ngets shall exit on EOF

[int0dh]

Hi All,

I`ve noted that ngets() from libstand starts consuming CPU like mad when
EOF appears on stdin. I see this issue with bhyveload when forwarding "user input" over pipe.
Here is the simpliest program to reproduce:

cat > ./bget.c

include <stdint.h>

include <unistd.h>

include <stdio.h>

include <sys/file.h>

int main()
{
char str[512];

    for (;;) {
            ngets(str, sizeof(str));
            if (str[0] == '\n')
                    break;
    }
    return 0;

}

$ echo "balbalbalabl" | ./bget &
$

You will see bget consuming CPU in ngets() reading EOF, basically because getchar()
returns EOF again and again. Suggested patch fixes the problem.

[bdrewery]

Duplicated in https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=198706

[bsdimp]

Since this has moved to bugzilla, I'm going to close this pull request. It also seems to have stalled there though. Maybe this email will illicit a response and it will get going again.