From: Steven Penny <svnpenn@gmail.com>
To: cygwin@cygwin.com
Subject: Re: Cygwin fails to utilize Unicode replacement character
Date: Tue, 04 Sep 2018 23:29:00 -0000 [thread overview]
Message-ID: <5b8f1539.1c69fb81.3d7fb.2575@mx.google.com> (raw)
In-Reply-To: <5c366e53-ad20-7ccc-5d76-c4fd5adefdf9@towo.net>
On Tue, 4 Sep 2018 23:43:16, Thomas Wolff wrote:
> Traditionally, many terminals used to display the DEL character as a
> checkered block, which is more or less the MEDIUM SHADE.
> This makes the glyph appear somewhat "erroneous" by convention.
I see - now that Unicode has some dedicated characters for this, it would make
sense to use them, especially since linux is already using them:
1. U+FFFD: http://unicode.org/charts/nameslist/n_FFF0.html
2. U+25A1: http://unicode.org/charts/nameslist/n_25A0.html
> valid code point with no glyph in font -> .notdef glyph -> WHITE SQUARE
this is not true. "WHITE SQUARE" refers to U+25A1, which is an actual character
and different from the ".notdef" glyph. as has been discussed as length in this
thread, the ".notdef glyph" is not an actual character, but a glyph that exists
at position 0 in the font, and while its appearance is not strictly defined,
some recommendations exist:
- empty rectangle
- rectangle with a question mark
- rectangle with an X
> Now if you switch to FFFD REPLACEMENT CHARACTER for invalid code point,
> and considering that it does not exist in most actual fonts and that the
> console does not apply font fallback, it will resolve to WHITE SQUARE, thus:
> folding the two different use cases into the same appearance,
> which is bad.
no again, it will resolve to ".notdef glyph", as I put above. otherwise yes, you
do have a point. in the case of a font without U+FFFD, you have ultimately:
invalid code point: .notdef glyph
missing character: .notdef glyph
several ideas have been proposed:
1. keep U+FFFD
2. go back to U+2592
3. use U+25A1 instead
4. use U+FFFD if possible else fallback to U+2592 or U+25A1
if we choose option 1, people not happy with the ambiguity can simply install
"dejavu-fonts" or similar, which Cygwin provides.
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next prev parent reply other threads:[~2018-09-04 23:29 UTC|newest]
Thread overview: 62+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-01 16:13 Steven Penny
2018-09-01 18:11 ` Thomas Wolff
2018-09-01 18:46 ` Steven Penny
2018-09-01 21:07 ` Thomas Wolff
2018-09-01 19:40 ` Corinna Vinschen
2018-09-01 21:50 ` Doug Henderson
2018-09-01 22:49 ` Steven Penny
2018-09-02 8:07 ` Thomas Wolff
2018-09-02 12:51 ` Steven Penny
2018-09-03 12:46 ` Corinna Vinschen
2018-09-03 14:59 ` Corinna Vinschen
2018-09-03 16:34 ` Thomas Wolff
2018-09-03 17:17 ` Corinna Vinschen
2018-09-03 17:56 ` Thomas Wolff
2018-09-03 18:20 ` Thomas Wolff
2018-09-03 19:14 ` Corinna Vinschen
2018-09-03 20:27 ` Corinna Vinschen
2018-09-03 20:42 ` Thomas Wolff
2018-09-03 21:03 ` Corinna Vinschen
2018-09-03 22:15 ` Steven Penny
2018-09-04 6:06 ` Brian Inglis
2018-09-04 9:00 ` Corinna Vinschen
2018-09-04 11:40 ` Steven Penny
2018-09-05 7:55 ` Corinna Vinschen
2018-09-05 9:22 ` Thomas Wolff
2018-09-05 11:58 ` Steven Penny
2018-09-05 13:18 ` Marco Atzeri
2018-09-05 15:20 ` Andrey Repin
2018-09-05 15:58 ` Corinna Vinschen
2018-09-05 20:15 ` Corinna Vinschen
2018-09-06 1:35 ` Steven Penny
2018-09-06 7:01 ` Corinna Vinschen
2018-09-07 8:20 ` Corinna Vinschen
2018-09-07 10:34 ` Thomas Wolff
2018-09-07 11:29 ` Corinna Vinschen
2018-09-07 11:42 ` Thomas Wolff
2018-09-07 11:51 ` Thomas Wolff
2018-09-07 11:54 ` Corinna Vinschen
2018-09-07 16:22 ` Brian Inglis
2018-09-07 16:48 ` Brian Inglis
2018-09-07 17:01 ` Marco Atzeri
2018-09-07 18:21 ` Corinna Vinschen
2018-09-07 18:20 ` Corinna Vinschen
2018-09-05 13:35 ` Andrey Repin
2018-09-05 14:04 ` Houder
2018-09-05 15:05 ` Andrey Repin
2018-09-04 12:50 ` David Macek
2018-09-04 14:18 ` Thomas Wolff
2018-09-04 14:46 ` David Macek
2018-09-04 18:20 ` Steven Penny
2018-09-04 18:41 ` Thomas Wolff
2018-09-04 19:50 ` Andrey Repin
2018-09-04 19:53 ` Steven Penny
2018-09-04 21:43 ` Thomas Wolff
2018-09-04 23:29 ` Steven Penny [this message]
2018-09-04 20:40 ` Brian Inglis
2018-09-05 8:32 ` Corinna Vinschen
2018-09-04 13:05 ` Andrey Repin
2018-10-04 0:25 ` Steven Penny
2018-09-03 16:05 ` Brian Inglis
2018-09-04 19:59 ` Doug Henderson
2018-09-04 21:05 ` Steven Penny
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