Comment 4 for bug 889250

void
StaticSwitchScreen::getWindowPosition (unsigned int index,
                                       int *x,
                                       int *y)
{
    int row, column;

    if (index >= windows.size ())
        return;

    column = (int)index % xCount;
    row = (int)index / xCount;

    *x = column * previewWidth + (column + 1) * previewBorder;
    *x += getRowXOffset (row);

    *y = row * previewHeight + (row + 1) * previewBorder;
}

That's two places for divbyzero in a row; both if xCount is zero. It looks like it's initialized to 0 and then has lots of opportunity to be zero later on. However, compiling the thing is apparently not as easy as typing `cmake .`. Crosses thumbs that I get away with not fixing this.