Debian Bug report logs - #362569
'fi' and 'fl' ligatures overlap following glyph with justified text in pango builds

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Message #5 received at submit@bugs.debian.org (full text, mbox, reply):

From: Martin Orr <martin@martinorr.name>

To: Debian Bug Tracking System <submit@bugs.debian.org>

Subject: fontconfig: DejaVu ligature width miscalculated

Date: Fri, 14 Apr 2006 10:37:19 +0100

[Message part 1 (text/plain, inline)]

Package: fontconfig
Version: 2.3.2-2
Severity: normal

The width of fi and fl ligatures is miscalculated when displaying
justify-aligned text in a DejaVu font in Firefox.  This happens with both
DejaVu Sans and DejaVu Serif, but not with other fonts.  I believe that this
is a fontconfig bug because it is present when fontconfig and libfontconfig1
2.3.2-2 or later are installed, but not with 2.3.2-1.1.

A simple test case is attached.

-- System Information:
Debian Release: testing/unstable
  APT prefers unstable
  APT policy: (500, 'unstable'), (500, 'testing'), (1, 'experimental')
Architecture: amd64 (x86_64)
Shell:  /bin/sh linked to /bin/bash
Kernel: Linux 2.6.16
Locale: LANG=en_GB.UTF-8, LC_CTYPE=en_GB.UTF-8 (charmap=UTF-8)

Versions of packages fontconfig depends on:
ii  defoma                        0.11.8-0.1 Debian Font Manager -- automatic f
ii  fontconfig-config             2.3.2-5.1  generic font configuration library
ii  libc6                         2.3.6-6    GNU C Library: Shared libraries
ii  libfontconfig1                2.3.2-5.1  generic font configuration library

fontconfig recommends no packages.

-- debconf information:
* fontconfig/subpixel_rendering: Automatic
* fontconfig/enable_bitmaps: false
* fontconfig/hinting_type: Native

[test.html (text/html, attachment)]

Message #10 received at 362569@bugs.debian.org (full text, mbox, reply):

From: Martin Orr <martin@martinorr.name>

To: 362569@bugs.debian.org

Subject: Re: Bug#362569: fontconfig: DejaVu ligature width miscalculated

Date: Sat, 15 Apr 2006 12:03:35 +0100

Sorry, it seems I failed to properly test this bug.  The reason why it
appeared to break going from 2.3.2-1.1 to 2.3.2-2 was because the default
fonts changed to DejaVu.  In fact, DejaVu spacing is wrong with 2.3.2-1.1 as
well as later fontconfig versions.  So this is probably a DejaVu bug.

-- 
Martin Orr

Message #15 received at 362569@bugs.debian.org (full text, mbox, reply):

From: Josselin Mouette <joss@debian.org>

To: Martin Orr <martin@martinorr.name>, 362569@bugs.debian.org

Cc: ttf-dejavu@packages.debian.org

Subject: Re: Bug#362569: fontconfig: DejaVu ligature width miscalculated

Date: Sun, 16 Apr 2006 17:43:30 +0200

[Message part 1 (text/plain, inline)]

reassign 362569 ttf-dejavu
thanks

Le samedi 15 avril 2006 à 12:03 +0100, Martin Orr a écrit :
> Sorry, it seems I failed to properly test this bug.  The reason why it
> appeared to break going from 2.3.2-1.1 to 2.3.2-2 was because the default
> fonts changed to DejaVu.  In fact, DejaVu spacing is wrong with 2.3.2-1.1 as
> well as later fontconfig versions.  So this is probably a DejaVu bug.

Thanks, I'm reassigning.

