Package: emacs;
Reported by: Toby Cubitt <t.s.cubitt.98 <at> cantab.net>
Date: Sat, 21 Jun 2008 15:45:03 UTC
Severity: wishlist
Tags: moreinfo
Fixed in version 28.1
Done: Lars Ingebrigtsen <larsi <at> gnus.org>
Bug is archived. No further changes may be made.
Message #43 received at 459 <at> debbugs.gnu.org (full text, mbox):
From: Lars Ingebrigtsen <larsi <at> gnus.org> To: Eli Zaretskii <eliz <at> gnu.org> Cc: 459 <at> debbugs.gnu.org, monnier <at> iro.umontreal.ca, t.s.cubitt.98 <at> cantab.net Subject: Re: bug#459: Zero-length overlays, overlay keymaps, and `overlays-at' Date: Tue, 20 Jul 2021 13:28:10 +0200
Eli Zaretskii <eliz <at> gnu.org> writes:
> No, please don't make that the default behavior. It makes no sense to
> change the default behavior of such a veteran API for the benefit of a
> rare use case. The gains are very small, and don't justify the risks.
> An optional argument gets us the best of both worlds, so it's a clear
> winner.
I was just hedging in case somebody came up with a brilliant reason for
including them by default. :-)
However... after implementing this, I see that `overlays-in' is
something that exists? And does include zero-length overlays? *sigh*
So `(overlays-in 1 1)' is the answer to this bug report.
I've included the patch that won't be applied below for reference.
Instead I'll just mention `overlays-in' in the `overlays-at' doc string.
diff --git a/src/buffer.c b/src/buffer.c
index d3a5ffd149..93f3e3dbb6 100644
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -2859,7 +2859,8 @@ DEFUN ("kill-all-local-variables", Fkill_all_local_variables,
ptrdiff_t
overlays_at (EMACS_INT pos, bool extend, Lisp_Object **vec_ptr,
ptrdiff_t *len_ptr,
- ptrdiff_t *next_ptr, ptrdiff_t *prev_ptr, bool change_req)
+ ptrdiff_t *next_ptr, ptrdiff_t *prev_ptr, bool change_req,
+ bool include_zero_length)
{
ptrdiff_t idx = 0;
ptrdiff_t len = *len_ptr;
@@ -2886,7 +2887,8 @@ overlays_at (EMACS_INT pos, bool extend, Lisp_Object **vec_ptr,
so its start counts for PREV_PTR if it's before POS. */
if (prev < startpos && startpos < pos)
prev = startpos;
- if (endpos == pos)
+ if (endpos == pos
+ && (!include_zero_length || endpos != startpos))
continue;
if (startpos <= pos)
{
@@ -2928,7 +2930,8 @@ overlays_at (EMACS_INT pos, bool extend, Lisp_Object **vec_ptr,
break;
}
ptrdiff_t endpos = OVERLAY_POSITION (end);
- if (pos < endpos)
+ if (pos < endpos
+ || (include_zero_length && pos == endpos && startpos == endpos))
{
if (idx == len)
{
@@ -4220,10 +4223,13 @@ DEFUN ("overlay-properties", Foverlay_properties, Soverlay_properties, 1, 1, 0,
}
-DEFUN ("overlays-at", Foverlays_at, Soverlays_at, 1, 2, 0,
+DEFUN ("overlays-at", Foverlays_at, Soverlays_at, 1, 3, 0,
doc: /* Return a list of the overlays that contain the character at POS.
-If SORTED is non-nil, then sort them by decreasing priority. */)
- (Lisp_Object pos, Lisp_Object sorted)
+If SORTED is non-nil, then sort them by decreasing priority.
+
+If INCLUDE-ZERO-LENGTH is non-nil, also include zero-length overlays
+at POS. (These are otherwise excluded.) */)
+ (Lisp_Object pos, Lisp_Object sorted, Lisp_Object include_zero_length)
{
ptrdiff_t len, noverlays;
Lisp_Object *overlay_vec;
@@ -4241,7 +4247,7 @@ DEFUN ("overlays-at", Foverlays_at, Soverlays_at, 1, 2, 0,
/* Put all the overlays we want in a vector in overlay_vec.
