This only occurs in specific circumstances where the number of bytes to be added
to a t_buffer via the ft_buffer_push_buf function is exactly equal to the number
of free bytes in the current underlying buffer. This does not occur if the
number of bytes to add to the buffer is smaller than that, since we allocate new
space using ft_calloc.
In these circumstances, since no terminating null byte is added, other code may
read past the end of the buffer, causing a buffer overflow.