Regards,
-- 
 .''`.           Josselin Mouette        /\./\
: :' :           josselin.mouette@ens-lyon.org
`. `'                        joss@debian.org
  `-  Debian GNU/Linux -- The power of freedom

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Message #22 received at 362569@bugs.debian.org (full text, mbox, reply):

From: Josselin Mouette <joss@debian.org>

To: Peter Černák <pcernak@gmail.com>

Cc: 362569@bugs.debian.org, glandium@debian.org, keithp@debian.org

Subject: Re: Bug#362569: fontconfig: DejaVu ligature width miscalculated

Date: Sun, 16 Apr 2006 19:16:51 +0200

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Le dimanche 16 avril 2006 à 19:08 +0200, Peter Černák a écrit :
> 2006/4/16, Josselin Mouette <joss@debian.org>:
> > reassign 362569 ttf-dejavu
> > thanks
> >
> > Le samedi 15 avril 2006 à 12:03 +0100, Martin Orr a écrit :
> > > Sorry, it seems I failed to properly test this bug.  The reason why it
> > > appeared to break going from 2.3.2-1.1 to 2.3.2-2 was because the default
> > > fonts changed to DejaVu.  In fact, DejaVu spacing is wrong with 2.3.2-1.1 as
> > > well as later fontconfig versions.  So this is probably a DejaVu bug.
> >
> > Thanks, I'm reassigning.
> >
> 
> Isn't this rather a bug in firefox? (see
> http://sourceforge.net/mailarchive/forum.php?thread_id=10152634&forum_id=40874)

Probably, but I wouldn't be the one to be sure. I'm CCing some people
who probably know better than me about font mysteries and mozilla.

Regards,
-- 
 .''`.           Josselin Mouette        /\./\
: :' :           josselin.mouette@ens-lyon.org
`. `'                        joss@debian.org
  `-  Debian GNU/Linux -- The power of freedom

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Message #27 received at 362569@bugs.debian.org (full text, mbox, reply):

From: Mike Hommey <mh@glandium.org>

To: Josselin Mouette <joss@debian.org>

Cc: Peter Černák <pcernak@gmail.com>, 362569@bugs.debian.org, keithp@debian.org

Subject: Re: Bug#362569: fontconfig: DejaVu ligature width miscalculated

Date: Sun, 16 Apr 2006 21:00:00 +0200

On Sun, Apr 16, 2006 at 07:16:51PM +0200, Josselin Mouette <joss@debian.org> wrote:
> Le dimanche 16 avril 2006 à 19:08 +0200, Peter Černák a écrit :
> > 2006/4/16, Josselin Mouette <joss@debian.org>:
> > > reassign 362569 ttf-dejavu
> > > thanks
> > >
> > > Le samedi 15 avril 2006 à 12:03 +0100, Martin Orr a écrit :
> > > > Sorry, it seems I failed to properly test this bug.  The reason why it
> > > > appeared to break going from 2.3.2-1.1 to 2.3.2-2 was because the default
> > > > fonts changed to DejaVu.  In fact, DejaVu spacing is wrong with 2.3.2-1.1 as
> > > > well as later fontconfig versions.  So this is probably a DejaVu bug.
> > >
> > > Thanks, I'm reassigning.
> > >
> > 
> > Isn't this rather a bug in firefox? (see
> > http://sourceforge.net/mailarchive/forum.php?thread_id=10152634&forum_id=40874)
> 
> Probably, but I wouldn't be the one to be sure. I'm CCing some people
> who probably know better than me about font mysteries and mozilla.

I don't about the mozilla handling of fonts here, but I know I read
stuff about wrong ligatures in the deja-vu font. I just can't remember
where.

Mike

Message #32 received at 362569@bugs.debian.org (full text, mbox, reply):

From: Mike Hommey <mh@glandium.org>

To: Josselin Mouette <joss@debian.org>

Cc: Peter Černák <pcernak@gmail.com>, 362569@bugs.debian.org, keithp@debian.org

Subject: Re: Bug#362569: fontconfig: DejaVu ligature width miscalculated

Date: Mon, 17 Apr 2006 23:36:33 +0200

reassign 362569 firefox
forwarded 362569 https://bugzilla.mozilla.org/show_bug.cgi?id=331716
tag 362569 upstream
clone 362569 -1
reassign -1 libxul0d
thanks

