644857 - circumflex showing very badly on every online text (old versions of FreeSans font buggy)

Status: RESOLVED INVALID

(Core :: Layout: Text and Fonts, defect)

Description

[Jean-Bernard Marcon]

User-Agent:       Mozilla/5.0 (X11; Linux i686; rv:2.2a1pre) Gecko/20110324 Firefox/4.2a1pre
Build Identifier: Mozilla/5.0 (X11; Linux i686; rv:2.2a1pre) Gecko/20110324 Firefox/4.2a1pre

the circumflex accent which is quite common in French language and a number of other langs does not show correctly on last minefield update.

Reproducible: Always

Steps to Reproduce:
1. Open one page with some French text with FX 4.0 and spot soem circumflex chars (they are showing just fine)
Mark the page
2. Open this same page with Firefox/4.2a1pre

Actual Results:  
The circumflexed letters are strangely intermingled with other chars around so it makes a strange kind of unreadable char


I made some little tests to be sure it was a Firefox problem
- I opened the same page with Seamonkey and encountered no issue 
- I played with various combinations of default fonts in Firefox preferences, but the problem was still here

Comment 1

[Jean-Bernard Marcon]

Attachment: left is last minefield upadte - right is firefox 4.0

screenshot showing problem on last Minefield version compared to normal in FX 4.0

Comment 2

[Jonathan Kew [:jfkthame]]

This is almost certainly a regression from bug 635639. It would be helpful to identify the specific font being used on your system, as I don't think this happened in our existing testcases.

Comment 3

[Jean-Bernard Marcon]

Attachment: Minefield March 23rd version - ok

Comment 4

[Jean-Bernard Marcon]

Attachment: Minefield March 24th version - wrong

Comment 5

[Jean-Bernard Marcon]

(In reply to comment #2)
> This is almost certainly a regression from bug 635639. It would be helpful to
> identify the specific font being used on your system, as I don't think this
> happened in our existing testcases.

No problem with this build dating back from March 23rd 
Mozilla/5.0 (X11; Linux i686; rv:2.2a1pre) Gecko/20110323 Firefox/4.2a1pre
http://hg.mozilla.org/mozilla-central/rev/200a746e0fac


problem with this other buld (last available March 24th)
Mozilla/5.0 (X11; Linux i686; rv:2.2a1pre) Gecko/20110324 Firefox/4.2a1pre
http://hg.mozilla.org/mozilla-central/rev/0798b52bb40d

Default font FreeSans size 12
I did NOT checked the box "Allow pages to choose their own fonts, instead of my selections above"

Comment 6

[Jonathan Kew [:jfkthame]]

Thanks for the details. Are you seeing this problem on all pages, or only in cases where the circumflex is encoded as a separate diacritic (rather than using the precomposed vowel+circumflex character)?

As a test, please try
  data:text/html,côte côte
and confirm whether the problem shows up in both cases, or only the second.

Have you encountered this _only_ with the circumflex, or does it happen with other accents as well? I notice some letters with acute and grave accents in your screenshot where there does not seem to be any problem.

Comment 7

[Jean-Bernard Marcon]

(In reply to comment #6)
> Thanks for the details. Are you seeing this problem on all pages, or only in
> cases where the circumflex is encoded as a separate diacritic (rather than
> using the precomposed vowel+circumflex character)?
> 
> As a test, please try
>   data:text/html,côte côte
> and confirm whether the problem shows up in both cases, or only the second.
> 
> Have you encountered this _only_ with the circumflex, or does it happen with
> other accents as well? I notice some letters with acute and grave accents in
> your screenshot where there does not seem to be any problem.

(In reply to comment #6)
> Thanks for the details. Are you seeing this problem on all pages, or only in
> cases where the circumflex is encoded as a separate diacritic (rather than
> using the precomposed vowel+circumflex character)?
> 
> As a test, please try
>   data:text/html,côte côte
> and confirm whether the problem shows up in both cases, or only the second.
> 
> Have you encountered this _only_ with the circumflex, or does it happen with
> other accents as well? I notice some letters with acute and grave accents in
> your screenshot where there does not seem to be any problem.

- I changed my font for DejaVu Sans and there is no more circumflex problem. So I am sorry guys for useless noise
- For the record, yes only circumflex was affected and no other diacritic
- If any test is still necessary, just ask, but about this 
 As a test, please try
>   data:text/html,côte côte
I don't know how to do it, What shall I do exactly? enter these chars in a textarea? (I am no hacker)

Comment 8

[Jean-Bernard Marcon]

Attachment: with FreeSans font (wrong)

Comment 9

[Jean-Bernard Marcon]

Attachment: with DejaVu - good

Comment 10

[Jean-Bernard Marcon]

ah ok I dropped the char test in the address bar (silly me) and zoomed it before screenshots. Both done with same minefield most recent build.
So it is definitely a font displaying problem (but which did not show on 23rd March version of minefield)

Comment 11

[Jonathan Kew [:jfkthame]]

(In reply to comment #8)
> Created attachment 521760 [details]
> with FreeSans font (wrong)

Oh, so the _first_ version of the word displays incorrectly there! That's the opposite of what I expected. This almost certainly indicates an error in the OpenType tables of the FreeSans font; I'll take a look at it and verify this.

(And I do not consider this report to be "useless noise" at all.... it's important for us to understand why a problem like this happened, regardless of whether the real error is in Mozilla code or in the font. So thanks for reporting it and following up on the questions.)

Comment 12

[Jonathan Kew [:jfkthame]]

This is an error in the GDEF table of the FreeSans font (I'm guessing it may occur in others of the FreeFont collection as well, if they're all constructed in a similar way, but I didn't examine all the faces). The problem is that the "ocircumflex" glyph (and some other accented letters, but not all of them) is incorrectly marked as being a combining-mark glyph, and therefore we now force its advance width to be zero. This was done to fix specific rendering problems with some other fonts.

Fortunately, although I see this error in the freefont-20090104 release, it appears to have been corrected in the newer freefont-20100919 version. So I believe that updating your copy of FreeSans (and the rest of the freefont collection) to the latest release should resolve the problem.

Comment 13

[[:Aleksej]]

Removing regressionwindow-wanted, as it seems to not be needed now.

Comment 14

[[:Aleksej]]

If I tested correctly (on Debian), indeed it can be reproduced with ttf-freefont 20090104-7 but not 20100919-1 with
Mozilla/5.0 (X11; Linux x86_64; rv:6.0a2) Gecko/20110526 Firefox/6.0a2

Comment 15

[[:Aleksej]]

(In reply to comment #14)
(the problem appeared in the second word of "ôte côte")

Comment 16

[[:Aleksej]]

(In reply to Aleksej [:Aleksej] from comment #15)
> (In reply to comment #14)
> (the problem appeared in the second word of "ôte côte")

"ôte côte"?! Maybe I was seeing both this bug and something else…

Here is the test string modified to work with Firefox 6.0+: data:text/html,c&%23xf4;te&%23x20;co&%23x302;te

Works for me with Mozilla/5.0 (X11; Linux x86_64; rv:9.0a1) Gecko/20110901 Firefox/9.0a1 with freefont 2010919

Jonathan, should this bug be resolved INVALID?

Comment 17

[Jonathan Kew [:jfkthame]]

(In reply to Aleksej [:Aleksej] from comment #16)

> Jonathan, should this bug be resolved INVALID?

Yes - this was caused by font errors, not a Firefox bug.