490285 - First characters of each lines in non-ASCII pages are missing

Status: VERIFIED FIXED

(Firefox for Android Graveyard :: General, defect)

Description

[Takuro Ashie [:ashie]]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 6.0; ja; rv:1.9.0.8) Gecko/2009032609 Firefox/3.0.8 (.NET CLR 3.5.30729)
Build Identifier: 

When I open a certain page such as http://www.yahoo.co.jp, first character of all lines are missing.
This issue occurs with most Japanese page.


Reproducible: Always

Steps to Reproduce:
1. Open http://www.yahoo.co.jp by Fennec on WinCE
2. Open http://www.yahoo.co.jp by Firefox on Windows XP
3. Compare both results (characters count of each lines)

Actual Results:  
First character of each lines are missing.

Expected Results:  
Both results should be corresponded.

Comment 1

[Takuro Ashie [:ashie]]

Attachment: A screen shot of expected result (Firefox)

Comment 2

[Takuro Ashie [:ashie]]

Attachment: A screen shot of result on Fennec

Comment 3

[Takuro Ashie [:ashie]]

Attachment: Sample screen shot of result on fennec (with japanese font)

This screen shot uses Japanese font and a patch for https://bugzilla.mozilla.org/show_bug.cgi?id=490267 to show Japanese characters.

Comment 4

[Takuro Ashie [:ashie]]

Attachment: Another sample screen shot with default font settings

An interesting thing is that this issue doesn't occur when I specify default font by prefs.js and userContent.css.

prefs.js:

  user_pref("font.name.sans-serif.ja", "vl pgothic");
  user_pref("font.name.sans-serif.x-unicode", "vl pgothic");
  user_pref("font.name.sans-serif.x-western", "vl pgothic");
  user_pref("font.name.serif.ja", "vl pgothic");
  user_pref("font.name.serif.x-unicode", "vl pgothic");
  user_pref("font.name.serif.x-western", "vl pgothic");

userContent.css:

  input[name], input[value], select[name], option, textarea, button, fieldset, label, legend, optgroup[label] {
    font-family: 'VL PGothic', sans-serif;
    font-size: 12px;
  }

You can obtain VL PGothic from here:

  http://dicey.org/vlgothic/

Comment 5

[Takuro Ashie [:ashie]]

Attachment: A patch for missing characters issue

I've fixed this issue.

The problem is that all GlyphRuns in a TextRun is started from first character for the TextRun.

  http://hg.mozilla.org/mozilla-central/file/051f635a1061/gfx/thebes/src/gfxFT2Fonts.cpp#l550

So that later GlyphRuns erases/overrides former GlyphRuns, and finally only the last GlyphRuns is available in the TextRun.

I think it's a fatal issue for multiligual layout.

Comment 6

[Vladimir Vukicevic [:vlad] [:vladv] (needinfo me, slow to respond)]

Comment on attachment 375303 [details] [diff] [review]
A patch for missing characters issue

I think this is right, but I'd like karl or someone closer to the font code to also take a glance.

Comment 7

[Robert O'Callahan (:roc) (email my personal email if necessary)]

Do we need a test here? Do reftests actually pass on this platform without this patch?

Comment 8

[Robert O'Callahan (:roc) (email my personal email if necessary)]

http://hg.mozilla.org/mozilla-central/rev/d72e4c13d38e

Thanks, sorry about the delay.

Comment 9

[Aakash Desai [:aakashd]]

verified FIXED on builds:

Mozilla/5.0 (Macintosh; U; Intel Mac OSX 10.5; en-US; rv:1.9.2a2pre)
Gecko/20090808 Fennec/1.0b3pre

and

Mozilla/5.0 (X11; U; Linux armv6l; en-US; rv:1.9.3a1pre) Gecko/20090820
Fennec/1.0b3pre