[Wine] multicore machines and libx11 crashes

[Dan Kegel]

I just got an i7, and it's giving me lots of crashes of the sort

Backtrace:
=>0 0x68000832 GLIBC_2+0x832() in ld-linux.so.2 (0x0e95f190)
  1 0x6819e932 (0x0e95f2b8)
  2 0x68194648 (0x0e95f300)
  3 0x68a5cfd3 in libx11.so.6 (+0x40fd3) (0x0e95f380)
  4 0x68a5d526 _XReply+0x106() in libx11.so.6 (0x0e95f3d0)
  5 0x68a14390 XShmQueryVersion+0x90() in libxext.so.6 (0x0e95f420)
  6 0x6897fe6e X11DRV_CreateDIBSection+0x175(physDev=0x8124d40,
hbitmap=0x42c8, bmi=0xe95f5d0, usage=0)
[/home/dank/wine-git/dlls/winex11.drv/dib.c:4772] in winex11
(0x0e95f4e0)
  7 0x683dee9a CreateDIBSection+0x4fc(hdc=0x42bc, bmi=<register EDI
not in topmost frame>, usage=0, bits=0x6508f1c, section=0x0(nil),
offset=0) [/home/dank/wine-git/dlls/gdi32/dib.c:1353] in gdi32
(0x0e95f580)

or maybe

*** glibc detected *** steam: free(): invalid pointer: 0x7cc54ae8 ***
======= Backtrace: =========
/lib/tls/i686/cmov/libc.so.6[0x681dbff1]
/lib/tls/i686/cmov/libc.so.6[0x681dd6f2]
/lib/tls/i686/cmov/libc.so.6(cfree+0x6d)[0x681e07cd]
/usr/lib/libX11.so.6[0x68df1eef]
/usr/lib/libX11.so.6(_XReply+0x106)[0x68df2526]
/usr/lib/libGL.so.1[0x20383f66]

or

xcb_io.c:378: _XAllocID: Assertion `ret != inval_id' failed.

probably because libx11 has a race condition that shows up
more readily on machines with more cores.

I hear this is a bug in libx11 that is fixed for Ubuntu 10.04, but the
fix has not yet
been backported to Ubuntu 9.10.

Lei Zhang has an ubuntu bug filed for the assertion, but I can't find
it at the moment to link to it :-(