[Fontconfig] crash on fontconfig 2.4.2 loading cache created by fontconfig 2.6.99

[Jan Słupski]

Hi,

I have an application that is compiled against fontconfig 2.4.2
and because of some other dependencies I don't want upgrade it ATM.

Lately I have upgraded my system to new Fedora 11 that uses
fontconfig packaged as "fontconfig-2.6.99.behdad.20090508-1.fc11.x86_64".

It seems that both system and my fontconfig use the same cache directories.

And now - if the cache is generated by the system (2.6.99) fontconfig,
my application crashes. If I cleanup those directories
(rm -rf /var/cache/fontconfig/* ~/.fontconfig/*), the app regenerates the cache
in my home directory (I assume using it's own 2.4.2 fontconfig) and runs ok.
It start crashing again once some other system application is started (i.e. firefox)
and refresh the cache.


Here is the call stack:

Program received signal SIGSEGV, Segmentation fault.
0x00007ffff7b507df in IA__FcStrListCreate () from .../generated/lib/libfontconfig.so.1
(gdb) bt
#0  0x00007ffff7b507df in IA__FcStrListCreate () from .../generated/lib/libfontconfig.so.1
#1  0x00007ffff7b45b10 in IA__FcLangSetHasLang () from .../generated/lib/libfontconfig.so.1
#2  0x00007ffff7b47ff2 in FcCompareLang () from .../generated/lib/libfontconfig.so.1
#3  0x00007ffff7b4842d in FcCompareValueList () from .../generated/lib/libfontconfig.so.1
#4  0x00007ffff7b48804 in FcCompare () from .../generated/lib/libfontconfig.so.1
#5  0x00007ffff7b48c5b in IA__FcFontSetMatch () from .../generated/lib/libfontconfig.so.1
#6  0x00007ffff7b48f02 in IA__FcFontMatch () from .../generated/lib/libfontconfig.so.1
#7  0x00007ffff7d9c36d in _cairo_fontconfig_scaled_font_create_toy () from .../generated/lib/libcairo.so.2

Both system (2.6.99) & mine (2.4.2) libraries are x86_64.



I know that I'm writing about unstable release, but with Fedora 11 it is
now very "exposed".
Let me know if you would like to investigate that further
and if so I can try to give more debugging details.



Jan Slupski