Re: [Devel] [BUG?] Applications segfault when accessing pcf fonts.

[Frederic Crozat]

Le mer 28/07/2004 à 22:42, Ronald Hummelink a écrit :
> Good day,
> 
> I have been messing around with my gentoo systems. After I upgraded from 
> Freetype 2.1.7 to 2.1.9 mozilla and firefox started segfaulting when 
> accessing certain sites. It appears to make no difference to which 
> release the application was build. Firefox linux binaries from 
> mozilla.org also are affected. Not only mozilla seems to be affected, 
> the gnome font viewer also went down accessing specifically pcf fonts. I 
> traced down this is also what takes mozilla down.
> 
> Reverting freetype to 2.1.7 stabilised everything.
> 
> I went on the trial and error way in the hope to find which specific 
> commit between 2.1.7 and 2.1.9 that introduced this and came up with the 
> follwing commit:
> http://cvs.freetype.org/cgi-bin/viewcvs.cgi/freetype2/src/pcf/pcfdrivr.c.diff?r1=1.7&r2=1.8
> 
> If I revert this patch from 2.1.9 things appear stable, however i'm not 
> experienced enough with C to judge what side effects reverting this 
> patch have.
> 
> My experience with pcf fonts are confirmed by the distro bug report at 
> http://bugs.gentoo.org/show_bug.cgi?id=57796

It looks like an bug we had on Mdk cooker:
http://qa.mandrakesoft.com/show_bug.cgi?id=9652

it seems to be triggered by xorg Xft crashing when it compiles with its
own freetype copy (2.1.6 or 2.1.7, I'm not sure) but uses system
freetype (2.1.9) because it doesn't check for HAVE_FT_BITMAP_SIZE_Y_PPEM
(when compiling Xft inside xorg, its own configure isn't use, therefore,
the define isn't set).

I've been able to "fix" this problem by forcing
HAVE_FT_BITMAP_SIZE_Y_PPEM in xorg Xft compilation.

But when reading Xft changelog, you can find :
2004-03-19  Keith Packard  <address@hidden>
 
        * xftfreetype.c: (_XftSetFace): 
        Rework bitmap instance selection code to make it look prettier.
        Also, try both y_ppem/x_ppem *and* width/height to see
        which values will actually manage to load a font -- FreeType 
        2.1.7 has broken bdf/pcf loaders.

So, now, I'm not 100% sure where the bug is :)

Keith, could you give us more infos ?

-- 
Frederic Crozat <address@hidden>
Mandrakesoft