Store the length in len. */
noverlays = overlays_at (XFIXNUM (pos), 1, &overlay_vec, &len,
- NULL, NULL, 0);
+ NULL, NULL, 0, !NILP (include_zero_length));
if (!NILP (sorted))
noverlays = sort_overlays (overlay_vec, noverlays,
@@ -4317,7 +4323,7 @@ DEFUN ("next-overlay-change", Fnext_overlay_change, Snext_overlay_change,
Store the length in len.
endpos gets the position where the next overlay starts. */
noverlays = overlays_at (XFIXNUM (pos), 1, &overlay_vec, &len,
- &endpos, 0, 1);
+ &endpos, 0, 1, false);
/* If any of these overlays ends before endpos,
use its ending point instead. */
@@ -4364,7 +4370,7 @@ DEFUN ("previous-overlay-change", Fprevious_overlay_change,
Store the length in len.
prevpos gets the position of the previous change. */
overlays_at (XFIXNUM (pos), 1, &overlay_vec, &len,
- 0, &prevpos, 1);
+ 0, &prevpos, 1, false);
xfree (overlay_vec);
return make_fixnum (prevpos);
diff --git a/src/buffer.h b/src/buffer.h
index 24e9c3fcbc..daa666248d 100644
--- a/src/buffer.h
+++ b/src/buffer.h
@@ -1145,7 +1145,8 @@ #define CHECK_FIXNUM_COERCE_MARKER(x) ((x) = make_fixnum (fix_position (x)))
extern void compact_buffer (struct buffer *);
extern void evaporate_overlays (ptrdiff_t);
extern ptrdiff_t overlays_at (EMACS_INT, bool, Lisp_Object **,
- ptrdiff_t *, ptrdiff_t *, ptrdiff_t *, bool);
+ ptrdiff_t *, ptrdiff_t *, ptrdiff_t *, bool,
+ bool);
extern ptrdiff_t sort_overlays (Lisp_Object *, ptrdiff_t, struct window *);
extern void recenter_overlay_lists (struct buffer *, ptrdiff_t);
extern ptrdiff_t overlay_strings (ptrdiff_t, struct window *, unsigned char **);
@@ -1204,13 +1205,13 @@ #define GET_OVERLAYS_AT(posn, overlays, noverlays, nextp, chrq) \
ptrdiff_t maxlen = 40; \
SAFE_NALLOCA (overlays, 1, maxlen); \
(noverlays) = overlays_at (posn, false, &(overlays), &maxlen, \
- nextp, NULL, chrq); \
+ nextp, NULL, chrq, false); \
if ((noverlays) > maxlen) \
{ \
maxlen = noverlays; \
SAFE_NALLOCA (overlays, 1, maxlen); \
(noverlays) = overlays_at (posn, false, &(overlays), &maxlen, \
- nextp, NULL, chrq); \
+ nextp, NULL, chrq, false); \
} \
} while (false)
diff --git a/test/src/buffer-tests.el b/test/src/buffer-tests.el
index 2adffc024a..5e83c0beab 100644
--- a/test/src/buffer-tests.el
+++ b/test/src/buffer-tests.el
@@ -1386,4 +1386,17 @@ buffer-tests-inhibit-buffer-hooks-indirect
(when (buffer-live-p base)
(kill-buffer base)))))))
+(ert-deftest zero-length-overlays-and-not ()
+ (with-temp-buffer
+ (insert "hello")
+ (let ((long-overlay (make-overlay 2 4))
+ (zero-overlay (make-overlay 3 3)))
+ ;; Exclude.
+ (should (= (length (overlays-at 3)) 1))
+ (should (eq (car (overlays-at 3)) long-overlay))
+ ;; Include.
+ (should (= (length (overlays-at 3 nil t)) 2))
+ (should (memq long-overlay (overlays-at 3 nil t)))
+ (should (memq zero-overlay (overlays-at 3 nil t))))))
+
;;; buffer-tests.el ends here
--
(domestic pets only, the antidote for overdose, milk.)
bloggy blog: http://lars.ingebrigtsen.no
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1994-97 Ian Jackson.