unserialize_uep(bufinfo_T *bi, int *error, char_u *file_name)
{
    int		i;
    u_entry_T	*uep;
    char_u	**array = NULL;
    char_u	*line;
    int		line_len;

    uep = (u_entry_T *)U_ALLOC_LINE(sizeof(u_entry_T));
    if (uep == NULL)
	return NULL;
    vim_memset(uep, 0, sizeof(u_entry_T));
#ifdef U_DEBUG
    uep->ue_magic = UE_MAGIC;
#endif
    uep->ue_top = undo_read_4c(bi);
    uep->ue_bot = undo_read_4c(bi);
    uep->ue_lcount = undo_read_4c(bi);
    uep->ue_size = undo_read_4c(bi);
    if (uep->ue_size > 0)
    {
	if (uep->ue_size < LONG_MAX / (int)sizeof(char_u *))
	    array = (char_u **)U_ALLOC_LINE(sizeof(char_u *) * uep->ue_size);
	if (array == NULL)
	{
	    *error = TRUE;
	    return uep;
	}
	vim_memset(array, 0, sizeof(char_u *) * uep->ue_size);
    }
    uep->ue_array = array;

    for (i = 0; i < uep->ue_size; ++i)
    {
	line_len = undo_read_4c(bi);
	if (line_len >= 0)
	    line = read_string_decrypt(bi, line_len);
	else
	{
	    line = NULL;
	    corruption_error("line length", file_name);
	}
	if (line == NULL)
	{
	    *error = TRUE;
	    return uep;
	}
	array[i] = line;
    }
    return uep;
}
The software performs a calculation that can produce an integer overflow or wraparound, when the logic assumes that the resulting value will always be larger than the original value. This can introduce other weaknesses when the calculation is used for resource management or execution control.