12662 - Compatible characters not displayed

Status: VERIFIED WORKSFORME

(Core :: Internationalization, defect, P3)

Description

[Karl Ove Hufthammer]

Unicode contains a number of characters which doesn't exist in many fonts. Some
of these have one or more _compatible_ characters which can be used instead.
These are marked as <compat> in
<URL:ftp://ftp.unicode.org/Public/UNIDATA/UnicodeData-Latest.txt>.

Currently, when a character doesn't exist in a font, Mozilla uses the same
character from another font (usually Lucida Sana Unicode?) or doesn't render it
at all. It would be better if the the compatible characters were being used;
changing the font in the middle of a sentence doesn't look good.

Comment 1

[Karl Ove Hufthammer]

Attachment: Table of some characters along with their compatible characters

Comment 2

[Karl Ove Hufthammer]

Attachment: PNG image showing the same table

Comment 3

[Frank Tang]

>It would be better if the the compatible characters were being used;
>changing the font in the middle of a sentence doesn't look good.

Is this more or less a subjective view ? Someone else will argue the other way
around if we change it, right ?

Comment 4

[Karl Ove Hufthammer]

Of course it's a subjective view, though I don't think anybody will complain. E.g., I think most people who use a fi ligature would probably prefer to have this replaced with the letters f and i instead of an fi ligature from a different font (with different weight, heigt etc.).

Comment 5

[Karl Ove Hufthammer]

The new draft <URL:http://www.unicode.org/unicode/reports/tr20/> from Unicode
have more information on which characters should (and shouldn't) be substituted
using compatibility equivalents.

Comment 6

[Ben Bucksch (:BenB)]

huftis, can you point me to a graphical list of the characters? I have no idea,
about which chars we're talking.
Yout PNG doesn't display for me on eeyes and Mozilla.

Comment 7

[Karl Ove Hufthammer]

I've created a document with more information at
<URL:http://home.sol.no/~huftis/mozilla/compat.html>. There, you can find a
table showing some of the characters, along with their compatibility characters
(view it using Mozilla to see how the characters are currently being rendered).

Comment 8

[Frank Tang]

Window rendering FER . reassign to erik as M20

Comment 9

[Akkana Peck]

Is this really just a Windows rendering issue?  The issue of not displaying
these characters is, if anything, more pronounced on Unix platforms since the
default font doesn't handle most of these characters.

Comment 10

[Erik van der Poel]

This issue is not limited to Windows. Changing platform and OS fields.

Comment 11

[Erik van der Poel]

Moving all M16s to M17. Please make comments if you disagree.

Comment 12

[Frank Tang]

naoki is adding the support for transliteration into nsIEntityConverter now. see 
bug 9574 for details. The mapping table from Unicode (dec) to the 
transliteration will be placed into transliterate.properties file. Can some one 
add more stuff to that file ? Can someone think about how to use 
nsIEntityConverter for rendering fallback ?

Comment 13

[Erik van der Poel]

The important issues, such as displaying *something* (instead of nothing), and
mapping windows-1252 chars to appropriate glyphs on Unix, are logged as separate
bugs. The rest of this bug is relatively unimportant. Marking M20.

Comment 14

[Karl Ove Hufthammer]

New URL: http://home.no.net/huftis/mozilla/gammalt/compat.html

Comment 15

[Frank Tang]

Is this still a issue ? Should we file 3 bugs for each platform so we can trace 
it easier ?

Comment 16

[Karl Ove Hufthammer]

Yes, this is still an issue. See attached test case.

Comment 17

[Frank Tang]

erik resign. reassign all his bug to ftang for now.

Comment 18

[Frank Tang]

mark all future new as assigned after move from erik to ftang

Comment 19

[Karl Ove Hufthammer]

I believe this is still an issue, but can't check with the test case any longer, as I *have* fonts with the characters mentioned in the test case.

Comment 20

[Frank Tang]

I think the problem go away these day

Comment 21

[Teruko Kobayashi]

Changed QA contact to [e-mail].

Comment 22

[Yuying Long]

The page:
http://www.huftis.org/nynorsk-programvare/mozilla/gammalt/compat.html
display fine with me on all platforms on latest builds.

Mark as verified as worksForMe.