ref: 1eced86a4e6c7373ca3cd2caeb46a4a8367f13bb
dir: /sys/src/libString/s_terminate.c/
#include <u.h>
#include <libc.h>
#include "String.h"
void
s_terminate(String *s)
{
if(s->ref > 1)
sysfatal("can't s_terminate a shared string");
if (s->ptr >= s->end)
s_grow(s, 1);
*s->ptr = 0;
}