static inline
    SilcBuffer silc_buffer_srealloc(SilcStack stack,
                                    SilcBuffer sb, SilcUInt32 newsize);

    Reallocates buffer. Old data is saved into the new buffer. The buffer
    is exact clone of the old one except that there is now more space
    at the end of buffer.

    This routine use SilcStack are memory source.  If `stack' is NULL
    reverts back to normal allocating routine.