On Sun, Apr 16, 2006 at 09:00:00PM +0200, Mike Hommey <mh@glandium.org> wrote:
> On Sun, Apr 16, 2006 at 07:16:51PM +0200, Josselin Mouette <joss@debian.org> wrote:
> > Le dimanche 16 avril 2006 à 19:08 +0200, Peter Černák a écrit :
> > > 2006/4/16, Josselin Mouette <joss@debian.org>:
> > > > reassign 362569 ttf-dejavu
> > > > thanks
> > > >
> > > > Le samedi 15 avril 2006 à 12:03 +0100, Martin Orr a écrit :
> > > > > Sorry, it seems I failed to properly test this bug.  The reason why it
> > > > > appeared to break going from 2.3.2-1.1 to 2.3.2-2 was because the default
> > > > > fonts changed to DejaVu.  In fact, DejaVu spacing is wrong with 2.3.2-1.1 as
> > > > > well as later fontconfig versions.  So this is probably a DejaVu bug.
> > > >
> > > > Thanks, I'm reassigning.
> > > >
> > > 
> > > Isn't this rather a bug in firefox? (see
> > > http://sourceforge.net/mailarchive/forum.php?thread_id=10152634&forum_id=40874)
> > 
> > Probably, but I wouldn't be the one to be sure. I'm CCing some people
> > who probably know better than me about font mysteries and mozilla.
> 
> I don't about the mozilla handling of fonts here, but I know I read
> stuff about wrong ligatures in the deja-vu font. I just can't remember
> where.

It appears to be a firefox bug (and libxul0d, btw). Tagging accordingly.

Thanks

Mike

Message #49 received at 362569@bugs.debian.org (full text, mbox, reply):

From: Jan Willem Stumpel <jstumpel@planet.nl>

To: 362569@bugs.debian.org

Subject: It is most probably a firefox bug

Date: Sat, 15 Jul 2006 17:36:34 +0200

This bug was reported earlier on Ubuntu
(https://launchpad.net/distros/ubuntu/+source/firefox/+bug/37828),
also in connnection with the dejavu fonts.

It does not occur anymore (in Debian Sid) with the dejavu fonts,
because the dejavu people have disabled automatic ligatures in the
more recent versions of their fonts.

However, the bug still occurs if you use the ttf-freefonts
(FreeSans and FreeSerif).

A web page in which the text is *not* justified is displayed
beautifully, with "fi" represented by a ligature, if you use
FreeSerif as the default "Western" font in Firefox. However, if
the web page specifies justified text, Firefox makes a mess of
ligatures when using the freefonts.

I suggested to the freefonts maintainer to disable automatic
ligatures in the freefonts also, at least for the time being
(http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=254113;msg=389)
Unfortunately even if this were done, it would just be a
work-around, not a cure, because it would mean sacrificing
ligature substitution entirely (as dejavu now has done). Ligature
substitution works well e.g. in gedit, and also in Firefox if text
is not justified. The real cause of the bug is, IMHO, within
Firefox. It can handle ligatures correctly with non-justified
text; now it should also do it with justified text.

Regards, Jan

Message #58 received at 362569@bugs.debian.org (full text, mbox, reply):

From: Ben Finney <ben@benfinney.id.au>

To: 362569@bugs.debian.org

Subject: Still occurring with DejaVu fonts

Date: Tue, 30 Jan 2007 09:55:26 +1100

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Jan Willem Stumpel <jstumpel@planet.nl> wrote:
> It does not occur anymore (in Debian Sid) with the dejavu fonts,
> because the dejavu people have disabled automatic ligatures in the
> more recent versions of their fonts.

I've recently upgraded (Debian 'etch') to 'ttf-dejavu' version 2.13-1,
and the described problem now occurs again: Iceweasel (2.0.0.1+dfsg-2)
renders ligature widths incorrectly in full-justified text.

