guess they will discover this in due time.
--- End Message ---