621030 - anomalous character spacing (eg: Ta/Te/To/Tu)

Status: UNCONFIRMED

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

Description

[theguitar]

User-Agent:       Mozilla/5.0 (Windows NT 5.1; rv:2.0b8) Gecko/20100101 Firefox/4.0b8
Build Identifier: Mozilla/5.0 (Windows NT 5.1; rv:2.0b8) Gecko/20100101 Firefox/4.0b8

I notice an small letter's spacing before some chars that follow the capital letter "T" for address bar, search field, bookmarks, tab's titles etc. A bit 'everywhere. It's especially visible with the syllables Ta / Te / To / Tu.

Reproducible: Always

Steps to Reproduce:
1. Write "Ta", "Te", "To" or "Tu" in Address bar/Find field/Bookmarks title/etc

Comment 1

[(mostly gone) XtC4UaLL [:xtc4uall]]

What happens if you disable Hardware Acceleration in Tools/Options/Advanced/General and Restart Fx?
What happens if you set "gfx.font_rendering.harfbuzz.level" to "0" in about:config?
What's your Graphics Info from about:support (Bottom)?
Can you attach a Screenshot showing th Issue?

Comment 2

[theguitar]

(In reply to comment #1)
> What happens if you disable Hardware Acceleration in
> Tools/Options/Advanced/General and Restart Fx?
> What happens if you set "gfx.font_rendering.harfbuzz.level" to "0" in
> about:config?
> What's your Graphics Info from about:support (Bottom)?
> Can you attach a Screenshot showing th Issue?

When I disable Hardware Acceleration in Tools / Options / Advanced / General and restart firefox does not change anything. If I set "gfx.font_rendering.harfbuzz.level" to "0" the letters take on a normal spacing (I have swiched "Hardware Acceleration" but it seems irrelevant). Here are the screenshots URL: http://lospaziodifra.altervista.org/ffbug/621030/

Comment 3

[Jonathan Kew [:jfkthame]]

This is possibly just the correct application of kerning data that's present in the font (but is ignored by most older Windows applications). What font is your Windows system configured to use?

Comment 4

[theguitar]

My system font is Tahoma. More details to http://lospaziodifra.altervista.org/ffbug/621030/#font
I created a test page at http://lospaziodifra.altervista.org/ffbug/621030/TaTcTeToTgTrTuTvTwTy.html, and the Times New Roman is the only one who never changes.

Comment 5

[Joris Debonnet]

I have exactly the same problem as the OP, and experienced the exact same effects described in the next posts. I originally posted about 'my problem' on the MozillaZine forum, where someone refered me over here. A screenshot I made there contains the 'word' TwT which of course should be symmetrical, but is not with that config entry on its default value:
http://s4.postimage.org/2ozndf6ck/ff4letters_3.png

I have the issue with all the standard fonts that I tried, but do not have the issue in any other program, including IE8, Windows Explorer, Firefox 3.6, ... (on Windows XP). 

I also tried the test page from the post above, and can confirm the findings, HOWEVER Times New Roman is also affected starting from font-size 15px and higher (which is not included on that test page). So it's not immune to it either :)

Comment 6

[Joris Debonnet]

Apologies, I forgot to add my system info:

User Agent: Mozilla/5.0 (Windows NT 5.1; rv:2.0) Gecko/20100101 Firefox/4.0

Graphics:
Adapter Description: NVIDIA GeForce GTX 460
Vendor ID: 10de
Device ID: 0e22
Adapter RAM: Unknown
Adapter Drivers: nv4_disp
Driver Version: 6.14.12.6658
Driver Date: 1-7-2011
Direct2D Enabled: false
DirectWrite Enabled: false (0.0.0.0, font cache n/a)
WebGL Renderer: Google Inc. -- ANGLE -- OpenGL ES 2.0 (ANGLE 0.0.0.541)
GPU Accelerated Windows: 1/1 Direct3D 9

Comment 7

[Zio_Fede]

It happens to mee too.
Mozilla/5.0 (Windows NT 5.1; rv:2.0) Gecko/20100101 Firefox/4.0

Setting gfx.font_rendering.harfbuzz.level to 0 fixes the problem.

Comment 8

[dennis.tafel]

I do Webdesign, and it is very bad that text has a other lenght in FF4 as in all other Browser. Plz make a fix that the normal is standard.

Comment 9

[Joris Debonnet]

Someone on the MozillaZine forum noticed that the bug only appears on Windows XP SP3 with the Classic Win2000 layout (i.e. XP layout disabled). Thought I'd come and add this, in case it provides a clue to fix it (since I don't see a lot moving here? :) ).

Comment 10

[dennis.tafel]

i have the problem on Windows 7...

Comment 11

[qhaos]

"Someone on the MozillaZine forum noticed that the bug only appears on Windows XP SP3 with the Classic Win2000 layout (i.e. XP layout disabled)."

That's... odd.

I'll cosign this anyhow, since that's exactly what I'm using... and it happens with the letters T, Y and V. gfx.font_rendering.harfbuzz.level was already 0, so that didn't help, but setting gfx.font_rendering.harfbuzz.scripts to 0 did help.

Comment 12

[qhaos]

My system info is as follows:

Adapter Description: Intel(R) Q33 Express Chipset Family
Vendor ID: 8086
Device ID: 29d2
Adapter RAM: Unknown
Adapter Drivers: igxprd32
Driver Version: 6.14.10.5218
Driver Date: 1-13-2010
Direct2D Enabled: false
DirectWrite Enabled: false (0.0.0.0, font cache n/a)
WebGL Renderer: Google Inc. -- ANGLE -- OpenGL ES 2.0 (ANGLE 0.0.0.611)
GPU Accelerated Windows: 0/1

Comment 13

[al_9x]

Bug 639185 appears to be the same as this.  This issue is not limited to the Classic style.

Comment 14

[LummoxJR]

Changing the value of gfx.font_rendering.harfbuzz.scripts will help. I set mine to 0 and this issue went away. The problem is that while Firefox is respecting the font's own kerning, the kerning looks terrible--at least at small sizes. Changing the setting can tell the browser not to use the built-in kerning.

Comment 15

[Dan]

This is not confined to Tahoma font.  It also occurs with Times New Roman (and other fonts) at larger font sizes.  Try typing "ToT" in Times New Roman and enlarging to 20pt to see what I mean.  The lowercase o is not centered between the two Ts.

I think this is a harfbuzz bug in XP.  I don't think this is a font issue per say because the same fonts in Windows Vista/7 have correct spacing consistent with other browsers/programs.  I even copied the Windows 7 font file to XP in case MS made changes to the font between XP and 7.  Even with the Win7 font file copied to XP, the spacing is still off in XP.