-- 
 \       "A 'No' uttered from deepest conviction is better and greater |
  `\       than a 'Yes' merely uttered to please, or what is worse, to |
_o__)                               avoid trouble."  -- Mahatma Gandhi |
Ben Finney <ben@benfinney.id.au>

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Message #65 received at 362569@bugs.debian.org (full text, mbox, reply):

From: Ben Finney <ben@benfinney.id.au>

To: 362569@bugs.debian.org

Subject: Example of rendering bug

Date: Fri, 2 Mar 2007 09:53:46 +1100

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Howdy,

Here is an example page displaying the bug on my system:

    <URL:http://bignose.whitetree.org/tmp/debian-bug-362529.html>

That page contains example paragraphs, one with words that will result 
in ligatures and one without. The style sheet for the page suggests 
"font-family: Deja Vu Sans" for the text, and "text-align: justify" 
for the two example paragraphs.

On my system (Firefox is iceweasel 2.0.0.1+dfsg-2, Deja Vu fonts are 
ttf-dejavu 2.14-2) the page renders as shown in this image:

    <URL:http://bignose.whitetree.org/tmp/debian-bug-362529.png>

Note that the first example paragraph has ligatures overlapping the 
characters that follow, and that the justified text is rendered such 
that the first line of the paragraph is narrower than those following. 
The example paragraph with no ligatures renders with the first line 
the same width as those that follow.

Correct rendering of the font would have no overlapping characters, 
and both example paragraphs would have first lines the same width.

-- 
 \        "First things first, but not necessarily in that order."  -- |
  `\                                          The Doctor, _Doctor Who_ |
_o__)                                                                  |
Ben Finney <ben@benfinney.id.au>

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Message #70 received at 362569@bugs.debian.org (full text, mbox, reply):

From: Ben Finney <ben@benfinney.id.au>

To: 362569@bugs.debian.org

Subject: Example of rendering bug

Date: Fri, 2 Mar 2007 10:01:32 +1100

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Howdy,

To make things simpler, I'll attach both files so they're accessible 
directly from this bug report.

-- 
 \        "First things first, but not necessarily in that order."  -- |
  `\                                          The Doctor, _Doctor Who_ |
_o__)                                                                  |
Ben Finney <ben@benfinney.id.au>

[debian-bug-362529.html (text/html, attachment)]

[debian-bug-362529.png (image/png, attachment)]

Message #75 received at 362569@bugs.debian.org (full text, mbox, reply):

From: Ben Finney <ben@benfinney.id.au>

To: 362569@bugs.debian.org

Subject: Re: Example of rendering bug

Date: Wed, 14 Mar 2007 10:00:23 +1100

[Message part 1 (text/plain, inline)]

On 02-Mar-2007, Ben Finney wrote:
> On my system (Firefox is iceweasel 2.0.0.1+dfsg-2, Deja Vu fonts are 
> ttf-dejavu 2.14-2) the page renders as shown in this image:

I've now upgraded to ttf-dejavu 2.51-1 from 'etch', and the bug is 
still occurring as described.

-- 
 \        "No matter how cynical you become, it's never enough to keep |
  `\                             up."  -- Jane Wagner, via Lily Tomlin |
_o__)                                                                  |
Ben Finney <ben@benfinney.id.au>

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Message #80 received at 362569@bugs.debian.org (full text, mbox, reply):

From: Ben Finney <ben@benfinney.id.au>

To: 362569@bugs.debian.org

Subject: Re: Example of rendering bug

Date: Wed, 14 Mar 2007 10:01:59 +1100

[Message part 1 (text/plain, inline)]

On 14-Mar-2007, Ben Finney wrote:
> On 02-Mar-2007, Ben Finney wrote:
> > On my system (Firefox is iceweasel 2.0.0.1+dfsg-2, Deja Vu fonts 
> > are ttf-dejavu 2.14-2) the page renders as shown in this image:
> 
> I've now upgraded to ttf-dejavu 2.51-1 from 'etch', and the bug is 
> still occurring as described.

