From: Eli Zaretskii <eliz@gnu.org>
To: Dmitry Antipov <dmantipov@yandex.ru>
Cc: emacs-devel@gnu.org
Subject: (unknown)
Date: Fri, 29 Jun 2012 16:20:46 +0300 [thread overview]
Message-ID: <83lij66yq9.fsf@gnu.org> (raw)
Dmitry, could you please explain the reason(s) for the change below?
Vertical positions in a window can never be large enough to justify
using ptrdiff_t (on platforms where that is wider than a 32-bit
'int'). These are pixel positions on the Emacs display, so they
cannot be too large. The type of 'first_vpos' looks especially
strange, since it is explicitly set to 1 at most. I'm not aware of a
platform where an 'int' is not wide enough for a value 1 ;-)
Using inappropriate data types makes the code harder to read and
understand, because it hints that something non-obvious is going on
somewhere.
* xdisp.c (try_window_id): Change type of 'first_vpos' and 'vpos'
to ptrdiff_t.
--- src/xdisp.c 2012-06-28 12:29:37 +0000
+++ src/xdisp.c 2012-06-29 11:48:08 +0000
@@ -17761,8 +17761,8 @@ try_window_id (struct window *w)
{
/* Displayed to end of window, but no line containing text was
displayed. Lines were deleted at the end of the window. */
- int first_vpos = WINDOW_WANTS_HEADER_LINE_P (w) ? 1 : 0;
- int vpos = XFASTINT (w->window_end_vpos);
+ ptrdiff_t first_vpos = WINDOW_WANTS_HEADER_LINE_P (w) ? 1 : 0;
+ ptrdiff_t vpos = XFASTINT (w->window_end_vpos);
struct glyph_row *current_row = current_matrix->rows + vpos;
struct glyph_row *desired_row = desired_matrix->rows + vpos;
next reply other threads:[~2012-06-29 13:20 UTC|newest]
Thread overview: 71+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-06-29 13:20 Eli Zaretskii [this message]
2012-06-29 14:18 ` ptrdiff_t misuse [was :Re: (empty)] Dmitry Antipov
2012-06-29 17:07 ` Stefan Monnier
2012-06-30 7:13 ` Paul Eggert
2012-06-30 7:27 ` Eli Zaretskii
2012-06-30 13:12 ` Paul Eggert
2012-06-30 14:23 ` Stefan Monnier
2012-06-30 12:07 ` Stefan Monnier
2012-06-30 13:14 ` Paul Eggert
2012-06-30 14:23 ` Stefan Monnier
2012-07-04 6:25 ` Paul Eggert
2012-07-04 16:39 ` Eli Zaretskii
2012-07-04 18:19 ` Paul Eggert
2012-07-05 16:31 ` Eli Zaretskii
2012-07-05 19:34 ` Eli Zaretskii
2012-07-06 0:08 ` Paul Eggert
2012-07-06 6:43 ` Eli Zaretskii
2012-07-06 7:32 ` Paul Eggert
2012-07-06 8:34 ` ptrdiff_t misuse Eli Zaretskii
2012-07-06 14:51 ` Paul Eggert
2012-07-06 21:30 ` Stefan Monnier
2012-07-06 21:33 ` Samuel Bronson
2012-07-07 10:59 ` Stefan Monnier
2012-07-07 15:34 ` Paul Eggert
2012-07-06 8:46 ` Eli Zaretskii
2012-07-06 10:19 ` Stephen J. Turnbull
2012-07-06 11:01 ` Eli Zaretskii
2012-07-06 12:02 ` Stephen J. Turnbull
2012-07-06 13:37 ` Eli Zaretskii
2012-07-06 16:25 ` Stephen J. Turnbull
2012-07-06 14:56 ` Paul Eggert
2012-07-06 15:43 ` Eli Zaretskii
2012-07-06 15:56 ` Paul Eggert
2012-07-06 16:00 ` Eli Zaretskii
2012-07-06 16:42 ` Dmitry Antipov
2012-07-06 17:39 ` Paul Eggert
2012-07-07 1:31 ` Chong Yidong
2012-06-29 18:54 ` ptrdiff_t misuse [was :Re: (empty)] Eli Zaretskii
-- strict thread matches above, loose matches on Subject: below --
2013-07-04 7:50 (unknown) João Távora
2013-07-06 15:22 ` (unknown) Lars Ingebrigtsen
2013-07-06 17:58 ` (unknown) João Távora
2013-07-06 18:01 ` (unknown) Lars Ingebrigtsen
2014-11-13 15:21 (unknown) Eli Zaretskii
2014-11-13 15:30 ` (unknown) Lars Magne Ingebrigtsen
2015-08-10 13:59 (unknown) David Kastrup
2015-08-10 14:02 ` (unknown) David Kastrup
2016-02-08 7:54 (unknown) steve
2016-02-08 8:01 ` (unknown) Steve Purcell
2016-02-20 15:28 (unknown) Anders Lindgren
2016-09-28 12:26 (unknown) Takesi Ayanokoji
2016-09-29 13:52 ` (unknown) Byung-Hee HWANG (황병희, 黃炳熙)
2016-12-28 7:15 (unknown) Chris Gregory
2016-12-28 8:58 ` (unknown) Andreas Schwab
2017-03-19 16:48 (unknown) Paul Pogonyshev
2017-03-19 19:16 ` (unknown) Mark Oteiza
2017-03-19 19:36 ` (unknown) Paul Pogonyshev
2017-08-30 19:33 (unknown) Mark Oteiza
2018-04-09 23:58 (unknown) siraben
2020-09-06 7:04 (unknown) Ag Ibragimov
2021-07-27 23:54 (unknown) Troy Hinckley
2021-08-23 18:36 (unknown) telegraph
2021-08-23 18:37 (unknown) telegraph
2021-12-20 2:29 (unknown) Davin Pearson
2022-05-29 6:06 (unknown) Pedro Andres Aranda Gutierrez
2022-07-21 11:36 (unknown) Gregory Heytings
2022-10-03 6:30 (unknown) Pedro Andres Aranda Gutierrez
2023-03-13 6:18 (unknown) Pedro Andres Aranda Gutierrez
2023-03-13 6:32 (unknown) Pedro Andres Aranda Gutierrez
2023-11-18 3:13 (unknown) Greg Minshall
2023-11-18 7:05 ` (unknown) Jim Porter
2024-03-13 12:48 (unknown) Eli Zaretskii
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