[Xcb] FPE with clang

[Elias Pipping]

Hello,

I use awesome 3.4.4 as my window manager. It is linked against
xcb-util 0.3.6 with

  http://cgit.freedesktop.org/xcb/util/commit/?id=d5b5d682465bd3196105df86d6df9fcde9518e6c

applied (not applying it does not change anything about the outcome of
the procedure described below).

Running feh 1.3.4 inside xterm 258 makes awesome crash. Here's a backtrace:

Program received signal SIGFPE, Arithmetic exception.
0x00007ffff5ac977b in xcb_get_wm_size_hints_from_reply () from
/usr/lib/libxcb-icccm.so.1
(gdb) bt
#0  0x00007ffff5ac977b in xcb_get_wm_size_hints_from_reply () from
/usr/lib/libxcb-icccm.so.1
#1  0x00007ffff5ac9972 in xcb_get_wm_normal_hints_reply () from
/usr/lib/libxcb-icccm.so.1
#2  0x0000000000411559 in client_manage (w=8070800, wgeom=0x0,
phys_screen=0, L=0x0, L=0x0, oud=-1, ud=-1, L=0x0, opacity=0, cidx=-1,
L=0x0, reply=0x0, L=0x0)
#3  0x0000000000419d9c in event_handle_maprequest (connection=0x0,
ev=0x0, client=0, L=0x667c80)
#4  0x000000000040f57d in a_xcb_check_cb () at awesome.c:223
#5  0x00007ffff41b65b0 in ev_loop () from /usr/lib/libev.so.3
#6  0x000000000040f439 in main (argc=8070800, argv=0x0, flags=0,
exit_code=0) at awesome.c:572

and here's what dmesg has to say:

[   42.886387] awesome[4068] trap divide error ip:7f45eb41477b
sp:7fff548fbab0 error:0 in libxcb-icccm.so.1.0.0[7f45eb412000+4000]

My C compiler is clang

  clang version 2.0 (trunk 103466)
  Target: x86_64-pc-linux-gnu
  Thread model: posix

It's what I compiled xcb-util with. Compiling xcb-util with gcc 4.4.4
keeps the issue from occurring. What libxcb, awesome and feh are
compiled with does not appear to matter.

xcb-util passes `make check`; llvm and clang pass their respective
test suites, too.


Kind regards,

Elias Pipping