Er, okay, so my time machine isn't as good as first claimed. I've 
actually upgraded to ttf-dejavu 2.15-1. The bug occurs as described 
previously.

-- 
 \            "There are always those who think they know what is your |
  `\       responsibility better than you do."  -- Ralph Waldo Emerson |
_o__)                                                                  |
Ben Finney <ben@benfinney.id.au>

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Message #85 received at 362569@bugs.debian.org (full text, mbox, reply):

From: Benjamin Cama <benoar@free.fr>

To: 362569@bugs.debian.org

Subject: Some precision

Date: Thu, 15 Mar 2007 04:45:12 +0100

Happens here too, latest etch at this time.
I noted that the problem doesn't occur if the unicode character of the
ligature is directly inserted (for example ffi for ffi).
Disabling pango leads to correct font displaying, but without the
ligature. By the way, the MOZ_DISABLE_PANGO env var disable pango if it
is just set, not if it set to 0 (which doesn't enable pango).

Message #92 received at 362569@bugs.debian.org (full text, mbox, reply):

From: Bastian Venthur <venthur@debian.org>

To: 362569@bugs.debian.org, eric@debian.org

Subject: any news?

Date: Fri, 22 Jun 2007 16:06:36 +0200

Package: iceweasel
Version: 2.0.0.4-1

--- Please enter the report below this line. ---
Hi,

this crappy font rendering bug has been open for nearly 1,5 years now.
It is pretty annoying, especially when reading Planet Debian. Is the
source of the problem still unknown?

I can confirm that starting icedove with MOZ_DISABLE_PANGO=1 set, solves
the problem.


Cheers,

Bastian

PS: Please CC me!

--- System information. ---
Architecture: i386
Kernel:       Linux 2.6.21-1-k7

Debian Release: lenny/sid
  500 unstable        www.debian-multimedia.org
  500 unstable        ftp.de.debian.org
    1 experimental    ftp.de.debian.org

--- Package information. ---
Depends                         (Version) | Installed
=========================================-+-====================
fontconfig                                | 2.4.2-1.2
psmisc                                    | 22.5-1
debianutils                     (>= 1.16) | 2.21
libatk1.0-0                   (>= 1.13.2) | 1.18.0-2
libc6                          (>= 2.5-5) | 2.5-11
libcairo2                      (>= 1.4.0) | 1.4.8-1
libfontconfig1                 (>= 2.4.0) | 2.4.2-1.2
libfreetype6                     (>= 2.2) | 2.2.1-6
libgcc1               (>= 1:4.2-20070516) | 1:4.2-20070609-1
libglib2.0-0                  (>= 2.12.9) | 2.12.12-1
libgtk2.0-0                   (>= 2.10.3) | 2.10.13-1
libhunspell-1.1-0            (>= 1.1.5-1) | 1.1.5-6
libjpeg62                                 | 6b-13
libnspr4-0d                 (>= 1.8.0.10) | 4.6.6-3
libnss3-0d                  (>= 3.11.5-1) | 3.11.5-3
libpango1.0-0                 (>= 1.16.4) | 1.16.4-1
libpng12-0                  (>= 1.2.13-4) | 1.2.15~beta5-2
libstdc++6              (>= 4.2-20070516) | 4.2-20070609-1
libx11-6                                  | 2:1.0.3-7
libxft2                        (>> 2.1.1) | 2.1.12-2
libxinerama1                              | 1:1.0.2-1
libxp6                                    | 1:1.0.0.xsf1-1
libxrender1                               | 1:0.9.2-1
libxt6                                    | 1:1.0.5-3
zlib1g                       (>= 1:1.2.1) | 1:1.2.3-15


-- 
Bastian Venthur                                      http://venthur.de
Debian Developer                                 venthur at debian org

Message #97 received at 362569@bugs.debian.org (full text, mbox, reply):

From: Mike Hommey <mh@glandium.org>

To: Bastian Venthur <venthur@debian.org>, 362569@bugs.debian.org

Cc: eric@debian.org

Subject: Re: Bug#362569: any news?

