hostname: -s: do not look up details via dns

This changes the hostname behavior to match other systems and its own
documentation.  Namely, that -s just parses the result of the active
gethostname() and does not attempt any network/DNS traffic.  Other
distros like Fedora/RedHat and Debian/Ubuntu have also changed their
behavior in this regard.

URL: https://bugzilla.redhat.com/319981
URL: https://bugzilla.redhat.com/531702
URL: https://bugs.debian.org/552482
URL: https://bugs.gentoo.org/515836

hostname.c

@@ -201,11 +201,6 @@ static void showhname(char *hname, int c)
     case 'f':
 	printf("%s\n", hp->h_name);
 	break;
-    case 's':
-	if (p != NULL)
-	    *p = '\0';
-	printf("%s\n", hp->h_name);
-	break;
     }
 }
 
@@ -392,7 +387,12 @@ int main(int argc, char **argv)
 	    fprintf(stderr, _("gethostname()=`%s'\n"), myname);
 	if (!type)
 	    printf("%s\n", myname);
-	else
+	else if (type == 's') {
+	    char *p = strchr(myname, '.');
+	    if (p)
+		*p = '\0';
+	    printf("%s\n", myname);
+	} else
 	    showhname(myname, type);
 	break;
     case 3: