Comment 7 for bug 343528

I just saw this too, while doing nothing very special, just editing a text file. I'm taking the liberty of reassigning this over to xserver-xorg-input-evdev, which seems to include the function that's crashing.

The text of the function is short enough to paste here:

void EvdevMBEmuBlockHandler(pointer data,
                            struct timeval **waitTime,
                            pointer LastSelectMask)
{
    InputInfoPtr pInfo = (InputInfoPtr) data;
    EvdevPtr pEvdev= (EvdevPtr) pInfo->private;
    int ms;

    if (pEvdev->emulateMB.pending)
    {
        ms = pEvdev->emulateMB.expires - GetTimeInMillis ();
        if (ms <= 0)
            ms = 0;
        AdjustWaitForDelay (waitTime, ms);
    }
}