224924 - Superscripted and subscripted digits are rendered inconsistently

Status: RESOLVED WORKSFORME

(SeaMonkey :: General, defect)

Description

[Tom Blake]

User-Agent:       Mozilla/5.0 (Macintosh; U; PPC Mac OS X Mach-O; en-US; rv:1.5) Gecko/20030916
Build Identifier: Mozilla/5.0 (Macintosh; U; PPC Mac OS X Mach-O; en-US; rv:1.5) Gecko/20030916

In the page cited above, you will notice that all of the superscripted digits,
except "4" are rendered in a reasonably consistent manner. "4" on the other hand
seems to be too small, and is too far above the baseline (as if it were the
superscript of a superscript) in addition its kerning is different from the
other digits.

Among the subscripted digits, notice that "1" through "4" are too small, too
low, and have additional kerning.

Reproducible: Always

Steps to Reproduce:
1. (Open the web page cited above.)
2. (Examine the source if you like.)
Actual Results:  
The digits render inconsistently.

Expected Results:  
Rendered the digits consistently.

Comment 1

[Boris Zbarsky [:bzbarsky]]

This is a matter of what glyphs your font has for those characters... Also note
that the 1, 2, 3 come from a totally different Unicode range than the other
glyphs so I would not be surprised if the two sets of glyphs came from different
fonts...

Comment 2

[Boris Zbarsky [:bzbarsky]]

So I just checked.  On my Linux system, the only font that has the superscripts
other than 1,2,3 seems to be the B&H Lucida Sans Unicode font.  But in that
font, the 4, 5, 6, superscripts all look identical (according to xfd).  On the
other hand, I do see the problem with the "4" that Tom describes.

jshin, ideas?

Comment 3

[Tom Blake]

Attachment: Rendered With Mozilla

Notice funky kerning, and especially notice the superscripted 4.

Comment 4

[Tom Blake]

Attachment: The same code, rendered with Safari on the same machine

Notice that the superscripted 1, 2 & 3 seem slightly different (no great
surprise) however, other than that, things look pretty good.

Comment 5

[Jungshik Shin]

Hmm... that's strange.

With Xft build on my Linux box, it appears that 1..4 come from one font and 0,
5..7 come from the other. '6' has an odd positioning (not so much off-position
as Tom's screenshot) relative to 5 and 7. It could well be due to bad fonts. Or,
some kind of transliterating is done by Mozilla if glyphs don't exist. Mozilla
does some transliteration, but I'm not aware of a kind (synthesizing
sub/superscript digits out of normal glyphs) that might cause this bug.

I'll check which fonts are used. 

Tom, can you identify fonts used by Mozilla and Safari for sub/superscript digits?

Comment 6

[Tom Blake]

It appears that Sarari is using  Lucida Sans.
I haven't identified the typeface Mozilla is using yet.

Comment 7

[Jungshik Shin]

I forgot to tell you that it's a bad idea to use those characters in html/xhtml.
They wouldn't have been in the Unicode if no legacy character set had them.
(that is, they're included in the Unicode for the round-trip compatibility with
legacy character sets.)  In html/xhtml, it's a lot better to use <sub> and <sup>
tag. Then, you'll get a clean and consistent result. 

This is not to say that there's something we've gotta do here, but 

Comment 8

[Gervase Markham [:gerv]]

This is an automated message, with ID "auto-resolve01".

This bug has had no comments for a long time. Statistically, we have found that
bug reports that have not been confirmed by a second user after three months are
highly unlikely to be the source of a fix to the code.

While your input is very important to us, our resources are limited and so we
are asking for your help in focussing our efforts. If you can still reproduce
this problem in the latest version of the product (see below for how to obtain a
copy) or, for feature requests, if it's not present in the latest version and
you still believe we should implement it, please visit the URL of this bug
(given at the top of this mail) and add a comment to that effect, giving more
reproduction information if you have it.

If it is not a problem any longer, you need take no action. If this bug is not
changed in any way in the next two weeks, it will be automatically resolved.
Thank you for your help in this matter.

The latest beta releases can be obtained from:
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Seamonkey:   http://www.mozilla.org/projects/seamonkey/

Comment 9

[Tom Blake]

Subscripted digits 0-9 are now all rendered consistently. (Yeah!)

Superscripted digits 1-4 are still rendered differently from superscripted 0 &
5-9. The problem exists with the latest versions of Firefox, Mozilla Suite,
Camino and Safari (suggesting the problem may now be one with Mac OS X.)