Date: Fri, 22 Jun 2007 18:35:18 +0200

On Fri, Jun 22, 2007 at 04:06:36PM +0200, Bastian Venthur <venthur@debian.org> wrote:
> Package: iceweasel
> Version: 2.0.0.4-1
> 
> --- Please enter the report below this line. ---
> Hi,
> 
> this crappy font rendering bug has been open for nearly 1,5 years now.
> It is pretty annoying, especially when reading Planet Debian. Is the
> source of the problem still unknown?

According to upstream bug log, it should be fixed with the new textframe
code, in Firefox 3.0...

Mike

Message #102 received at 362569@bugs.debian.org (full text, mbox, reply):

From: Bastian Venthur <venthur@debian.org>

To: Mike Hommey <mh@glandium.org>

Cc: 362569@bugs.debian.org, eric@debian.org

Subject: Re: Bug#362569: any news?

Date: Fri, 22 Jun 2007 19:24:11 +0200

Mike Hommey wrote:
> On Fri, Jun 22, 2007 at 04:06:36PM +0200, Bastian Venthur <venthur@debian.org> wrote:

>> this crappy font rendering bug has been open for nearly 1,5 years now.
>> It is pretty annoying, especially when reading Planet Debian. Is the
>> source of the problem still unknown?
> 
> According to upstream bug log, it should be fixed with the new textframe
> code, in Firefox 3.0...

Oh great! :/

What's with the workaround MOZ_DISABLE_PANGO=1? Any reason not to use it
by default? I've heard that this also solves some rendering problems
with non-latin fonts.


Thanks for your update, anyway.


Cheers,

Bastian


-- 
Bastian Venthur                                      http://venthur.de
Debian Developer                                 venthur at debian org

Message #107 received at 362569@bugs.debian.org (full text, mbox, reply):

From: Mike Hommey <mh@glandium.org>

To: Bastian Venthur <venthur@debian.org>

Cc: 362569@bugs.debian.org, eric@debian.org

Subject: Re: Bug#362569: any news?

Date: Fri, 22 Jun 2007 19:29:47 +0200

On Fri, Jun 22, 2007 at 07:24:11PM +0200, Bastian Venthur <venthur@debian.org> wrote:
> Mike Hommey wrote:
> > On Fri, Jun 22, 2007 at 04:06:36PM +0200, Bastian Venthur <venthur@debian.org> wrote:
> 
> >> this crappy font rendering bug has been open for nearly 1,5 years now.
> >> It is pretty annoying, especially when reading Planet Debian. Is the
> >> source of the problem still unknown?
> > 
> > According to upstream bug log, it should be fixed with the new textframe
> > code, in Firefox 3.0...
> 
> Oh great! :/
> 
> What's with the workaround MOZ_DISABLE_PANGO=1? Any reason not to use it
> by default? I've heard that this also solves some rendering problems
> with non-latin fonts.

That's much more the contrary, which is why we keep the pango backend.

Mike

Message #112 received at 362569@bugs.debian.org (full text, mbox, reply):

From: Rich Felker <dalias@aerifal.cx>

To: 362569@bugs.debian.org

Subject: workaround

Date: Mon, 10 Sep 2007 21:28:52 -0400

Waiting for upstream to take their merry time to release 3.0 hardly
seems like a good way to deal with the problem to me. If fixing it
independently is too much work, how about just disabling justified
text completely when using Pango? I find it slows down the browser to
an almost unusable crawl in most cases anyway. If you don't want to do
this unconditionally, how about a MOZ_DISABLE_JUSTIFY environment
variable?

Message #137 received at 362569-done@bugs.debian.org (full text, mbox, reply):

From: Mike Hommey <mh@glandium.org>

To: 362569-done@bugs.debian.org

Subject: properly closing

Date: Tue, 22 Dec 2009 12:06:54 +0100

Version: 3.0~b4-1

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