Bug 114658

Created attachment 13052 [details]
Konsole snapshot

In this snapshot you can see that konsole is being run with --noxft switch but
fonts are antialiased.

I have also KDE 3.4.2 installed from sources and this switch works OK.

I did an investigation and found out that this problem is possibly a QT/Xft/X.org problem.

Everyhting works right if my .fonts.conf file like like this (1):
<?xml version="1.0"?>
<!DOCTYPE fontconfig SYSTEM "fonts.dtd">
<fontconfig>
 <match target="font" >
  <edit mode="assign" name="hinting" >
   <bool>true</bool>
  </edit>
 </match>
 <match target="font" >
  <edit mode="assign" name="hintstyle" >
   <const>hintfull</const>
  </edit>
 </match>
 <match target="font" >
  <edit mode="assign" name="rgba" >
   <const>rgb</const>
  </edit>
 </match>
</fontconfig>

But when this file looks like this Konsole fonts are always antialiased (2):
<?xml version="1.0"?>
<!DOCTYPE fontconfig SYSTEM "fonts.dtd">
<fontconfig>
 <match target="font" >
  <edit mode="assign" name="rgba" >
   <const>rgb</const>
  </edit>
 </match>
 <match target="font" >
  <edit mode="assign" name="hinting" >
   <bool>true</bool>
  </edit>
 </match>
 <match target="font" >
  <edit mode="assign" name="hintstyle" >
   <const>hintfull</const>
  </edit>
 </match>
 <match target="font" >
  <edit mode="assign" name="antialias" >
   <bool>true</bool>
  </edit>
 </match>
</fontconfig>

To sort everything out I created a new user and logged under it to KDE. Then I run KControl and enabled antialiasing settings, that made KDE produce the file (1). When I relogon'ed and started KControl settings I disabled and reenabled antialiasing setting. Strangely this time KDE produced the file (2). And with the second file Konsole doesn't work properly ...

Here's the code Konsole uses for this:

void TEWidget::setVTFont(const QFont& f)
{
  QFont font = f;
  if (!s_antialias)
    font.setStyleStrategy( QFont::NoAntialias );
  QFrame::setFont(font);
  fontChange(font);
}

I would say this is a Qt/KDE/X issue.  Konsole can't really do anything about it.

Should we reassign the bug to someone else?

This bug persists in KDE 3.5.1/QT 3.3.5/X.org 6.8.2/Xft 2.8.1/fontconfig 2.2.3 as well.

*** This bug has been confirmed by popular vote. ***

This is the information I've just received from trolltech developer:

--------------------------------------------------------------------
I can reproduce the behavior you are experiencing using the file you
sent, but it is not actually a bug in Qt.

Calling QFont::setStyleStrategy() is just a hint to the font match
system about which fonts should be used, but if there is actually a
rule in the .fonts.conf file such as:

 <match target="font" >
  <edit mode="assign" name="antialias" >
   <bool>true</bool>
  </edit>
 </match>

Then Qt can not do anything about it because you are explicitly forcing
all fonts to be anti-aliased. To change this behavior, either remove
the above option from your .fonts.conf or put a size restriction on it
so that it only happens at certain sizes.

Regards,

--
Jason Barron, Support Engineer
Trolltech AS, Oslo - http://www.trolltech.com

--------------------------------------------------------------------

So indeed, it's KDE KCM Fonts module bug - it should not ever add this portion

 <match target="font" >
  <edit mode="assign" name="antialias" >
   <bool>true</bool>
  </edit>
 </match>

to the $HOME/.fonts.conf file.

Confirmed that removing the specified section from .fonts.conf fixes the problem.

Re-assigning to KControl / kcmfonts

This bug seems to be resolved in KDE 4.x