Comment 18 for bug 231484

Good news. I finally had time to figure out how to compile xorg myself. By checking the variable as described in the patch above, the crashes went away.

if (!kbd) {
xf86MsgVerb(X_WARNING, 0, "XkbHandleBell: Warning: kbd was NULL\n");
return;
}
if (!kbd->key) {
xf86MsgVerb(X_WARNING, 0, "XkbHandleBell: Warning: kbd->key was NULL\n");
return;
}

For every
* pressing of the 'Del' key without a char to delete after the cursor
* or pressing the 'backspace' key without a char to delete before the cursor,
the second message is added.

Of course I dont know if this silently corrupts the memory somewhere else.