From: Noam Postavsky <npostavs@gmail.com>
To: 35264@debbugs.gnu.org
Cc: stefan monnier <monnier@iro.umontreal.ca>
Subject: bug#35264: "Match data clobbered by buffer modification hooks" when hooks only shifted match-data's markers
Date: Thu, 30 May 2019 19:03:54 -0400 [thread overview]
Message-ID: <871s0f7det.fsf@gmail.com> (raw)
In-Reply-To: <87h8b119oy.fsf@gmail.com> (Noam Postavsky's message of "Sun, 14 Apr 2019 00:40:13 -0400")
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> I think this is a variant of Bug#23917, there was some talk there about
> removing the check, perhaps that is the right solution.
So, this, I guess.
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From 6fd6605c63ecc031a3fd6ba8b8e2e754c183b3f2 Mon Sep 17 00:00:00 2001
From: Noam Postavsky <npostavs@gmail.com>
Date: Thu, 30 May 2019 19:00:31 -0400
Subject: [PATCH] Remove unreliable test for match data clobbering (Bug#35264)
* src/search.c (Freplace_match): Don't test for change in search_regs
start and end, this is unreliable if change hooks modify text earlier
in the buffer.
---
src/search.c | 18 +++++-------------
1 file changed, 5 insertions(+), 13 deletions(-)
diff --git a/src/search.c b/src/search.c
index db7fecd9ba..1d4550849e 100644
--- a/src/search.c
+++ b/src/search.c
@@ -2730,22 +2730,16 @@ DEFUN ("replace-match", Freplace_match, Sreplace_match, 1, 5, 0,
/* The functions below modify the buffer, so they could trigger
various modification hooks (see signal_before_change and
signal_after_change). If these hooks clobber the match data we
- error out since otherwise this will result in confusing bugs. */
- ptrdiff_t sub_start = search_regs.start[sub];
- ptrdiff_t sub_end = search_regs.end[sub];
+ error out since otherwise this will result in confusing bugs. We
+ used to check for changes in search_regs start and end, but that
+ fails if modification hooks remove or add text earlier in the
+ buffer, so just check num_regs now. */
unsigned num_regs = search_regs.num_regs;
newpoint = search_regs.start[sub] + SCHARS (newtext);
/* Replace the old text with the new in the cleanest possible way. */
replace_range (search_regs.start[sub], search_regs.end[sub],
newtext, 1, 0, 1, 1);
- /* Update saved data to match adjustment made by replace_range. */
- {
- ptrdiff_t change = newpoint - sub_end;
- if (sub_start >= sub_end)
- sub_start += change;
- sub_end += change;
- }
if (case_action == all_caps)
Fupcase_region (make_number (search_regs.start[sub]),
@@ -2755,9 +2749,7 @@ DEFUN ("replace-match", Freplace_match, Sreplace_match, 1, 5, 0,
Fupcase_initials_region (make_number (search_regs.start[sub]),
make_number (newpoint));
- if (search_regs.start[sub] != sub_start
- || search_regs.end[sub] != sub_end
- || search_regs.num_regs != num_regs)
+ if (search_regs.num_regs != num_regs)
error ("Match data clobbered by buffer modification hooks");
/* Put point back where it was in the text. */
--
2.11.0
next prev parent reply other threads:[~2019-05-30 23:03 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-14 4:40 bug#35264: "Match data clobbered by buffer modification hooks" when hooks only shifted match-data's markers Noam Postavsky
2019-05-30 23:03 ` Noam Postavsky [this message]
2020-10-02 4:47 ` Lars Ingebrigtsen
2021-05-12 14:35 ` Lars Ingebrigtsen
2021-05-12 14:55 ` Eli Zaretskii
2021-05-12 15:43 ` Lars Ingebrigtsen
2021-05-12 15:48 ` Eli Zaretskii
2021-05-12 15:57 ` Lars Ingebrigtsen
2021-05-12 16:03 ` Eli Zaretskii
2021-05-13 9:11 ` Lars Ingebrigtsen
2021-05-13 10:14 ` Eli Zaretskii
2021-05-13 16:03 ` Stefan Monnier via Bug reports for GNU Emacs, the Swiss army knife of text editors
2021-05-13 17:09 ` Eli Zaretskii
2021-05-16 13:20 ` Lars Ingebrigtsen
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